anesthetic mngt -high risk obg pts

8/8/2019 Anesthetic Mngt -High Risk OBG Pts

http://slidepdf.com/reader/full/anesthetic-mngt-high-risk-obg-pts 1/23

9/29

Anesthetic Management Of

High Risk Obstetric Patients

Can We Improve The outcome?

Salah Mostafa Asida M.D.

ou a ey n vers y

Qena University Hospital



9/29



9/29

obstetrics

To understand anesthetic risk in obstetric patients it is important first tofully appreciate obstetric risk in general . Al though the majority of womeno c ear ng age are ea y an cou e cons ere o e a goosurgical risk yet, pregnancy itself , certain maternal/ fetal factors , and

preexisting medical conditions significantly increase surgical and obstetricrisk.



9/29

obstetrics

Pregnancy related mortality is usually calculated as the number of

pregnancy-related deaths divided by the number of live births . Although

this number has decreased nearly 100-fold since 1900, it has not changed

considerably since 1982. Overall mortality was higher for women >35

years old .

Obstetrics

The leading cause of death was pulmonary embolism (21%) , pregnancy-

induced hypertension (19%), other medical conditions ( 17%) . Major

causes of death associated with stillbirth were hemorrhage (21%) ,

pregnancy-induced hypertension (20%) , and sepsis (19%) . Only 34% of

women died within 24 hrs of delivery whereas 55% died between 1 and 42

days and another 11% died between 43 one year .



9/29

obstetrics

Normal straightforward labor cannot be conducted without theattendance of anesthesiologist. Since the course of labor can be

. be divided on either

the mother or the fetus

or both. So, we have maternal risk factors and

fetal risk factors

minor risk factors can be thrown on the experience of the obstetricianand anesthesiologist and on the co-operation between them, and on theava a ty o ac t es or ac ng cu t s tuat ons spec a y a rwaymanagement or bleeding disorders.

obstetrics

So we should ask ourselves is there really low risk and high risk?

The answer is

Not all cases that can be considered low risk can go straightforward

without serious problems

But high risk patients usually receive more intensive attention from the

start as they are usually diagnosed before delivery.



9/29

obstetrics

What is maternal risk?

re nant women with cardiac disease such as:

valve lesions

Ischemic heart disease

Myocardial infarction

Peripartum cardiomyopathy

Congenital heart disease

obstetrics

Mitral stenosis is the most common chronic rheumatic valvular lesion

in pregnancy.

Pregnant women with mitral stenosis present clinically with symptoms

related to left sided heart failure such as dyspnea on exertion or

orthopnea or symptoms related to right sided heart failure in long

standing cases such as leg edema and ascites.

Medical follow up by cardiologist markedly help to improve the

general condition of these women and hence outcome



9/29

obstetrics

They usually study these cases by echocardiography for evaluation of

hemodynamics across the valve and the impact of stenosis on the

pulmonary circulation

Balloon valvuloplasty presents a good solution for the problem in

selected cases. Although surgical intervention during pregnancy carries

its own risk for the mother and the fetus

During the course of pregnancy anemia should be corrected promptly to

improve oxygen carrying capacity of the blood and avoid unnecessary

.

obstetrics

The anesthetic approach to these patients should include reception of these

case for evaluation as soon as the patient is admitted to the hospital not just

dealing with the patient in the theater in the late stage of delivery as usually

occurs.( anesthesia resident in obstetric clinic ?)

Intravenous and intra-arterial lines should be inserted

Oxygen therapy

Fluid restriction

Antibiotics



9/29

obstetrics

Whether vaginal or ceserean delivery is planned lumber epidural

catheter should be inserted for continuous epidural analgesia

When CS is decided combined spinal epidural can be done with

intrathecal narcotics to maintain rapid onset of the block with minimal

hemodynamic changes

Regional OR General for CS?

Suggested doses of local anesthetic &fentanyl for continuous lumber epidural

analgesia

Drug initial dose infusion rate

Ropivacaine 10 ml 0.1% 6-12ml/hr

Bupivacaine 10 ml 0.25% 6-12ml/hr

Fentanyl 500-100 ug 1-4 ug/ml

obstetrics

so long there is no contra indication for regional it is the first choice

In some cases of difficulties in the back of the atient such as k hosis

or obesity or sometimes infections of the skin or un- cooperative patient

we can resort to GA with good preoxygenation rapid sequence

induction and tools for facing the possibility of difficult airway.

Hemodynamic stability should be our aim as tachycardia causes

pulmonary congestion and inadequate space for ventilation and gas

exchange hence unnecessary hypoxemia

compromise renal function and coronary circulation



9/29

obstetrics

Postoperative analgesia is maintained through the epidural catheter by

injecting narcotics

Patients with ischemic heart disease follow the same lines

Optimizing cardiac work and oxygen supply through the coronary

circulation is our target

We recommend control of heart rate by beta blockers and blood pressure

help to avoid the risk of worsening the ischemic state or developing

infarction

Coronar stentin is now done safel and hel im rove the coronar

perfusion

obstetrics

If it could be done early in the first trimester of pregnancy it helps much

improving the coronary perfusion.

Anemia and chest infection should be corrected promptly before delivery

Regional anesthesia is preferred from GA as it provides more

hemodynamic stability ,intense and extended analgesia, and safety as

regards the baby.



9/29

obstetrics

Patients with respiratory diseases such as asthma which occurs in 1% of

pregnant females sometimes presents great challenge to anesthesiologists

because they may get worse with pregnancy or stay stable

These patients are usually on long term steroid therapy and

sympathmimetics are no longer effective against hypotension

They are very susceptible to chest infection : prophylactic antibiotics is

recommended.

Their airway is easily irritated with the production of copious secretions

obstetrics

Co-operative patients deals well with regional techniques of anesthesia

Preloading with one liter of lactated ringer help avoid hypotension and

obveates the need for sympathmimetics which may be ineffective in these

situations (tolerance or tachyphilaxis)

Care should be taken to avoid respiratory depressant narcotics such as

sofentanil as it may be dangerous in these cases

Continuious oxygen administration by nasal canula and light sedation to

allay the anxiety of labor is recommended as it decreases the incidence of

asthmatic attacks.



9/29

obstetrics

For un co-operative patients or those refusing regional anesthesia GA is

required

Preoxegenation is mandatory

Ketamine for induction

Succinylcholine or rocuronium for intubation

Halothane or isoflurane for maintenance and help bronchodilatation

Avoid sofentanil as it has powerfull respiratory depressant effect

Naloxone should be at hand

obstetrics

Diabetes: patients presented for delivery with glucose intolerance may be

classified into those who were diabetic before pregnancy or those who

develop glucose intolerance during pregnancy

In both cases monitoring of blood glucose level and tight glycaemic control

is required specially if GA is planned .

Short acting insulin is preferred for control of blood sugar.



9/29

obstetrics

Obesity

Obesity is an enemy to both surgeons and anesthesiologists morbidly obese

mothers with BMI more than 40 are characterized by a number of

difficulties

Diabetes

Hypertension

Tendency for thromboembolism

Higher rate of instrumental delivery

obstetrics

Respiratory functions are usually impaired in these patients with reduction

of FRC and total lung capacity with bad tolerance of hypoxemia

Short neck , large breast , big tongue , edema of airway makes intubation a

nightmare : consider LMA monitor etCO2

Regional analgesia and anesthesia may be difficult

Patients laying in the lateral position may be easier to find a space to

introduce spinal or epidural needle than sitting position

Long needles are now available



9/29

obstetrics

What about obstetrically risky patients

They may be one of the previously mentioned cases with superadded

obstetric problem or patients with good general condition but with some

problem as regards pregnancy and placental position

Another category involves patients with fetal distress or precious baby

obstetrics

The triad of bleeding , coagulopathy and difficult airway represents a great

challenge to the medical team dealing with those women with a problem in

pregnancy and delivery such as :

Placenta previa

Abruptio placenta

Rupture uterus

Retained placenta

Placenta accreta

er ne nvers on



9/29

obstetrics

Postpartum bleeding can be included in 4Ts tone→atony

tissue→retained placenta

trauma→cervical lacerations

thrombin→coagulopathy

And the word 4Ts reffers to the age around 40

Peripartum loss of more than 500 cc of blood with reduction of blood

pressure more than 10% of baseline is a warning sign of complications

obstetrics

Maternal physiology is prepared for this situation

Blood volume is increased 20%

Coagulation factors are activated ( DIC)

The uterus by contraction exerts a tourniquet effect on its own blood

vessels and prevents bleeding by constricting these vessels.

From the obstetric point of view the position of the placenta and the fetus

are crucial in determining the course of labor

So plancental position and separation adds to the risk factors associated

position



9/29

obstetrics

The incidence of abnormal and risky situations is as follows

Uterine atony 1:8

Abruptio placenta 1:30

Retained placenta 1: 100

Placenta previa 1:200

Placenta accreta 1: 2000

Rupture uterus 1:2300

Uterine inversion 1: 6400 (Crochetiere C : obstetric emergencies. Anesthesiology

Clincs of North America vol 21, 1. marsh 2003)

obstetrics

These critical situations should be diagnosed early in the course of labor

The anesthesiologist attendance and cooperation is as important as the obstetrician

Full hematological study should be done to the patient and possible blood donors as

soon as the patient is admitted to the hospital.

Large bore intravenous lines should be inserted before the patient get shocked and

veins are collapsed at least 3 lines.

Do not fall behind the patient :do not wait until the patient’s blood pressure falls

and then start blood replacement and transfusion.

Start infusion of warm crystalloids as early as possible

ons er co o n us on un oo s rea y

Whole blood is better as it provides clotting factors specially if fresh



9/29

obstetrics

Start central venous line for monitoring and infusion

Monitor urine output through urethral catheter.

Warming and oxygenation improves the patient’s general condition and

moral.

Anesthesia depends on :the patient’s general condition

co-operation of the patient

co-operation of the obstetrician

experience of anesthetist

available facilities

obstetrics

Epidural catheter can be inserted in early diagnosed cases for both pain

relief and for anesthesia for CS if decided

Preloading with at least one liter ringer’s solution decreases the incidence

of hypotension after the block

Spinal anesthesia may be followed by sudden hypotension and better

avoided

It is not recommended if coagulopathy is anticipated

Narcotic- based GA with induction with ketamine followed by succinyl

choline :ra id se uence induction and maintenance with volatile a ent.



9/29

obstetrics

Postpartum analgesia can be done by epidural narcotics

ICU admission for monitoring hemodynamics , respiratory and renal

functions helps improving the outcome.

The second threat in high risk obstetric patients is coagulopathy or

DIC

Disseminated intravascular coagulopathy also known as consumptive

coagulopathy, is a pathological activation of coagulation mechanisms. As

its name suggests, it leads to the formation of small blood clots inside the

blood vessels throu hout the bod . As the small clots consume all the

available coagulation proteins and platelets, normal coagulation is

disrupted and abnormal bleeding occurs from the skin,the digestive tract,

the respiratory tract and surgical wounds.

obstetrics

Half of the cases seen is associated with pregnancy in abruptio placentae,

retained dead fetus, pre-eclampsia, amniotic fluid embolism

Cancers of lung, pancreas, prostate and stomach

Massive tissue injury: Trauma, burns, extensive surgery

Infections: Gram-negative sepsis, Neisseria meningitidis, Streptococcus

pneumoniae, malaria, histoplasmosis, aspergillosis, Rocky mountain

spotted fever

Miscellaneous cases in: Liver disease, snake bite, acute intravascular

hemol sis iant heman ioma shock heat stroke vasculitis aortic aneurysm, Serotonin syndrome.



9/29

obstetrics

Definitive diagnosis depends on the result of:

Thrombocytopenia

Prolongation of prothrombin time and activated partial thromboplastin time

A low fibrinogen concentration

Increased levels of fibrin degradation products in the blood.

The onset may be fulminant as in amniotic fluid embolism or insiduious as

in retained dead fetus or carcinomatosis

Coagulation factors:

I Fibrinogen VIII Antihemophilic factor

II Prothrombin IX Christmas factor

III Tissue thromboplastin X Stuart factor

IV Calcium XI Plasma thromboplastin antecedentV Proaccelerin XII Hageman factor

VII Proconvertin XIII Fibrin stabilsing factor

obstetrics

The management of acute and chronic forms of disseminated intravascular

coagulation (DIC) should primarily be directed at treatment of the underlying

sor er. yp ca y, resu s n s gn can re uc ons n p a e e coun an

increases in coagulation times (PT and aPTT).

Most clinicians will provide platelet replacement if platelet counts drop

below 20 X 106/mL. Previously, concern has been raised regarding "fueling

the fire" of consumption by providing replacement therapy; however, this has

never been established in research studies.

Cryoprecipitates should not routinely be used as replacement therapy in DIC

as they lack several specific factors (factor V). Additionally, worsening of the

coagulopathy via the presence of small amounts of activated factors is a

theoretical risk. Otherwise



9/29

obstetrics

the AT (antithrombin) pathway is an important inhibitor of coagulation in

normal patients. This system is largely depleted and incapacitated in acute

DIC. As a result, several studies have evaluated the utility of AT

replacement in DIC. Most have demonstrated benefit in terms of improving

laboratory values and even organ function. However, large-scale

randomized trials have failed to demonstrate any mortality benefit in

patients treated with AT concentrate.

-Levi M, de Jonge E, van der Poll T, ten Cate H. Disseminated intravascular coagulation. Thromb

Haemost. Aug 1999;82(2):695-705. [Medline].

Baudo F, Caimi TM, de Cataldo F, Ravizza A, Arlati S, Casella G, et al.Antithrombin III (ATIII)

replacement therapy in patients with sepsis and/or postsurgical complications: a controlled double-

blind, randomized, multicenter study.Intensive Care Med. Apr 1998;24(4):336-42. [Medline].

Fourrier F, Jourdain M, Tournoys A. Clinical trial results with antithrombin III in sepsis. Crit CareMed. Sep 2000;28(9 Suppl):S38-43. [Medline].

obstetrics

The tissue factor pathway inhibitor (TFPI) mechanism of coagulation

inhibition has likewise received attention as a potential therapy in sepsis-

associated DIC. Indeed, initial results from animal studies have been very

promising in demonstrating the ability of TFPI to arrest DIC and to prevent

the mortality and end-organ damage witnessed in untreated animals.

However, a large, phase III human trial of TFPI in DIC did not show any

mortality benefit.

-Abraham E. Tissue factor inhibition and clinical trial results of tissue factor pathway inhibitor in sepsis. Crit Care Med. Sep

2000;28(9 Suppl):S31-3. [Medline].

-Abraham E, Reinhart K, Opal S, Demeyer I, Doig C, Rodriguez AL, et al.Efficacy and safety of tifacogin (recombinant

tissue factor pathway inhibitor)in severe sepsis: a randomized controlled trial. JAMA. Jul 9 2003;290(2):238-47. [Medline].



9/29

obstetrics

Activated protein C (APC) is an important regulator of coagulation. In

studies of patients with sepsis who had associated organ failure, APC has been shown to reduce mortality and improve organ function. The

PROWESS study (Human Recombinant Activated Protein C Worldwide

Evaluation in Sepsis) documented reductions in 28-day mortality and

improved organ function in APC-treated patients, despite an increase in the

overall number of bleeding complications.40,41 These results were

confirmed by the ENHANCE trial, which also suggested that APC might

be more effective when administered earlier.

-Dhainaut JF, Laterre PF, Janes JM, Bernard GR, Artigas A, Bakker J, et al.Drotrecogin alfa (activated) in thetreatment of severe sepsis patients with multiple-organ dysfunction: data from the PROWESS trial. Intensive Care

Med. Jun 2003;29(6):894-903. [Medline].

-Vincent JL, Angus DC, Artigas A, Kalil A, Basson BR, Jamal HH, et al. Effects of drotrecogin alfa (activated) onorgan dysfunction in the PROWESS trial. Crit Care Med. Mar 2003;31(3):834-40. [Medline].

-Vincent JL, Bernard GR, Beale R, Doig C, Putensen C, Dhainaut JF, et al.

Drotrecogin alfa (activated) treatment in severe sepsis f rom the global open-label trial ENHANCE: further evidencefor survival and safety and implications for early treatment. Crit Care Med. Oct 2005;33(10):2266-77. [Medline].

obstetrics

Recombinant factor VIIa has also been demonstrated to be useful in cases

of severe bleeding as can be seen in DIC. However, giving the

procoagulant effect of rVIIa, a careful consideration of the risks and

benefits in patients with DIC should be undertaken before administration.

Further, antifibrinolytic agents, such as epsilon-aminocaproic acid or

tranexamic acid, can also be considered in patients with DIC in which

bleeding predominates. These agents should always be administered with

heparin to arrest their prothrombotic effects.

-Franchini M, Lippi G, Manzato F. Recent acquisitions in the pathophysiology,diagnosis and treatment of disseminated

intravascular coagulation. Thromb J. 2006;4:4. [Medline]

.

-Levi M. Current understanding of disseminated intravascular coagulation. Br J Haematol. Mar 2004;124(5):567-76.

[Medline].



9/29

obstetrics

In short:

Treatment for acute disseminated intravascular coagulation (DIC) includes anticoagulants, blood components, and antifibrinolytics.

Anticoagulants :These agents are used in the treatment of clinically evident intravascular thrombosis when the patient continues to bleed or clot 4-6 h after initiation of primary andsupportive therapy.

Thrombosis can present as purpura fulminans or acral ischemia.

Take special precaution in obstetric emergencies (not recommended ).

The anti-inflammatory properties of antithrombin III may be particularly useful in DICsecondary to sepsis.


I Fibrino en VIII Antihemo hilic factor



IV Calcium XI Plasma thromboplastin antecedent

V Proaccelerin XII Hageman factor


obstetrics

1-Antithrombin III (ATnativ, Thrombate III):

Used for moderately severe–to– severe DIC or when levels are depressed markedly.

2-Recombinant human activated protein C:

These agents inhibit factors Va and VIIIa of the coagulation cascade. They may

also inhibit plasminogen activator inhibitor-1 (PAI-1).

Blood components

Blood components are used to correct abnormal hemostatic parameters. These

products should be considered only after initial supportive and anticoagulant

therapy. Washed PRBCs and platelet concentrates are considered safe in

uncontrolled DIC.1 unit of PRBCs should raise hemoglobin by 1 g/dL or raise hematocrit by 3%.

Platelet concentrates Considered safe for use in acute DIC.



9/29

obstetrics

Fresh frozen plasma (FFP) Contains coagulation factors as well as protein C and protein S. Recommended with active bleeding and fibrinogen <100 mg/dL.

Anti ibrinol tica ents

These agents are used only after all other therapeutic modalities have been tried anddeemed unsuccessful. Increase in circulating plasmin and laboratory evidence of decreased plasminogen should be documented. Antifibrinolytics may be useful incases of DIC secondary to hyperfibrinolysis associated with acute promyelocyticleukemia and other forms of cancer.

Related to the use of activated protein C is the recent utilization of protein Cconcentrate to treat coagulation abnormalities in adult patients with sepsis. ProteinC concentrate was found to be safe and useful in restoring coagulation andhematologic parameters. Further study is required and prospective evaluation of its

.

-Baratto F, Michielan F, Meroni M, Dal Palu A, Boscolo A, Ori C. Protein C concentrate to restore physiological values inadult septic patients.Intensive Care Med. Sep 2008;34(9):1707-12. [Medline].

obstetrics

In conclusion

The outcome of high risk patients can be dramatically improved if :

Good peripartum care

The presence of anesthesiologist from the first moment the patient is

admitted

Good co-operation and harmony between the anesthesiologist andthe obstetrician and the hematologist

Reasonable level of facilities and drugs.


I Fibrinogen VIII Antihemophilic factor



IV Calcium XI Plasma thromboplastin antecedent

V Proaccelerin XII Hageman factor




9/29

Thank you

anesthetic mngt -high risk obg pts

Documents