DR.CHARULATHA.RPreanaesthetic evaluation

anaesthesiologist = perioperative physician

Use our unique knowledge and experience to manage medical complexities related to surgery

3 % of perioperative adverse events were related to inadequate preoperative assessment

goals

1.patients can safely tolerate anaesthesia for planned surgical procedure

2.to mitigate risks associated with overall perioperative period

How do we achieve it?

Document comorbid illness Perform focussed clinical

examination Optimize preexisting medical

conditions Make selective referrals to specialists Order preoperative investigations Initiate interventions to reduce

perioperative risk Discuss aspects of perioperative care

Anaesthesiologist lead PAC More selective ordering of laboratory

tests Reduced healthcare costs Reduced patient anxiety Improved acceptance of regional

anaesthesia Fewer case cancellations on day of

surgery Shorter duration of hospitalization Lower hospital costs

Medical consultation?

Management of unstable medical conditions before elective surgery

Preop optimization of poorly controlled medical diseases

Clinically relevant preop diagnostic workup

Uncommon medical disorder

Detecting disease

All that is required is clinical examination

History taking -56% Physical examination -73% ECGs and chest Xrays -3% Stress tests -6 % Respiratory ,urinary,neurolgic-history

Components of medical history Ask the right question Indication for surgery and planned

procedure Development of surgical condition

and prior related therapies Current and past medical

problems,pervious surgical procedures,types of anaesthesia ,any anaesthesia related complications

allergies

Personal history

Tobacco, alcohol ,illicit drug use Quantitative documentation of tobacco

exposure Pseudocholinesterase deficiency/

Malignant hyperthermia Snoring and excessive daytime sleepiness Last menstrual period GE reflux Excessive bleeding problems

Comorbid conditions

Severity,stability,exarcerbations Prior treatments,planned

interventions Degree of control Activity limiting nature of problems Medications and schedules Recent corticosteroid use

METs

Assessment of functional capacity Metabolic equivalents of the task Measure of volume consumed during

an activity Poor exercise capacity may be the

cause or result of cardiopulmonary disease

Inability to perform average levels of exercise increases risk of perioperative complications

Physical examination

Vital signs BMI Airway examiation Evaluation of heart,lungs ,spine Direct observation of exercise

tolerance Basic neurologic examination Carotid bruit

Components of airway examination Length of upper incisors Visibility of uvula Compliance of mandibular space Thyromental distance Length and circumference of neck Range of motion of head and neck Relationship of upper incisors to

lower incisors

Cardiovascular diseaase

Hypertension Ischemic heart disease Coronary stents Heart failure Murmurs and valvular abnormalities Rhythm disturbances in preoperative

ECG Peripheral arterial disease

hypertension

Identify cause,other cardiovascular risk factors,end organ damage

BP measurement in both arms Investigations? Elective surgery delayed when systolic>

200 mm Hg or diastolic >115 mm Hg BP less than 180/110 mm Hg Future appropriate postop management of

inadequately treated hypertension ACE inhibitors and ARBs

Ischemic heart disease Step 1-emergency surgery Step2- active cardiac conditions Step 3 –low risk surgery Step 4- functional capacity Step 5- clinical predictors

Revised cardiac risk index High risk surgery Ischemic heart disease History of congestive heart failure History of cerebrovascular disease Diabetes mellitus requiring insulin Creatinine >2.0 mg/dL

Preoperative anaemia is associated with increased perioperative cardiac events

Increasing blood transfusion rates does not decrease perioperative cardiac risk

Anaemia decreases effects of beta blocker therapy

Increased harm when the patient is bleeding

ECG

Patients with symptoms /suggestive of ischemia

For intermediate to high risk surgical procedures

Not needed in superficial procedures or simply because of advanced age

Q waves,RBBB,LBBB - important

Statins and beta blockers continued Beta blockers should be started

several days before the procedure Caution in patients with

cerebrovascular disease Aspirin is continued where the risk of

cardiac events exceeds risk of major bleeding

Neurologic disease

Cerebrovascular disease- recent stroke or TIA is a very strong predictor of subsequent perioperative stroke

Asymtomatic bruit- carotid doppler studies

Seizure disorder- CBC and electrolytes

Parkinson disease Neuromuscular junction disorders

Preoperative tests

Should be based on 1.patient ‘s medical history 2.proposed surgical procedure 3.potential for intraoperative blood

loss

Selective testing enhances the standing of speciality in perioperative medicine

CBC

History of increased bleeding Hematologic disorders Renal disease Recent chemo or radiation Corticosteroid or anticoagulant

therapy Poor nutritional status Trauma Anticipated high blood loss

Renal function testing

Diabetes and hypertension Cardiac disease Fluid overload Renal transplantation Recent chemotherapy Potential dehydration Hematuria,oliguria,anuria

Liver function tests

History of hepatitis Jaundice Cirrhosis Hepatotoxic drug exposure Bleeding disorders Tumor involvement of liver

Coagulation testing

Known bleeding disorders Previous excessive intraoperative

bleeding Hepatic disease Poor nutritional status Anticoagulants

Routine testing not needed unless coagulapathy is suspected or known

Chest radiograph

No evidence indicates that routine preoperative chest radiographs provide prognostically important information for assessing patients perioperative risk

Rales or rhonchi Advanced copd/suspected pulmonary

edema Pulmonary/mediastinal masses Aortic aneursym

Preoperative risk assessment Improves patient’s understanding Helps clinical decision making Improves perioperative outcomes

ASA PS classification John Hopkins Surgery Risk

Classification System

ASA PS

1- a normal healthy patient 2- a patient with mild systemic

disease 3- a patient with severe systemic

disease 4- a patient with severe systemic

disease that is a constant threat to life

5- a moribund patient who is not expected to survive without operation

6-declared brain dead donor

Role of specialized testingResting echocardiography-ValvesPulmonary hypertensionFixed wall motion abnormalitiesVentricular functionDyspnea of unknown originRecent altered clinical status in a

known heart failure patient

CPET

Non invasive global assessment of exercise capacity

Involves a patient exercising on a treadmill or bicycle for 8 to 12 minutes

Continuous measurement of respiratory gas exchange

Poor exercise capacity associated with increased postoperative mortality/morbidity

PFT

Help differentiate between pulmonary and cardiac cause of dyspnea

Assess perioperative risk in lung resection surgery

Prognostic value limited

Medication management -stop Clopidogrel-7 days before surgery Ticlopidine -14 days Insulin- short acting –discontinue Type 1 diabetes- 1/3 rd of long acting

morning dose Type 2- upto ½ of long acting or

combination OHAs Diuretics –except thiazides

stop

Warfarin- 4 days before surgery except for patients having cataract surgery withot bulbar block

NSAIDS – 48 hrs before surgery Sildenafil-24 hrs before surgery ACEI and ARBs

continue

Antihypertensive medications Cardiac drugs Antidepressants,anxiolytics Thyroid Anticonvulsant Asthma Steroids Statins MAO inhibitors

Preoperative fasting status Clear fluids -2 hrs Breast milk -4 hrs Formula milk -6 hrs Light meal -6 hrs Fried fatty meal -8 hrs

Postoperative pain management Visual analog score McGill pain questionnaire Uses 1.patient’s concern 2.preoperative instructions 3.improves patient acceptance of

regional anaesthesia 4.patients with chronic pain

syndromes