Principles of Principles of Preoperative and Preoperative and

Operative Surgery Operative Surgery Prof. Med. Nabil H. MohyeddinProf. Med. Nabil H. Mohyeddin

Anaesthesiologist & IntensivistAnaesthesiologist & IntensivistGermany, Rostock universityGermany, Rostock university

Four principles:Four principles:Preoperative Preparation of the Patient   Preoperative Preparation of the Patient   Systems Approach to Preoperative Systems Approach to Preoperative

Evaluation   Evaluation   Additional Preoperative Considerations  Additional Preoperative Considerations     Preoperative Checklist   Preoperative Checklist   

PREOPERATIVE PREOPERATIVE PREPARATION OF THE PREPARATION OF THE

PATIENT PATIENT The modern preparation of a patient The modern preparation of a patient

for surgery is epitomized by the for surgery is epitomized by the convergence of the art and science convergence of the art and science of the surgical discipline. The context of the surgical discipline. The context in which preoperative preparation is in which preoperative preparation is conducted ranges from an outpatient conducted ranges from an outpatient office visit to hospital inpatient office visit to hospital inpatient consultation to emergency consultation to emergency department evaluation of a patient.department evaluation of a patient.

Approaches to preoperative evaluation Approaches to preoperative evaluation differ significantly, depending on the differ significantly, depending on the nature of the complaint and the nature of the complaint and the proposed surgical intervention, patient proposed surgical intervention, patient health and assessment of risk factors, health and assessment of risk factors, and the results of directed and the results of directed investigation and interventions to investigation and interventions to optimize the patient's overall status optimize the patient's overall status and readiness for surgery. and readiness for surgery.

This chapter reviews the components This chapter reviews the components of risk assessment applicable to the of risk assessment applicable to the evaluation of any patient for surgery evaluation of any patient for surgery and attempts to provide some basic and attempts to provide some basic algorithms to aid in the preparation algorithms to aid in the preparation of patients for surgery. of patients for surgery.

Determining the Need for Determining the Need for SurgerySurgery

Patients are often referred to surgeons Patients are often referred to surgeons with a suspected surgical diagnosis and with a suspected surgical diagnosis and the results of supporting investigations the results of supporting investigations in hand. In this context, the surgeon's in hand. In this context, the surgeon's initial encounter with the patient may initial encounter with the patient may be largely directed toward confirmation be largely directed toward confirmation of relevant physical findings and review of relevant physical findings and review of the clinical history and laboratory of the clinical history and laboratory and investigative tests that support the and investigative tests that support the diagnosis. diagnosis.

A recommendation regarding the A recommendation regarding the need for operative intervention can need for operative intervention can then be made by the surgeon and then be made by the surgeon and discussed with the patient's family discussed with the patient's family members. A decision to perform members. A decision to perform additional investigative tests or additional investigative tests or consideration of alternative consideration of alternative therapeutic options may postpone the therapeutic options may postpone the decision for surgical intervention from decision for surgical intervention from this initial encounter to a later time this initial encounter to a later time

It is important for the surgeon to It is important for the surgeon to explain the context of the illness and explain the context of the illness and the benefit of different surgical the benefit of different surgical interventions, further investigation, interventions, further investigation, and possible nonsurgical and possible nonsurgical alternatives, when appropriate alternatives, when appropriate

The surgeon's approach to the patient The surgeon's approach to the patient and family during the initial encounter and family during the initial encounter should be one that fosters a bond of should be one that fosters a bond of trust and opens a line of communication trust and opens a line of communication among all participants. A professional among all participants. A professional and unhurried approach is mandatory, and unhurried approach is mandatory, with time taken to listen to concerns with time taken to listen to concerns and answer questions posed by the and answer questions posed by the patient and family members.patient and family members.

The surgeon's initial encounter with a The surgeon's initial encounter with a patient should result in the patient patient should result in the patient being able to express a basic being able to express a basic understanding of the disease process understanding of the disease process and the need for further investigation and the need for further investigation and possible surgical management. A and possible surgical management. A well-articulated follow-up plan is well-articulated follow-up plan is essential. essential.

Perioperative Decision Perioperative Decision MakingMaking

Once the decision has been made to Once the decision has been made to proceed with operative management, proceed with operative management, a number of considerations must be a number of considerations must be addressed regarding the timing and addressed regarding the timing and site of surgery, the type of site of surgery, the type of anesthesia, and the preoperative anesthesia, and the preoperative preparation necessary to understand preparation necessary to understand the patient's risk and optimize the the patient's risk and optimize the outcome. outcome.

These components of risk These components of risk assessment take into account both assessment take into account both the perioperative (intraoperative the perioperative (intraoperative period through 48 hours period through 48 hours postoperatively) and the later postoperatively) and the later postoperative (up to 30 days) periods postoperative (up to 30 days) periods and seek to identify factors that may and seek to identify factors that may contribute to patient morbidity contribute to patient morbidity during these periods. during these periods.

Preoperative EvaluationPreoperative Evaluation The aim of preoperative evaluation is The aim of preoperative evaluation is

not to screen broadly for not to screen broadly for undiagnosed disease but rather to undiagnosed disease but rather to identify and quantify any comorbidity identify and quantify any comorbidity that may have an impact on the that may have an impact on the operative outcome operative outcome

This evaluation is driven by findings on This evaluation is driven by findings on the history and physical examination the history and physical examination suggestive of organ system dysfunction suggestive of organ system dysfunction or by epidemiologic data suggesting or by epidemiologic data suggesting the benefit of evaluation based on age, the benefit of evaluation based on age, gender, or patterns of disease gender, or patterns of disease progression. The goal is to uncover progression. The goal is to uncover problem areas that may require further problem areas that may require further investigation or be amenable to investigation or be amenable to preoperative optimization preoperative optimization

Routine preoperative testing is not Routine preoperative testing is not cost-effective and, even in the cost-effective and, even in the elderly, is less predictive of elderly, is less predictive of perioperative morbidity than the perioperative morbidity than the American Society of American Society of Anesthesiologists (ASA) status or Anesthesiologists (ASA) status or American Heart Association American Heart Association

The preoperative evaluation is The preoperative evaluation is determined in light of the planned determined in light of the planned procedure (low, medium, or high procedure (low, medium, or high risk), the planned anesthetic risk), the planned anesthetic technique, and the postoperative technique, and the postoperative disposition of the patient (outpatient disposition of the patient (outpatient or inpatient, ward bed, or intensive or inpatient, ward bed, or intensive care care

In addition, the preoperative In addition, the preoperative evaluation is used to identify patient evaluation is used to identify patient risk factors for postoperative risk factors for postoperative morbidity and mortality. morbidity and mortality.

If preoperative evaluation uncovers If preoperative evaluation uncovers significant comorbidity or evidence of significant comorbidity or evidence of poor control of an underlying disease poor control of an underlying disease process, consultation with an internist process, consultation with an internist or medical subspecialist may be or medical subspecialist may be required to facilitate the workup and required to facilitate the workup and direct management. In this process, direct management. In this process, communication between the surgeon communication between the surgeon and consultants is essential to define and consultants is essential to define realistic goals for this optimization realistic goals for this optimization process and to expedite surgical process and to expedite surgical management management

SYSTEMS APPROACH TO SYSTEMS APPROACH TO PREOPERATIVE PREOPERATIVE EVALUATION EVALUATION

CardiovascularCardiovascular Cardiovascular disease is the leading Cardiovascular disease is the leading

cause of death in the industrialized cause of death in the industrialized world, and its contribution to world, and its contribution to perioperative mortality during perioperative mortality during noncardiac surgery is significant. Of noncardiac surgery is significant. Of the 27 million patients undergoing the 27 million patients undergoing surgery in the United States every surgery in the United States every year, 8 million, or nearly 30%, have year, 8 million, or nearly 30%, have significant coronary artery disease or significant coronary artery disease or other cardiac comorbid conditions. other cardiac comorbid conditions.

One million of these patients will One million of these patients will experience perioperative cardiac experience perioperative cardiac complications, with substantial complications, with substantial morbidity, mortality, and cost. morbidity, mortality, and cost. Consequently, much of the Consequently, much of the preoperative risk assessment and preoperative risk assessment and patient preparation centers on the patient preparation centers on the cardiovascular system. cardiovascular system.

One of the first anesthesia risk categorization One of the first anesthesia risk categorization systems was the ASA classification. It has systems was the ASA classification. It has five stratifications:five stratifications:

  I—Normal healthy patient  I—Normal healthy patient    II—Patient with mild systemic disease   II—Patient with mild systemic disease   III—Patient with severe systemic disease that III—Patient with severe systemic disease that

limits activity but is not incapacitating  limits activity but is not incapacitating  IV—Patient who has incapacitating disease that IV—Patient who has incapacitating disease that

is a constant threat to life is a constant threat to life   V—Moribund patient not expected to survive V—Moribund patient not expected to survive

24 hours with or without an operation 24 hours with or without an operation

There are more other systems for There are more other systems for evaluation of cardiovascular risk such evaluation of cardiovascular risk such as:as:

Goldman cardiac risk index,1977Goldman cardiac risk index,1977Detsky modified multifactorial index 1986Detsky modified multifactorial index 1986Eagle's Criteria for Cardiac Risk Eagle's Criteria for Cardiac Risk

Assessment, 1989 Assessment, 1989 Revised Cardiac Risk Index Revised Cardiac Risk Index

Once these data have been obtained, Once these data have been obtained, the surgeon and consultants need to the surgeon and consultants need to weigh the benefits of surgery against weigh the benefits of surgery against the risk and determine whether any the risk and determine whether any perioperative intervention will reduce perioperative intervention will reduce the probability of a cardiac event the probability of a cardiac event

This intervention usually centers on This intervention usually centers on coronary revascularization via coronary revascularization via coronary artery bypass or coronary artery bypass or percutaneous transluminal coronary percutaneous transluminal coronary angioplasty but may include angioplasty but may include modification of the choice of modification of the choice of anesthetic or the use of invasive anesthetic or the use of invasive intraoperative monitoring intraoperative monitoring

Patients who have undergone a Patients who have undergone a percutaneous coronary intervention percutaneous coronary intervention with stenting need to have elective with stenting need to have elective noncardiac procedures delayed for 4 noncardiac procedures delayed for 4 to 6 weeks, although the delay may to 6 weeks, although the delay may be shortened depending on the type be shortened depending on the type of stent used (drug eluting versus of stent used (drug eluting versus non–drug eluting non–drug eluting

The optimal timing of a surgical The optimal timing of a surgical procedure after myocardial infarction procedure after myocardial infarction (MI) is dependent on the duration of (MI) is dependent on the duration of time since the event and assessment time since the event and assessment of the patient's risk for ischemia, of the patient's risk for ischemia, either by clinical symptoms or by either by clinical symptoms or by noninvasive study noninvasive study

Any patient can be evaluated as a Any patient can be evaluated as a surgical candidate after an acute MI surgical candidate after an acute MI (within 7 days of evaluation) or a (within 7 days of evaluation) or a recent MI (within 7-30 days of recent MI (within 7-30 days of evaluation). The infarction event is evaluation). The infarction event is considered a major clinical predictor considered a major clinical predictor in the context of ongoing risk for in the context of ongoing risk for ischemia ischemia

The risk for reinfarction is generally The risk for reinfarction is generally considered low in the absence of considered low in the absence of such demonstrated risk. General such demonstrated risk. General recommendations are to wait 4 to 6 recommendations are to wait 4 to 6 weeks after MI to perform elective weeks after MI to perform elective surgery surgery

Improvements in postoperative care Improvements in postoperative care have centered on decreasing the have centered on decreasing the adrenergic surge associated with adrenergic surge associated with surgery and halting platelet surgery and halting platelet activation and microvascular activation and microvascular thrombosis thrombosis

Perioperative risk for cardiovascular Perioperative risk for cardiovascular morbidity and mortality was morbidity and mortality was decreased by 67% and 55%, decreased by 67% and 55%, respectively, in ACC/AHA-defined respectively, in ACC/AHA-defined medium- to high-risk patients medium- to high-risk patients receiving β-blockers in the receiving β-blockers in the perioperative period versus those perioperative period versus those receiving placebo. receiving placebo.

Although the benefit was most noticeable Although the benefit was most noticeable in the 6 months after surgery, event-free in the 6 months after surgery, event-free survival was significantly better in the survival was significantly better in the group that received β-blockers up to 2 group that received β-blockers up to 2 years after surgery .The current AHA/ACC years after surgery .The current AHA/ACC recommendations are to start β-blocker recommendations are to start β-blocker therapy in medium- to high-risk patients therapy in medium- to high-risk patients undergoing major- to intermediate-risk undergoing major- to intermediate-risk surgery as early as possible surgery as early as possible preoperatively and titrate to a heart rate preoperatively and titrate to a heart rate of 60 beats per minute. The choice of of 60 beats per minute. The choice of agent and duration of therapy are still agent and duration of therapy are still being debated being debated

An easy, inexpensive method to An easy, inexpensive method to determine cardiopulmonary determine cardiopulmonary functional status for noncardiac functional status for noncardiac surgery is the patient's ability or surgery is the patient's ability or inability to climb two flights of stairs. inability to climb two flights of stairs. Two flights of stairs is needed Two flights of stairs is needed because it demands greater than 4 because it demands greater than 4 metabolic equivalents (METs). metabolic equivalents (METs).

In a review of all studies of stair In a review of all studies of stair climbing as preoperative assessment, climbing as preoperative assessment, prospective studies have shown it to prospective studies have shown it to be a good predictor of mortality be a good predictor of mortality associated with thoracic surgery. In associated with thoracic surgery. In major noncardiac surgery, an inability major noncardiac surgery, an inability to climb two flights of stairs is an to climb two flights of stairs is an independent predictor of perioperative independent predictor of perioperative morbidity, but not mortality. morbidity, but not mortality.

PulmonaryPulmonary Preoperative evaluation of Preoperative evaluation of

pulmonary function may be pulmonary function may be necessary for either thoracic or necessary for either thoracic or general surgical procedures. general surgical procedures.

Whereas extremity, neurologic, and Whereas extremity, neurologic, and lower abdominal surgical procedures lower abdominal surgical procedures have little effect on pulmonary have little effect on pulmonary function and do not routinely require function and do not routinely require pulmonary function studies, thoracic pulmonary function studies, thoracic and upper abdominal procedures can and upper abdominal procedures can decrease pulmonary function and decrease pulmonary function and predispose to pulmonary predispose to pulmonary complications complications

Accordingly, it is wise to consider Accordingly, it is wise to consider assessment of pulmonary function for assessment of pulmonary function for all lung resection cases, for thoracic all lung resection cases, for thoracic procedures requiring single-lung procedures requiring single-lung ventilation, and for major abdominal ventilation, and for major abdominal and thoracic cases in patients who are and thoracic cases in patients who are older than 60 years, have significant older than 60 years, have significant underlying medical disease, smoke, or underlying medical disease, smoke, or have overt pulmonary symptomatology have overt pulmonary symptomatology

Necessary tests include forced Necessary tests include forced expiratory volume in 1 second expiratory volume in 1 second (FEV1), forced vital capacity, and the (FEV1), forced vital capacity, and the diffusing capacity of carbon diffusing capacity of carbon monoxide monoxide

Adults with an FEV1 of less than 0.8 L/sec, Adults with an FEV1 of less than 0.8 L/sec, or 30% of predicted, have a high risk for or 30% of predicted, have a high risk for complications and postoperative complications and postoperative pulmonary insufficiency. Pulmonary pulmonary insufficiency. Pulmonary resections need to be planned so that the resections need to be planned so that the postoperative FEV1 is greater than 0.8 postoperative FEV1 is greater than 0.8 L/sec, or 30% of predicted. Such planning L/sec, or 30% of predicted. Such planning can be done with the aid of quantitative can be done with the aid of quantitative lung scans, which can indicate which lung scans, which can indicate which segments of the lung are functional segments of the lung are functional

Preoperative pulmonary assessment Preoperative pulmonary assessment determines not only factors that determines not only factors that confer increased risk but also confer increased risk but also potential targets to reduce the risk potential targets to reduce the risk for pulmonary complications for pulmonary complications

General factors that increase risk for General factors that increase risk for postoperative pulmonary postoperative pulmonary complications include increasing age, complications include increasing age, lower albumin level, weight loss, and lower albumin level, weight loss, and possibly obesity possibly obesity

Concurrent comorbid conditions such Concurrent comorbid conditions such as impaired sensorium, previous as impaired sensorium, previous stroke, congestive heart failure, stroke, congestive heart failure, acute renal failure, chronic steroid acute renal failure, chronic steroid use, and blood transfusion are also use, and blood transfusion are also associated with increased risk for associated with increased risk for postoperative pulmonary postoperative pulmonary complications complications

Specific pulmonary risk factors Specific pulmonary risk factors include chronic obstructive include chronic obstructive pulmonary disease, smoking, pulmonary disease, smoking, preoperative sputum production, preoperative sputum production, pneumonia, dyspnea, and pneumonia, dyspnea, and obstructive sleep apnea. obstructive sleep apnea.

Preoperative interventions that may Preoperative interventions that may decrease postoperative pulmonary decrease postoperative pulmonary complications include smoking cessation complications include smoking cessation (>2 months before the planned (>2 months before the planned procedure), bronchodilator therapy, procedure), bronchodilator therapy, antibiotic therapy for preexisting antibiotic therapy for preexisting infection, and pretreatment of asthmatic infection, and pretreatment of asthmatic patients with steroids. Perioperative patients with steroids. Perioperative strategies include the use of epidural strategies include the use of epidural anesthesia, vigorous pulmonary toilet and anesthesia, vigorous pulmonary toilet and rehabilitation, and continued rehabilitation, and continued bronchodilator therapy.bronchodilator therapy.

RenalRenalApproximately 5% of the adult Approximately 5% of the adult

population have some degree of population have some degree of renal dysfunction that can affect the renal dysfunction that can affect the physiology of multiple organ systems physiology of multiple organ systems and cause additional morbidity in the and cause additional morbidity in the perioperative period. In fact, a perioperative period. In fact, a preoperative creatinine level of 2.0 preoperative creatinine level of 2.0 mg/dL or higher is an independent mg/dL or higher is an independent risk factor for cardiac complications risk factor for cardiac complications

Identification of coexisting Identification of coexisting cardiovascular, circulatory, cardiovascular, circulatory, hematologic, and metabolic hematologic, and metabolic derangements secondary to renal derangements secondary to renal dysfunction are the goals of dysfunction are the goals of preoperative evaluation in these preoperative evaluation in these patients patients

A patient with known renal A patient with known renal insufficiency undergoes a thorough insufficiency undergoes a thorough history and physical examination with history and physical examination with particular questioning about previous particular questioning about previous MI and symptoms consistent with MI and symptoms consistent with ischemic heart disease. The ischemic heart disease. The cardiovascular examination seeks to cardiovascular examination seeks to document signs of fluid overload. The document signs of fluid overload. The patient's functional status and exercise patient's functional status and exercise tolerance are carefully elicited. tolerance are carefully elicited.

Diagnostic testing for patients with Diagnostic testing for patients with renal dysfunction include an renal dysfunction include an electrocardiogram (ECG), serum electrocardiogram (ECG), serum chemistry panel, and complete blood chemistry panel, and complete blood count (CBC). If physical examination count (CBC). If physical examination findings are suggestive of heart findings are suggestive of heart failure, a chest radiograph may be failure, a chest radiograph may be helpful helpful

Urinalysis and urinary electrolyte Urinalysis and urinary electrolyte studies are not often helpful in the studies are not often helpful in the setting of established renal setting of established renal insufficiency, although they may be insufficiency, although they may be diagnostic in patients with new-onset diagnostic in patients with new-onset renal dysfunction. renal dysfunction.

Laboratory abnormalities are often Laboratory abnormalities are often seen in a patient with advanced renal seen in a patient with advanced renal insufficiency. Some metabolic insufficiency. Some metabolic derangements in a patient with derangements in a patient with advanced renal failure may be mild advanced renal failure may be mild and asymptomatic and are revealed and asymptomatic and are revealed by electrolyte or blood gas analysis by electrolyte or blood gas analysis

Anemia, when present in these Anemia, when present in these patients, may range from mild and patients, may range from mild and asymptomatic to that associated with asymptomatic to that associated with fatigue, low exercise tolerance, and fatigue, low exercise tolerance, and exertional angina. Such anemia can exertional angina. Such anemia can be treated with erythropoietin or be treated with erythropoietin or darbepoietin preoperatively or darbepoietin preoperatively or perioperatively perioperatively

Because the platelet dysfunction Because the platelet dysfunction associated with uremia is often a associated with uremia is often a qualitative one, platelet counts are qualitative one, platelet counts are usually normal. A safe course is to usually normal. A safe course is to communicate with the communicate with the anesthesiologist the potential need anesthesiologist the potential need for agents to be available in the for agents to be available in the operating room to assist in improving operating room to assist in improving platelet function. platelet function.

Pharmacologic manipulation of Pharmacologic manipulation of hyperkalemia, replacement of hyperkalemia, replacement of calcium for symptomatic calcium for symptomatic hypocalcemia, and the use of hypocalcemia, and the use of phosphate-binding antacids for phosphate-binding antacids for hyperphosphatemia are often hyperphosphatemia are often required. required.

Sodium bicarbonate is used in the Sodium bicarbonate is used in the setting of metabolic acidosis not setting of metabolic acidosis not caused by hypoperfusion when caused by hypoperfusion when serum bicarbonate levels are below serum bicarbonate levels are below 15 mEq/L. It can be administered in 15 mEq/L. It can be administered in intravenous (IV) fluid as 1 to 2 intravenous (IV) fluid as 1 to 2 ampules in a 5% dextrose solution ampules in a 5% dextrose solution

Hyponatremia is treated by volume Hyponatremia is treated by volume restriction, although dialysis is restriction, although dialysis is commonly required within the commonly required within the perioperative period for control of perioperative period for control of volume and electrolyte abnormalities volume and electrolyte abnormalities

Patients with chronic end-stage renal Patients with chronic end-stage renal disease undergo dialysis before disease undergo dialysis before surgery to optimize their volume surgery to optimize their volume status and control the potassium status and control the potassium level. Intraoperative hyperkalemia level. Intraoperative hyperkalemia can result from surgical manipulation can result from surgical manipulation of tissue or transfusion of blood. of tissue or transfusion of blood. Such patients are often dialyzed on Such patients are often dialyzed on the day after surgery as well the day after surgery as well

Prevention of secondary renal insults in Prevention of secondary renal insults in the perioperative period include the the perioperative period include the avoidance of nephrotoxic agents and avoidance of nephrotoxic agents and maintenance of adequate intravascular maintenance of adequate intravascular volume throughout this period. In the volume throughout this period. In the postoperative period, the postoperative period, the pharmacokinetics of many drugs may be pharmacokinetics of many drugs may be unpredictable, and adjustments in dosage unpredictable, and adjustments in dosage need to be made according to pharmacy need to be made according to pharmacy recommendation. recommendation.

In the acute setting, patients who In the acute setting, patients who have stable volume status can have stable volume status can undergo surgery without undergo surgery without preoperative dialysis, provided that preoperative dialysis, provided that no other indication exists for no other indication exists for emergency dialysis. emergency dialysis.

Notably, narcotics used for Notably, narcotics used for postoperative pain control may have postoperative pain control may have prolonged effects despite hepatic prolonged effects despite hepatic clearance, and nonsteroidal agents clearance, and nonsteroidal agents are avoided in patients with renal are avoided in patients with renal insufficiency. insufficiency.

Principles of Principles of Preoperative and Preoperative and

Operative Surgery Operative Surgery Prof. Med. Nabil H. MohyeddinProf. Med. Nabil H. Mohyeddin

Anaesthesiologist & IntensivistAnaesthesiologist & IntensivistGermany, Rostock universityGermany, Rostock university

SYSTEMS APPROACH TO SYSTEMS APPROACH TO PREOPERATIVE PREOPERATIVE EVALUATION EVALUATION

Hepatobiliary Hepatobiliary Hepatic dysfunction may reflect the Hepatic dysfunction may reflect the

common pathway of a number of common pathway of a number of insults to the liver, including viral-, insults to the liver, including viral-, drug-, and toxin-mediated disease. A drug-, and toxin-mediated disease. A patient with liver dysfunction requires patient with liver dysfunction requires careful assessment of the degree of careful assessment of the degree of functional impairment, as well as a functional impairment, as well as a coordinated effort to avoid additional coordinated effort to avoid additional insult in the perioperative period insult in the perioperative period

A history of any exposure to blood A history of any exposure to blood and blood products or exposure to and blood products or exposure to hepatotoxic agents is obtained. hepatotoxic agents is obtained. Patients frequently know whether Patients frequently know whether hepatitis has been diagnosed and hepatitis has been diagnosed and need to be questioned about when need to be questioned about when the diagnosis was made and what the diagnosis was made and what activity led to the infection activity led to the infection

Although such a history may not Although such a history may not affect further patient evaluation, it is affect further patient evaluation, it is important to obtain in case an important to obtain in case an operative team member is injured operative team member is injured during the planned surgical during the planned surgical procedure. procedure.

A review of systems specifically A review of systems specifically inquires about symptoms such as inquires about symptoms such as pruritus, fatigability, excessive pruritus, fatigability, excessive bleeding, abdominal distention, and bleeding, abdominal distention, and weight gain. Evidence of hepatic weight gain. Evidence of hepatic dysfunction may be seen on physical dysfunction may be seen on physical examination examination

Jaundice and scleral icterus may be Jaundice and scleral icterus may be evident with serum bilirubin levels evident with serum bilirubin levels higher than 3 mg/dL. Skin changes higher than 3 mg/dL. Skin changes include spider angiomas, caput include spider angiomas, caput medusae, palmar erythema, and medusae, palmar erythema, and clubbing of the fingertips. Abdominal clubbing of the fingertips. Abdominal examination may reveal distention, examination may reveal distention, evidence of fluid shift, and evidence of fluid shift, and hepatomegaly. Encephalopathy or hepatomegaly. Encephalopathy or asterixis may be evident. Muscle asterixis may be evident. Muscle wasting or cachexia can be wasting or cachexia can be prominent prominent

A patient with liver dysfunction A patient with liver dysfunction undergoes standard liver function undergoes standard liver function tests. Elevations in hepatocellular tests. Elevations in hepatocellular enzymes may suggest a diagnosis of enzymes may suggest a diagnosis of acute or chronic hepatitis, which can acute or chronic hepatitis, which can be investigated by serologic testing be investigated by serologic testing for hepatitis A, B, and C. Alcoholic for hepatitis A, B, and C. Alcoholic hepatitis is suggested by lower hepatitis is suggested by lower transaminase levels and an transaminase levels and an aspartate/alanine transaminase ratio aspartate/alanine transaminase ratio (AST/ALT) greater than 2 (AST/ALT) greater than 2

Laboratory evidence of chronic Laboratory evidence of chronic hepatitis or clinical findings hepatitis or clinical findings consistent with cirrhosis is consistent with cirrhosis is investigated with tests of hepatic investigated with tests of hepatic synthetic function, notably serum synthetic function, notably serum albumin, prothrombin, and fibrinogen albumin, prothrombin, and fibrinogen

Patients with evidence of impaired Patients with evidence of impaired hepatic synthetic function also have hepatic synthetic function also have a CBC and serum electrolyte a CBC and serum electrolyte analysis. Type and screen is analysis. Type and screen is indicated for any procedure in which indicated for any procedure in which blood loss could be more than blood loss could be more than minimal. minimal.

In the event of an emergency In the event of an emergency situation requiring surgery, such an situation requiring surgery, such an investigation may not be possible. A investigation may not be possible. A patient with acute hepatitis and patient with acute hepatitis and elevated transaminases is managed elevated transaminases is managed nonoperatively, when feasible, until nonoperatively, when feasible, until several weeks beyond normalization several weeks beyond normalization of laboratory values. of laboratory values.

Urgent or emergency procedures in Urgent or emergency procedures in these patients are associated with these patients are associated with increased morbidity and mortality. A increased morbidity and mortality. A patient with evidence of chronic patient with evidence of chronic hepatitis may often safely undergo hepatitis may often safely undergo surgery surgery

A patient with cirrhosis may be A patient with cirrhosis may be assessed with the Child-Pugh assessed with the Child-Pugh classification, which stratifies classification, which stratifies operative risk according to a score operative risk according to a score based on abnormal albumin and based on abnormal albumin and bilirubin levels, prolongation of the bilirubin levels, prolongation of the prothrombin time (PT), and the prothrombin time (PT), and the degree of ascites and degree of ascites and encephalopathy encephalopathy

This scoring system was initially This scoring system was initially applied to predict mortality in applied to predict mortality in cirrhotic patients undergoing cirrhotic patients undergoing portacaval shunt procedures, portacaval shunt procedures, although it has been shown to although it has been shown to correlate with mortality in cirrhotic correlate with mortality in cirrhotic patients undergoing a wider patients undergoing a wider spectrum of procedures as well. spectrum of procedures as well.

Although the figures may not Although the figures may not represent current risk for all types of represent current risk for all types of abdominal operations, little doubt abdominal operations, little doubt exists that the presence of cirrhosis exists that the presence of cirrhosis confers additional risk for abdominal confers additional risk for abdominal surgery and that this risk is surgery and that this risk is proportional to the severity of proportional to the severity of disease disease

Other factors that affect outcomes in Other factors that affect outcomes in these patients are the emergency these patients are the emergency nature of a procedure, prolongation nature of a procedure, prolongation of the PT greater than 3 seconds of the PT greater than 3 seconds above normal and refractory to above normal and refractory to correction with vitamin K, and the correction with vitamin K, and the presence of infection presence of infection

Two common problems requiring Two common problems requiring surgical evaluation in a cirrhotic surgical evaluation in a cirrhotic patient are hernia (umbilical and patient are hernia (umbilical and groin) and cholecystitis. An umbilical groin) and cholecystitis. An umbilical hernia in the presence of ascites is a hernia in the presence of ascites is a difficult management problem difficult management problem because spontaneous rupture is because spontaneous rupture is associated with increased mortality associated with increased mortality rates.rates.

Elective repair is best after the Elective repair is best after the ascites has been reduced to a ascites has been reduced to a minimum preoperatively, although minimum preoperatively, although the procedure is still associated with the procedure is still associated with mortality rates as high as 14%.Repair mortality rates as high as 14%.Repair of groin hernias in the presence of of groin hernias in the presence of ascites is less risky in terms of both ascites is less risky in terms of both recurrence and mortality.recurrence and mortality.

Several recent reports have shown Several recent reports have shown decreased rates of complication with decreased rates of complication with laparoscopic procedures performed in laparoscopic procedures performed in cirrhotic patients. Among the best-cirrhotic patients. Among the best-described procedures is laparoscopic described procedures is laparoscopic cholecystectomy performed in patients cholecystectomy performed in patients with Child's class A through C. When with Child's class A through C. When compared with open cholecystectomy, compared with open cholecystectomy, less morbidity in terms of blood loss and less morbidity in terms of blood loss and wound infection has been observed.wound infection has been observed.

Malnutrition is common in cirrhotic Malnutrition is common in cirrhotic patients and is associated with a patients and is associated with a reduction in hepatic glycogen stores reduction in hepatic glycogen stores and reduced hepatic protein synthesis. and reduced hepatic protein synthesis. Patients with advanced liver disease Patients with advanced liver disease often have a poor appetite, tense often have a poor appetite, tense ascites, and abdominal pain. Attention ascites, and abdominal pain. Attention must be given to appropriate enteral must be given to appropriate enteral supplementation, as done for all supplementation, as done for all patients at significant nutritional risk.patients at significant nutritional risk.

EndocrineEndocrine A patient with an endocrine condition A patient with an endocrine condition

such as diabetes mellitus, such as diabetes mellitus, hyperthyroidism or hypothyroidism, hyperthyroidism or hypothyroidism, or adrenal insufficiency is subject to or adrenal insufficiency is subject to additional physiologic stress during additional physiologic stress during surgery. surgery.

The preoperative evaluation The preoperative evaluation identifies the type and degree of identifies the type and degree of endocrine dysfunction to permit endocrine dysfunction to permit preoperative optimization. Careful preoperative optimization. Careful monitoring identifies signs of monitoring identifies signs of metabolic stress related to metabolic stress related to inadequate endocrine control during inadequate endocrine control during surgery and throughout the surgery and throughout the postoperative course.postoperative course.

The evaluation of a diabetic patient The evaluation of a diabetic patient for surgery assesses the adequacy of for surgery assesses the adequacy of glycemic control and identifies the glycemic control and identifies the presence of diabetic complications, presence of diabetic complications, which may have an impact on the which may have an impact on the patient's perioperative course. patient's perioperative course.

The patient's history and physical The patient's history and physical examination document evidence of examination document evidence of diabetic complications, including diabetic complications, including cardiac disease, circulatory cardiac disease, circulatory abnormalities, and the presence of abnormalities, and the presence of retinopathy, neuropathy, or retinopathy, neuropathy, or nephropathy nephropathy

Preoperative testing may include Preoperative testing may include fasting and postprandial glucose and fasting and postprandial glucose and hemoglobin A1c levels. Serum hemoglobin A1c levels. Serum electrolyte, blood urea nitrogen, and electrolyte, blood urea nitrogen, and creatinine levels are obtained to creatinine levels are obtained to identify metabolic disturbances and identify metabolic disturbances and renal involvement. Urinalysis may renal involvement. Urinalysis may reveal proteinuria as evidence of reveal proteinuria as evidence of diabetic nephropathy. diabetic nephropathy.

An ECG is considered in patients with An ECG is considered in patients with long-standing disease. The existence long-standing disease. The existence of neuropathy in diabetics may be of neuropathy in diabetics may be accompanied by cardiac autonomic accompanied by cardiac autonomic neuropathy, which increases the risk neuropathy, which increases the risk for cardiorespiratory instability in the for cardiorespiratory instability in the perioperative period. perioperative period.

A diabetic patient requires special A diabetic patient requires special attention to optimize glycemic attention to optimize glycemic control perioperatively. Non–insulin-control perioperatively. Non–insulin-dependent diabetics need to dependent diabetics need to discontinue long-acting sulfonylureas discontinue long-acting sulfonylureas such as chlorpropamide and such as chlorpropamide and glyburide because of the risk for glyburide because of the risk for intraoperative hypoglycemia; a intraoperative hypoglycemia; a shorter-acting agent or sliding-scale shorter-acting agent or sliding-scale insulin coverage may be substituted insulin coverage may be substituted in this period. in this period.

The use of metformin is stopped The use of metformin is stopped preoperatively because of its preoperatively because of its association with lacticacidosis in the association with lacticacidosis in the setting of renal insufficiency. An setting of renal insufficiency. An insulin-dependent diabetic is told to insulin-dependent diabetic is told to withhold long-acting insulin withhold long-acting insulin preparations (Ultralente preparations (Ultralente preparations) on the day of surgery; preparations) on the day of surgery; lower dosages of intermediate-acting lower dosages of intermediate-acting insulin (NPH or Lente) are substituted insulin (NPH or Lente) are substituted on the morning of surgery on the morning of surgery

These patients are scheduled for These patients are scheduled for early morning surgery, when early morning surgery, when feasible. During surgery, a standard feasible. During surgery, a standard 5% or 10% dextrose infusion is used 5% or 10% dextrose infusion is used with short-acting insulin or an insulin with short-acting insulin or an insulin drip to maintain glycemic control drip to maintain glycemic control

A patient with diabetes mellitus that A patient with diabetes mellitus that is well controlled by diet or oral is well controlled by diet or oral medication may not require insulin medication may not require insulin perioperatively, but those with perioperatively, but those with poorer control or patients taking poorer control or patients taking insulin may require preoperative insulin may require preoperative dosing and both glucose and insulin dosing and both glucose and insulin infusion during surgery infusion during surgery

Frequent assessments of glucose Frequent assessments of glucose levels are continued through the levels are continued through the postoperative period. Current postoperative period. Current recommendations are to maintain recommendations are to maintain the perioperative glucose level the perioperative glucose level between 80 and 150 mg/dL, even in between 80 and 150 mg/dL, even in patients not previously diagnosed as patients not previously diagnosed as being diabetic. Adequate hydration being diabetic. Adequate hydration must be maintained with avoidance must be maintained with avoidance of hypovolemia. of hypovolemia.

Postoperative orders include frequent Postoperative orders include frequent (every 2-4 hours) finger stick glucose (every 2-4 hours) finger stick glucose checks and the use of short-acting checks and the use of short-acting insulin in the form of sliding-scale insulin in the form of sliding-scale coverage. Twice-daily doses of coverage. Twice-daily doses of intermediate-acting insulin can be intermediate-acting insulin can be supplemented with sliding-scale supplemented with sliding-scale coverage until the patient is eating coverage until the patient is eating and can resume the usual regimen and can resume the usual regimen

Postoperative cardiac events can Postoperative cardiac events can occur with unusual manifestations in occur with unusual manifestations in these patients. Although chest pain these patients. Although chest pain needs to be evaluated with ECG and needs to be evaluated with ECG and serum troponin levels, this same serum troponin levels, this same evaluation may need to be done for evaluation may need to be done for new-onset dyspnea, blood pressure new-onset dyspnea, blood pressure alterations, or a decrease in urine alterations, or a decrease in urine output output

Adequate prophylaxis for deep Adequate prophylaxis for deep venous thrombosis (DVT) is essential venous thrombosis (DVT) is essential because of the increased risk for because of the increased risk for thrombosis. The adequacy of thrombosis. The adequacy of perioperative glycemic control has perioperative glycemic control has an impact on wound healing and the an impact on wound healing and the risk for surgical site infection risk for surgical site infection

Perioperative Diabetic Perioperative Diabetic Management Management

Management of diabetic patients has Management of diabetic patients has evolved over the past several years. evolved over the past several years. The introduction of new drugs for non–The introduction of new drugs for non–insulin-dependent diabetics, in addition insulin-dependent diabetics, in addition to new types of insulin and new insulin to new types of insulin and new insulin delivery systems in insulin-dependent delivery systems in insulin-dependent diabetics, has changed the way that diabetics, has changed the way that these patients are approached in the these patients are approached in the perioperative period.perioperative period.

Rapid-acting (Lispro) and short-Rapid-acting (Lispro) and short-acting (Regular) insulin preparations acting (Regular) insulin preparations are usually withheld when the are usually withheld when the patient stops oral intake (NPO) and patient stops oral intake (NPO) and are used for acute management of are used for acute management of hyperglycemia during the NPO period hyperglycemia during the NPO period

intermediate-acting (NPH Lente) and long-intermediate-acting (NPH Lente) and long-acting (Ultralente, Glargine) insulin acting (Ultralente, Glargine) insulin preparations are administered at two preparations are administered at two thirds the normal pm dose the night thirds the normal pm dose the night before surgery and half the normal am before surgery and half the normal am dose the morning of surgery, with frequent dose the morning of surgery, with frequent bedside glucose determinations and bedside glucose determinations and treatment with short-acting insulin as treatment with short-acting insulin as needed. An infusion of 5% dextrose is needed. An infusion of 5% dextrose is initiated the morning of surgery initiated the morning of surgery

If the planned procedure is expected If the planned procedure is expected to take a long time, an insulin to take a long time, an insulin infusion can be administered, again infusion can be administered, again with frequent monitoring of blood with frequent monitoring of blood glucose. glucose.

Insulin pumps are used by some Insulin pumps are used by some patients as their method of glucose patients as their method of glucose management. These pumps use management. These pumps use short-acting insulin and have a short-acting insulin and have a variable delivery rate that can be variable delivery rate that can be programmed to more closely programmed to more closely simulate endogenous insulin simulate endogenous insulin productionproduction

On the day of surgery, the patient On the day of surgery, the patient continues with the basal insulin continues with the basal insulin infusion. The pump is then used to infusion. The pump is then used to correct the glucose level as it is correct the glucose level as it is measured. Patients generally have a measured. Patients generally have a correction or sensitivity factor that correction or sensitivity factor that will decrease their glucose by 50 will decrease their glucose by 50 mg/dL. It is important to know this mg/dL. It is important to know this factor before the planned surgical factor before the planned surgical procedure so that glucose can be procedure so that glucose can be managed in the operating room managed in the operating room

Patients who take oral hypoglycemic Patients who take oral hypoglycemic agents typically withhold their normal agents typically withhold their normal dose the day of surgery. Patients can dose the day of surgery. Patients can resume their oral agent once diet is resume their oral agent once diet is resumed. Coverage for hyperglycemia is resumed. Coverage for hyperglycemia is with a short-acting insulin preparation with a short-acting insulin preparation based on blood glucose monitoring. An based on blood glucose monitoring. An exception is metformin. If the patient has exception is metformin. If the patient has altered renal function, this agent needs to altered renal function, this agent needs to be discontinued until renal function either be discontinued until renal function either normalizes or stabilizes.normalizes or stabilizes.

patient with known or suspected patient with known or suspected thyroid disease is evaluated with a thyroid disease is evaluated with a thyroid function panel. Evidence of thyroid function panel. Evidence of hyperthyroidism is addressed hyperthyroidism is addressed preoperatively and surgery deferred preoperatively and surgery deferred until a euthyroid state is achieved, until a euthyroid state is achieved, when feasible when feasible

These patients need to have their These patients need to have their electrolyte levels determined and an electrolyte levels determined and an ECG performed as part of their ECG performed as part of their preoperative evaluation. In addition, preoperative evaluation. In addition, if the physical examination suggests if the physical examination suggests signs of airway compromise, further signs of airway compromise, further imaging may be warranted imaging may be warranted

A patient with hyperthyroidism who A patient with hyperthyroidism who takes antithyroid medication such as takes antithyroid medication such as propylthiouracil or methimazole is propylthiouracil or methimazole is instructed to continue this regimen instructed to continue this regimen on the day of surgery on the day of surgery

The patient's usual doses of β-The patient's usual doses of β-blockers or digoxin are also blockers or digoxin are also continued. In the event of urgent continued. In the event of urgent surgery in a thyrotoxic patient at risk surgery in a thyrotoxic patient at risk for thyroid storm, a combination of for thyroid storm, a combination of adrenergic blockers and adrenergic blockers and glucocorticoids may be required and glucocorticoids may be required and are administered in consultation with are administered in consultation with an endocrinologist an endocrinologist

Patients with newly diagnosed Patients with newly diagnosed hypothyroidism generally do not hypothyroidism generally do not require preoperative treatment, require preoperative treatment, although they may be subject to although they may be subject to increased sensitivity to medications, increased sensitivity to medications, including anesthetic agents and including anesthetic agents and narcotics narcotics

Severe hypothyroidism can be Severe hypothyroidism can be associated with myocardial associated with myocardial dysfunction, coagulation dysfunction, coagulation abnormality, and electrolyte abnormality, and electrolyte imbalance, notably hypoglycemia. imbalance, notably hypoglycemia. Severe hypothyroidism needs to be Severe hypothyroidism needs to be corrected before elective operations corrected before elective operations

HematologicHematologic Hematologic assessment may lead to Hematologic assessment may lead to

the identification of disorders such as the identification of disorders such as anemia, inherited or acquired anemia, inherited or acquired coagulopathy, or a hypercoagulable coagulopathy, or a hypercoagulable state. Substantial morbidity may derive state. Substantial morbidity may derive from failure to identify these from failure to identify these abnormalities preoperatively. The need abnormalities preoperatively. The need for perioperative prophylaxis for venous for perioperative prophylaxis for venous thromboembolism must be carefully thromboembolism must be carefully reviewed in every surgical patient.reviewed in every surgical patient.

Anemia is the most common Anemia is the most common laboratory abnormality encountered laboratory abnormality encountered in preoperative patients. It is often in preoperative patients. It is often asymptomatic and can require further asymptomatic and can require further investigation to understand its cause. investigation to understand its cause. The history and physical examination The history and physical examination may uncover subjective complaints of may uncover subjective complaints of energy loss, dyspnea, or palpitations, energy loss, dyspnea, or palpitations, and pallor or cyanosis may be evident and pallor or cyanosis may be evident

Patients are evaluated for Patients are evaluated for lymphadenopathy, hepatomegaly, or lymphadenopathy, hepatomegaly, or splenomegaly, and pelvic and rectal splenomegaly, and pelvic and rectal examinations are performed. A CBC, examinations are performed. A CBC, reticulocyte count, and serum iron, reticulocyte count, and serum iron, total iron-binding capacity, ferritin, total iron-binding capacity, ferritin, vitamin B12, and folate levels are vitamin B12, and folate levels are obtained to investigate the cause of obtained to investigate the cause of anemia. anemia.

The decision to transfuse a patient The decision to transfuse a patient perioperatively is made with perioperatively is made with consideration of the patient's consideration of the patient's underlying risk factors for ischemic underlying risk factors for ischemic heart disease and the estimated heart disease and the estimated magnitude of blood loss during magnitude of blood loss during surgery. surgery.

Generally, patients with Generally, patients with normovolemic anemia without normovolemic anemia without significant cardiac risk or anticipated significant cardiac risk or anticipated blood loss can be managed safely blood loss can be managed safely without transfusion, with most without transfusion, with most healthy patients tolerating healthy patients tolerating hemoglobin levels of 6 or 7 g/dL hemoglobin levels of 6 or 7 g/dL

Guidelines for Red Blood Cell Guidelines for Red Blood Cell Transfusion for Acute Blood Transfusion for Acute Blood

Loss Loss Evaluate the risk for ischemia Evaluate the risk for ischemia Estimate/anticipate the degree of Estimate/anticipate the degree of

blood loss. Less than 30% rapid blood loss. Less than 30% rapid volume loss probably does not volume loss probably does not require transfusion in a previously require transfusion in a previously healthy individual healthy individual

Measure the hemoglobin Measure the hemoglobin concentration: <6 g/dL, transfusion concentration: <6 g/dL, transfusion usually required; 6-10 g/dL, usually required; 6-10 g/dL, transfusion dictated by clinical transfusion dictated by clinical circumstance; >10 g/dL, transfusion circumstance; >10 g/dL, transfusion rarely required rarely required

Measure vital signs/tissue Measure vital signs/tissue oxygenation when hemoglobin is 6-oxygenation when hemoglobin is 6-10 g/dL and the extent of blood loss 10 g/dL and the extent of blood loss is unknown. Tachycardia and is unknown. Tachycardia and hypotension refractory to volume hypotension refractory to volume suggest the need for transfusion; O2 suggest the need for transfusion; O2 extraction ratio >50%, decreased extraction ratio >50%, decreased Vo2, suggest that transfusion is Vo2, suggest that transfusion is usually needed usually needed

All patients undergoing surgery are All patients undergoing surgery are questioned to assess their bleeding questioned to assess their bleeding risk. Coagulopathy may result from risk. Coagulopathy may result from inherited or acquired platelet or inherited or acquired platelet or factor disorders or may be factor disorders or may be associated with organ dysfunction or associated with organ dysfunction or medications medications

The inquiry begins with direct The inquiry begins with direct questioning about a personal or questioning about a personal or family history of abnormal bleeding. family history of abnormal bleeding. Supporting information includes a Supporting information includes a history of easy bruising or abnormal history of easy bruising or abnormal bleeding associated with minor bleeding associated with minor procedures or injury. procedures or injury.

A history of liver or kidney dysfunction A history of liver or kidney dysfunction or recent common bile duct obstruction or recent common bile duct obstruction needs to be elicited, as well as an needs to be elicited, as well as an assessment of nutritional status. assessment of nutritional status. Medications are carefully reviewed, and Medications are carefully reviewed, and the use of anticoagulants, salicylates, the use of anticoagulants, salicylates, nonsteroidal anti-inflammatory drugs nonsteroidal anti-inflammatory drugs (NSAIDs), and antiplatelet drugs are (NSAIDs), and antiplatelet drugs are noted noted

Physical examination may reveal Physical examination may reveal bruising, petechiae, or signs of liver bruising, petechiae, or signs of liver dysfunction. dysfunction.

Patients with thrombocytopenia may Patients with thrombocytopenia may have qualitative or quantitative have qualitative or quantitative defects as a result of immune-related defects as a result of immune-related disease, infection, drugs, or liver or disease, infection, drugs, or liver or kidney dysfunction. kidney dysfunction.

Qualitative defects may respond to Qualitative defects may respond to medical management of the medical management of the underlying disease process, whereas underlying disease process, whereas quantitative defects may require quantitative defects may require platelet transfusion when counts are platelet transfusion when counts are less than 50,000 in a patient at risk less than 50,000 in a patient at risk for bleeding for bleeding

Although coagulation studies are not Although coagulation studies are not routinely ordered, patients with a routinely ordered, patients with a history suggestive of coagulopathy history suggestive of coagulopathy undergo coagulation studies before undergo coagulation studies before surgery. Coagulation studies are also surgery. Coagulation studies are also obtained before the procedure if obtained before the procedure if considerable bleeding is anticipated considerable bleeding is anticipated or any significant bleeding would be or any significant bleeding would be catastrophic. catastrophic.

Patients with documented disorders Patients with documented disorders of coagulation may require of coagulation may require perioperative management of factor perioperative management of factor deficiencies, often in consultation deficiencies, often in consultation with a hematologistwith a hematologist

Patients receiving anticoagulation Patients receiving anticoagulation therapy usually require preoperative therapy usually require preoperative reversal of the anticoagulant effect. reversal of the anticoagulant effect. In patients taking warfarin, the drug In patients taking warfarin, the drug is withheld for four scheduled doses is withheld for four scheduled doses preoperatively to allow the preoperatively to allow the international normalized ratio (INR) international normalized ratio (INR) to fall to the range of 1.5 or less to fall to the range of 1.5 or less (assuming that the patient is (assuming that the patient is maintained at an INR of 2.0-3.0). maintained at an INR of 2.0-3.0).

Additional recommendations for Additional recommendations for specific diagnoses requiring chronic specific diagnoses requiring chronic anticoagulation are based on risk-anticoagulation are based on risk-benefit analysis. Patients with a recent benefit analysis. Patients with a recent history of venous thromboembolism or history of venous thromboembolism or acute arterial embolism frequently acute arterial embolism frequently require perioperative IV heparinization require perioperative IV heparinization because of an increased risk for because of an increased risk for recurrent events in the perioperative recurrent events in the perioperative period period

Systemic heparinization can often be Systemic heparinization can often be stopped within 6 hours of surgery and stopped within 6 hours of surgery and restarted within 12 hours restarted within 12 hours postoperatively. When possible, postoperatively. When possible, surgery is postponed in the first surgery is postponed in the first month after an episode of venous or month after an episode of venous or arterial thromboembolism. Patients arterial thromboembolism. Patients taking anticoagulants for less than 2 taking anticoagulants for less than 2 weeks for pulmonary embolism (PE) weeks for pulmonary embolism (PE) or proximal DVT are considered for or proximal DVT are considered for inferior vena cava filter placement inferior vena cava filter placement before surgery before surgery

All surgical patients are assessed for All surgical patients are assessed for their risk for venous their risk for venous thromboembolism and receive thromboembolism and receive adequate prophylaxis according to adequate prophylaxis according to current guidelines.Patients are current guidelines.Patients are questioned to elicit any personal or questioned to elicit any personal or family history suggestive of a family history suggestive of a hypercoagulable state. hypercoagulable state. Levels of Levels of protein C, protein S, antithrombin III, protein C, protein S, antithrombin III, and antiphospholipid antibody can be and antiphospholipid antibody can be obtained obtained

Risk factor stratification is achieved by Risk factor stratification is achieved by considering multiple factors, including considering multiple factors, including age, type of surgical procedure, age, type of surgical procedure, previous thromboembolism, cancer, previous thromboembolism, cancer, obesity, varicose veins, cardiac obesity, varicose veins, cardiac dysfunction, indwelling central venous dysfunction, indwelling central venous catheters, inflammatory bowel disease, catheters, inflammatory bowel disease, nephrotic syndrome, pregnancy, and nephrotic syndrome, pregnancy, and estrogen or tamoxifen use. estrogen or tamoxifen use.

A number of regimens may be A number of regimens may be appropriate for prophylaxis of venous appropriate for prophylaxis of venous thromboembolism, depending on thromboembolism, depending on assessed risk.Such regimens include assessed risk.Such regimens include the use of unfractionated heparin, the use of unfractionated heparin, low-molecular-weight heparin, low-molecular-weight heparin, intermittent compression devices, intermittent compression devices, and early ambulation. Initial and early ambulation. Initial prophylactic doses of heparin can be prophylactic doses of heparin can be given preoperatively, within 2 hours given preoperatively, within 2 hours of surgery.of surgery.

ADDITIONAL PREOPERATIVE ADDITIONAL PREOPERATIVE CONSIDERATIONS CONSIDERATIONS

Older adults account for a Older adults account for a disproportionate percentage of disproportionate percentage of surgical patients. Risk assessment surgical patients. Risk assessment must carefully consider the effect of must carefully consider the effect of comorbid illness in this population. comorbid illness in this population. Although age has been reported as Although age has been reported as an independent risk factor for an independent risk factor for postoperative mortality, this postoperative mortality, this observation may represent the observation may represent the unmeasured aspects of comorbid unmeasured aspects of comorbid disease and the severity of illness.disease and the severity of illness.

In an older adult patient, the In an older adult patient, the preoperative evaluation seeks to preoperative evaluation seeks to identify and quantify the magnitude identify and quantify the magnitude of comorbid disease and optimize the of comorbid disease and optimize the patient's condition before surgery patient's condition before surgery when possible. Preoperative testing when possible. Preoperative testing is based on findings suggested in the is based on findings suggested in the history and physical examination. history and physical examination.

Generally, elderly patients have an Generally, elderly patients have an ECG, chest radiograph, CBC, and ECG, chest radiograph, CBC, and determination of glucose, creatinine, determination of glucose, creatinine, blood urea nitrogen, and albumin blood urea nitrogen, and albumin levels. Additional preoperative levels. Additional preoperative studies are based on the criteria studies are based on the criteria discussed earlier for evaluation of discussed earlier for evaluation of patient and procedural risk. patient and procedural risk.

Predicting and preventing Predicting and preventing postoperative delirium are important postoperative delirium are important aspects of the perioperative care of aspects of the perioperative care of the elderly. Patients with three or the elderly. Patients with three or more of the following have a 50% more of the following have a 50% risk for postoperative delirium: risk for postoperative delirium:

70 years or older; self-reported 70 years or older; self-reported alcohol abuse; poor cognitive status; alcohol abuse; poor cognitive status; poor functional status; markedly poor functional status; markedly abnormal preoperative serum abnormal preoperative serum sodium, potassium, or glucose level; sodium, potassium, or glucose level; noncardiac thoracic surgery; and noncardiac thoracic surgery; and aortic aneurysm surgery. aortic aneurysm surgery.

This risk is explained to the patient This risk is explained to the patient and the family along with the and the family along with the symptoms of postoperative delirium. symptoms of postoperative delirium. If delirium does occur, metabolic and If delirium does occur, metabolic and infectious causes need to be infectious causes need to be investigated before labeling the investigated before labeling the event as sundowning. event as sundowning.

Nutritional StatusNutritional Status Evaluation of the patient's nutritional Evaluation of the patient's nutritional

status is part of the preoperative status is part of the preoperative evaluation. A history of weight loss evaluation. A history of weight loss greater than 10% of body weight greater than 10% of body weight over a 6-month period or 5% over a over a 6-month period or 5% over a month is significant. month is significant.

Albumin or prealbumin levels and Albumin or prealbumin levels and immune competence (as assessed by immune competence (as assessed by delayed hypersensitivity reaction) delayed hypersensitivity reaction) may help identify patients with some may help identify patients with some degree of malnutrition, and physical degree of malnutrition, and physical findings of temporal wasting, findings of temporal wasting, cachexia, poor dentition, ascites, or cachexia, poor dentition, ascites, or peripheral edema may be peripheral edema may be corroborative. The degree of corroborative. The degree of malnutrition is estimated on the basis malnutrition is estimated on the basis of weight loss, physical findings, and of weight loss, physical findings, and plasma protein assessment plasma protein assessment

The adequacy of a nutritional The adequacy of a nutritional regimen can be confirmed with a regimen can be confirmed with a number of serum markers. Albumin number of serum markers. Albumin (half-life, 14-18 days), transferrin (half-life, 14-18 days), transferrin (half-life, 7 days), and prealbumin (half-life, 7 days), and prealbumin (half-life, 3-5 days) levels can be (half-life, 3-5 days) levels can be determined on a regular basis in determined on a regular basis in hospitalized patients. hospitalized patients.

These proteins are responsive to These proteins are responsive to stress conditions, however, and their stress conditions, however, and their synthesis may be inhibited in the synthesis may be inhibited in the immediate perioperative period. immediate perioperative period. Once a patient is on a stable regimen Once a patient is on a stable regimen and in the anabolic phase of and in the anabolic phase of recovery, these markers reflect the recovery, these markers reflect the adequacy of nutritional efforts. adequacy of nutritional efforts.

The effect of perioperative nutritional The effect of perioperative nutritional support on outcomes has been support on outcomes has been studied in a number of trials. studied in a number of trials.

Patients with severe malnutrition (as Patients with severe malnutrition (as defined by a combination of weight defined by a combination of weight loss, visceral protein indicators, and loss, visceral protein indicators, and prognostic indices) appear to benefit prognostic indices) appear to benefit most from preoperative parenteral most from preoperative parenteral nutrition, as demonstrated in study nutrition, as demonstrated in study groups treated with total parenteral groups treated with total parenteral nutrition for 7 to 10 days before nutrition for 7 to 10 days before surgery for gastrointestinal malignancy surgery for gastrointestinal malignancy

The majority of studies show a The majority of studies show a reduction in the rate of postoperative reduction in the rate of postoperative complications from approximately complications from approximately 40% to 30%. The use of total 40% to 30%. The use of total parenteral nutrition postoperatively parenteral nutrition postoperatively in similar groups of patients is in similar groups of patients is associated with an approximately associated with an approximately 10% increase in complication rates 10% increase in complication rates

Well-nourished patients undergoing Well-nourished patients undergoing surgery do not appear to benefit surgery do not appear to benefit from aggressive perioperative from aggressive perioperative nutritional support; parenteral nutritional support; parenteral nutrition is additionally associated nutrition is additionally associated with increased septic complications. with increased septic complications.

Generally, nutritional support begins Generally, nutritional support begins within 5 to 10 days after surgery in within 5 to 10 days after surgery in all patients unable to resume their all patients unable to resume their normal diet. Such support may take normal diet. Such support may take the form of nasoenteric feeding, the form of nasoenteric feeding, parenteral nutrition, or a combination parenteral nutrition, or a combination of the two of the two

ObesityObesity The perioperative mortality rate is The perioperative mortality rate is

significantly increased in patients significantly increased in patients with clinically severe obesity (body with clinically severe obesity (body mass index [BMI] >40 kg/m2 or BMI mass index [BMI] >40 kg/m2 or BMI >35 kg/m2 with significant comorbid >35 kg/m2 with significant comorbid conditions). The goal of preoperative conditions). The goal of preoperative evaluation of an obese patient is to evaluation of an obese patient is to identify risk factors that might modify identify risk factors that might modify perioperative care of the patient. perioperative care of the patient.

Clinically severe obesity is associated Clinically severe obesity is associated with a higher frequency of essential with a higher frequency of essential hypertension, pulmonary hypertension, pulmonary hypertension, left ventricular hypertension, left ventricular hypertrophy, congestive heart hypertrophy, congestive heart failure, and ischemic heart disease failure, and ischemic heart disease

Patients with no or one of these risk Patients with no or one of these risk factors receive a β-blocker factors receive a β-blocker preoperatively for cardioprotection. preoperatively for cardioprotection. Patients with two or more risk factors Patients with two or more risk factors undergo noninvasive cardiac testing undergo noninvasive cardiac testing preoperatively preoperatively

Obesity is also a risk factor for Obesity is also a risk factor for postoperative wound infection. The rate postoperative wound infection. The rate of wound infections is much lower with of wound infections is much lower with laparoscopic surgery in this group, laparoscopic surgery in this group, which could have a bearing on selection which could have a bearing on selection of the operative approach. Obesity is an of the operative approach. Obesity is an independent risk factor for DVT and PE; independent risk factor for DVT and PE; therefore, appropriate prophylaxis is therefore, appropriate prophylaxis is instituted in these patients.instituted in these patients.

PREOPERATIVE CHECKLIST PREOPERATIVE CHECKLIST preoperative evaluation concludes preoperative evaluation concludes

with a review of all pertinent studies with a review of all pertinent studies and information obtained from and information obtained from investigative tests. Documentation of investigative tests. Documentation of this review is made in the chart, this review is made in the chart, which represents an opportunity to which represents an opportunity to ensure that all necessary and ensure that all necessary and pertinent data have been obtained pertinent data have been obtained and appropriately interpreted and appropriately interpreted

Informed consent after discussion Informed consent after discussion with the patient and family members with the patient and family members regarding the indication for the regarding the indication for the anticipated surgical procedure, as well anticipated surgical procedure, as well as its risks and proposed benefits, are as its risks and proposed benefits, are documented in the chart. The documented in the chart. The preoperative checklist also gives the preoperative checklist also gives the surgeon an opportunity to review the surgeon an opportunity to review the need for β-blockade, DVT prophylaxis, need for β-blockade, DVT prophylaxis, and prophylactic antibiotics. and prophylactic antibiotics.

Preoperative orders are written and Preoperative orders are written and reviewed. The patient receives reviewed. The patient receives written instructions regarding the written instructions regarding the time of surgery and management of time of surgery and management of special perioperative issues such as special perioperative issues such as fasting, bowel preparation, and fasting, bowel preparation, and medication use.medication use.

Antibiotic ProphylaxisAntibiotic Prophylaxis Appropriate antibiotic prophylaxis in Appropriate antibiotic prophylaxis in

surgery depends on the most likely surgery depends on the most likely pathogens encountered during the pathogens encountered during the surgical procedure. The type of surgical procedure. The type of operative procedure is helpful in operative procedure is helpful in deciding the appropriate antibiotic deciding the appropriate antibiotic spectrum and is considered before spectrum and is considered before ordering or administering any ordering or administering any preoperative medication. preoperative medication.

Prophylactic antibiotics are not Prophylactic antibiotics are not generally required for clean (class I) generally required for clean (class I) cases, except in the setting of cases, except in the setting of indwelling prosthesis placement or indwelling prosthesis placement or when bone is incised. Patients who when bone is incised. Patients who undergo class II procedures benefit undergo class II procedures benefit from a single dose of an appropriate from a single dose of an appropriate antibiotic administered before the antibiotic administered before the skin incision. skin incision.

For abdominal (hepatobiliary, For abdominal (hepatobiliary, pancreatic, gastroduodenal) cases, pancreatic, gastroduodenal) cases, cefazolin is generally used. cefazolin is generally used. Contaminated (class III) cases require Contaminated (class III) cases require mechanical preparation or parenteral mechanical preparation or parenteral antibiotics with both aerobic and antibiotics with both aerobic and anaerobic activity. anaerobic activity.

Such an approach is taken in the Such an approach is taken in the setting of emergency abdominal setting of emergency abdominal surgery, as for suspected appendicitis, surgery, as for suspected appendicitis, and in trauma cases. Dirty or infected and in trauma cases. Dirty or infected cases often require the same cases often require the same antibiotic spectrum, which can be antibiotic spectrum, which can be continued into the postoperative continued into the postoperative period in the setting of ongoing period in the setting of ongoing infection or delayed treatment. infection or delayed treatment.

The appropriate antibiotic is chosen The appropriate antibiotic is chosen before surgery and administered before surgery and administered before the skin incision is made before the skin incision is made Repeat dosing occurs at an Repeat dosing occurs at an appropriate interval, usually 3 hours appropriate interval, usually 3 hours for abdominal cases or twice the half-for abdominal cases or twice the half-life of the antibiotic, although the life of the antibiotic, although the patient's renal function may alter the patient's renal function may alter the timing timing

Perioperative antibiotic prophylaxis Perioperative antibiotic prophylaxis generally is not continued beyond generally is not continued beyond the day of surgery. With the advent the day of surgery. With the advent of minimal-access surgery, the use of of minimal-access surgery, the use of antibiotics seems less justified antibiotics seems less justified because the risk for wound infection because the risk for wound infection is extremely low. is extremely low.

For example, routine antibiotic For example, routine antibiotic prophylaxis in patients undergoing prophylaxis in patients undergoing laparoscopic cholecystectomy for laparoscopic cholecystectomy for symptomatic cholelithiasis is of symptomatic cholelithiasis is of questionable value. It may have a questionable value. It may have a role, however, in cases that result in role, however, in cases that result in prosthetic graft (i.e., mesh) prosthetic graft (i.e., mesh) placement, such as laparoscopic placement, such as laparoscopic hernia repair. hernia repair.

Preoperative Mechanical Preoperative Mechanical Bowel Cleansing Bowel Cleansing

Mechanical bowel preparation with Mechanical bowel preparation with the addition of oral antibiotics was the addition of oral antibiotics was the standard of care for several the standard of care for several decades for any intestinal surgery. decades for any intestinal surgery. More recent studies have evaluated More recent studies have evaluated the need for both oral antibiotics and the need for both oral antibiotics and mechanical cleansing mechanical cleansing

Oral antibiotics confer no benefit to Oral antibiotics confer no benefit to the patient and may increase the risk the patient and may increase the risk for postoperative infection with for postoperative infection with Clostridium difficile. In addition, Clostridium difficile. In addition, although it seems intuitive that although it seems intuitive that removal of bulk fecal material would removal of bulk fecal material would decrease the risk for anastomotic decrease the risk for anastomotic and infectious complications, the and infectious complications, the opposite is true. opposite is true.

A recent meta-analysis showed that A recent meta-analysis showed that both of these events are not both of these events are not decreased and may be increased decreased and may be increased with mechanical cleansing.with mechanical cleansing.

Review of MedicationsReview of Medications Careful review of the patient's home Careful review of the patient's home

medications is a part of the medications is a part of the preoperative evaluation before any preoperative evaluation before any operation; the goal is to operation; the goal is to appropriately use medications that appropriately use medications that control the patient's medical control the patient's medical illnesses while minimizing the risk illnesses while minimizing the risk associated with anesthetic-drug associated with anesthetic-drug interactions or the hematologic or interactions or the hematologic or metabolic effects of some commonly metabolic effects of some commonly used medications and therapiesused medications and therapies

The patient is asked to name all The patient is asked to name all medications, including psychiatric medications, including psychiatric drugs, hormones, and drugs, hormones, and alternative/herbal medications, and alternative/herbal medications, and to provide dosages and frequency.to provide dosages and frequency.

In general, patients taking cardiac In general, patients taking cardiac drugs, including β-blockers and drugs, including β-blockers and antiarrhythmics, pulmonary drugs antiarrhythmics, pulmonary drugs such as inhaled or nebulized such as inhaled or nebulized medications, or anticonvulsants, medications, or anticonvulsants, antihypertensives, or psychiatric antihypertensives, or psychiatric drugs are advised to take their drugs are advised to take their medications with a sip of water on medications with a sip of water on the morning of surgery. the morning of surgery.

Parenteral forms or substitutes are Parenteral forms or substitutes are available for many drugs and may be available for many drugs and may be used if the patient remains NPO for used if the patient remains NPO for any significant period any significant period postoperatively. It is important to postoperatively. It is important to return patients to their normal return patients to their normal medication regimen as soon as medication regimen as soon as possible possible

Two notable examples are the Two notable examples are the additional cardiovascular morbidity additional cardiovascular morbidity associated with the perioperative associated with the perioperative discontinuation of β-blockers and discontinuation of β-blockers and rebound hypertension with abrupt rebound hypertension with abrupt cessation of the antihypertensive cessation of the antihypertensive clonidine. Medications such as lipid-clonidine. Medications such as lipid-lowering agents or vitamins can be lowering agents or vitamins can be omitted on the day of surgery. omitted on the day of surgery.

Some drugs are associated with an Some drugs are associated with an increased risk for perioperative increased risk for perioperative bleeding and are withheld before bleeding and are withheld before surgery. Drugs that affect platelet surgery. Drugs that affect platelet function are withheld for variable function are withheld for variable periods: aspirin and clopidogrel periods: aspirin and clopidogrel (Plavix) are withheld for 7 to 10 days, (Plavix) are withheld for 7 to 10 days, whereas NSAIDs are withheld whereas NSAIDs are withheld between 1 day (ibuprofen and between 1 day (ibuprofen and indomethacin) and 3 days (naproxen indomethacin) and 3 days (naproxen and sulindac), depending on the and sulindac), depending on the drug's half-life drug's half-life

Because the use of estrogen and Because the use of estrogen and tamoxifen has been associated with tamoxifen has been associated with an increased risk for an increased risk for thromboembolism, they probably thromboembolism, they probably need to be withheld for a period of 4 need to be withheld for a period of 4 weeks preoperatively weeks preoperatively

The widespread use of herbal The widespread use of herbal medications has prompted review of medications has prompted review of the effects of some commonly used the effects of some commonly used preparations and their potential preparations and their potential adverse outcomes in the adverse outcomes in the perioperative period. These perioperative period. These substances may fail to be recorded in substances may fail to be recorded in the preoperative evaluation, the preoperative evaluation, although important metabolic and although important metabolic and hematologic effects can result from hematologic effects can result from their regular use their regular use

Generally, the use of herbal Generally, the use of herbal medications is stopped medications is stopped preoperatively, but this needs to be preoperatively, but this needs to be done with caution in patients who done with caution in patients who report the use of valerian, which may report the use of valerian, which may be associated with a benzodiazepine-be associated with a benzodiazepine-like withdrawal syndrome. like withdrawal syndrome.

Preoperative FastingPreoperative Fasting The standard order of “NPO past The standard order of “NPO past

midnight” for preoperative patients is midnight” for preoperative patients is based on the theory of reduction of based on the theory of reduction of volume and acidity of the stomach volume and acidity of the stomach contents during surgery. Recently, contents during surgery. Recently, guidelines have recommended a shift guidelines have recommended a shift to allow a period of restricted fluid to allow a period of restricted fluid intake up to a few hours before intake up to a few hours before surgery surgery

The ASA recommends that adults The ASA recommends that adults stop intake of solids for at least 6 stop intake of solids for at least 6 hours and clear fluids for 2 hours. hours and clear fluids for 2 hours. When the literature was recently When the literature was recently reviewed by the Cochrane group, reviewed by the Cochrane group, they found 22 trials in healthy adults they found 22 trials in healthy adults that provided 38 controlled that provided 38 controlled comparisons. comparisons.

Very few trials investigated the Very few trials investigated the fasting routine in patients at higher fasting routine in patients at higher risk for regurgitation/aspiration risk for regurgitation/aspiration (pregnant, elderly, obese, or those (pregnant, elderly, obese, or those with stomach disorders). There is also with stomach disorders). There is also increasing evidence that preoperative increasing evidence that preoperative carbohydrate supplementation is safe carbohydrate supplementation is safe and may improve a patient's and may improve a patient's response to perioperative stressresponse to perioperative stress

There was no evidence that the There was no evidence that the volume or pH of gastric contents volume or pH of gastric contents differed with the length and type of differed with the length and type of fasting. Though not reported in all fasting. Though not reported in all the trials, there did not appear to be the trials, there did not appear to be an increased risk for an increased risk for aspiration/regurgitation with a aspiration/regurgitation with a shortened period of fasting. shortened period of fasting.

Surgeons and anesthesiologists Surgeons and anesthesiologists should evaluate the evidence and should evaluate the evidence and consider adjusting their standard consider adjusting their standard fasting policies.fasting policies.