Dr. Krushna Patel

Postgraduate, MEM

KDAH, Mumbai

17-07-2012

RESUSCITATION IN PREGNANCY

GOALS

1. To understand and perform basic and advance life support in pregnant patients

2. Understand the adaptations of CPR

3. Understand the importance of early defibrillation when appropriate

4. Understand the need to perform perimortem cesarean section

SCOPE OF THE PROBLEM

According to the Confidential Enquiries into Maternal And Child Health (CEMACH) overall maternal mortality rate is 13.95deaths/100,000 maternities (AHA

CIRCULATION :2010)

Out of which 8 are due to cardiac arrest with frequency of 0.05 per 1000 maternities or 1:20,000

Rescuers must provide appropriate resuscitation based on consideration of physiological changes caused by pregnancy.

ANATOMICAL AND PHYSIOLOGICAL CHANGES IN PREGNANCY

CARDIOVASCULAR SYSTEM

Uteroplacental blood flow

Maternal blood volume Arterial pressure

Cardiac output Increases 30 – 45%

20th week of gestation

Maternal heart rate

increases 10- 15 beats/min

SBP and DBP First two trimesters – decreases by 10 – 15 mm hg

Returns to baseline by term

Supine pregnant patient

Gravid uterine pressure

Compression of IVC

Decreased venous return

Decreased cardiac output – 10 – 30%

Poor venous flow

Compromises infradiaphragmatic i.v sites

Femoral / saphenous routes

Not recommended for i.v access

During resuscitation

RESPIRATORY SYSTEM

Increased Tidal Volume

Progesterone stimulated

hyperventilation

Increased minute ventilation

Chronic respiratory

alkalosis

Decreased Functional Residual

Capacity – 20%

Rapid decrease in arterial

oxygen content during arrest

Right side shift of oxyhemoglobin curve during arrest state

Maintain maternal PO2 of >60 mm hg

in arrest state

Delayed Gastric emptying in pregnancy

(progesterone like effects of placental hormones)

Increased acidity of stomach contents

cardiac sphincter relaxation causes

regurgitation of stomach contents

Increased chance of aspiration and vomiting

GASTO-INTESTINAL SYSTEM

AIRWAY AND VENTILATION CONSIDERATION IN PREGNANCY

Decreased tolerance for hypoxia and apnoea

Tongue, mucosa, supraglottic edema & friability

Difficult mask ventilation• Low FRC• Elevated diaphragm• Raised intra-abdominal pressure

Mallampatti class 3 airway

Weight gain & obesity• Increased neck folds• Foreshortened neck

Increased risk of aspiration• Increased gastric emptying time• Decreased lower esophageal sphincter tone

KEY INTERVENTIONS TO PREVENT ARREST

Place the patient in the full left-lateral position to relieve possible compression of the inferior vena cava. Uterine obstruction of venous return can produce hypotension and may precipitate arrest in the critically ill patient.

Give 100% oxygen.

Establish intravenous (IV) access above the diaphragm.

Assess for hypotension : maternal hypotension that warrants therapy has been defined as a systolic blood pressure 100 mm Hg or 80% of baseline.

Maternal hypotension can result in reduced placental perfusion.

In the patient who is not in arrest, both crystalloid and colloid solutions have been shown to increase preload.

Consider reversible causes of critical illness and treat conditions that may contribute to clinical deterioration as early as possible.

RESUSCITATION OF THE PREGNANT PATIENT IN CARDIAC ARREST MODIFICATIONS OF CARDIOPULMONARY

RESUSCITATION

Patient Positioning

Important strategy to improve the quality of CPR and resultant compression force and output.

The pregnant uterus especially of >20 weeks gestation or gravid uterus palpated above the umbilicus, compresses the inferior vena cava, impeding venous return and thereby reducing stroke volume and cardiac output.

In non cardiac arrest parturients left-lateral tilt results in improved maternal hemodynamics of blood pressure, cardiac output, and stroke volume and improved fetal parameters of oxygenation, nonstress test, and fetal heart rate.

Left lateral tilt - 30 degrees using wedge (hard) of predetermined angle. Eg. Cardiff wedge

Manual left uterine displacement, with the patient in supine, also relieves aortocaval compression .

Left uterine displacement - patient’s left side with the 2-handed technique

The patient’s right side with the 1-handed technique , depending on the positioning of the resuscitation team.

If chest compressions remain inadequate after lateral uterine displacement or left-lateral tilt, immediate emergency cesarean section should be considered.

BLS AND ACLS MODIFICATIONS

AIRWAY AND BREATHING

Active airway management is the initial consideration.

Airway management is more difficult during pregnancy

Secure airway early in resuscitation

OPTIMAL use of bag-mask ventilation and suctioning, while preparing for advanced airway placement should be done

Use small endotracheal tubes, short laryngoscope handles

Use an ETT 0.5 to 1 mm smaller in internal diameter than that used for a nonpregnant woman of similar size because the airway may be narrowed from edema

Give 100 % oxygen and mainatain good saturation

CIRCULATION

Chest compressions should be performed slightly higher on the sternum than normally recommended to adjust for the elevation of the diaphragm and abdominal contents caused by the gravid uterus.

Position is slightly above the centre of the sternum

Current recommended drug dosages for use in resuscitation of adults can also be used in resuscitation of the pregnant patient in cardiac arrest.

DEFIBRILLATION

Management of ventricular arrhythmias require defibrillation during maternal resuscitation.

There should be no delay if use of defibrillation is indicated

Energy levels are same as ACLS protocol

Before delivering the shock, REMOVE FETAL MONITORING EQUIPMENTS to prevent electrocution injury to patient or rescuer

PREGNANCY-RELATED CAUSES OF MATERNAL CARDIOPULMONARY ARREST

B- Bleeding(haemorrhage)/ DIC

E- Embolism/coronary/pulmonary/amniotic fluid embolism

A- anesthetic complications

U- Uterine atony

C- Cardiac diseases/MI/Ischemia/aortic dissection/cardiomyopathy

H- Hypertension / Preclampsia/ Eclampsia

O- Others / Diff. Diag of standard ACLS guidelines i.e 5H’s and 5T’s

P- Placenta previa/ Abruptio placenta

S- Sepsis

REVERSIBLE CAUSES

Electrolyte abnormalities Tamponade Hypothermia

Hypovolemia Hypoxia Hypomagnesemia

Myocardial infarction

Pulmonary embolism

Tension pneumothorax

HAEMORRAGE

Case of placenta previa/ abruptio placenta, where bleeding is significant

Fluid resuscitation with RL/ NS

Vasopressor agent - Inj. Ephedrine (5mg every 5 mins till response is seen) , if fluids fail to restore adequate blood pressure.

EMBOLISM

Pulmonary embolism• Thromboembolic disease risk

increased• Hypoxic/ hemodynamic unstable• Anticoagulation with heparin –

currently the treatment of choice• Also , adequate oxygenation and

treating hypotension• Elevated D-dimer not a helpful

screen in pregnancy• CT scan or VP scan to confirm

diagnosis on treatment is stated.• Use of thrombolytics reserved when

potential benefits outweighs the risks, emergencies beyond 20 wks gestation, postpartum period

Amniotic fluid embolism

• Dyspnoea, hypotension associated with pt. is labour/ abortion

• Sudden onset breathlessness, air hunger, decreased oxygen saturtion

• Develop cardiac arrest within minutes

• DIC• Multi- organ failure• Treatment tried : cardiopulmonary

bypass, open pulmonary artery thromboembolectomy.

ANESTHETIC COMPLICATION

Bupivacaine induced arrythmia – amiodarone is the primary drugin the ACLS arrythmia algorithm.

Early administration of lipid emulsification (20% intralipid) – used in resuscitation of bupivacaine- induced cardiotoxicity. ( lipid rescue therapy : picard J . Anesthesia 2009)

CARDIAC DISEASE

The most common causes of maternal death from cardiac disease are myocardial infarction, followed by aortic dissection.

Women deferring pregnancy to older ages, increases the chance of having atherosclerotic heart disease.

Fibrinolytics is relative contraindication in pregnancy

PCI is the reperfusion strategy of choice for ST-elevation myocardial infarction.

illnesses related to congenital heart disease and pulmonary hypertension are the third most common cause of maternal cardiac deaths.

PREECLAMPSIA/ECLAMPSIA

Preeclampsia/eclampsia develops after the 20th week of gestation and can produce severe hypertension and ultimately diffuse organ-system failure.

Magnesium sulphate

If untreated, maternal and fetal morbidity and mortality results.

MAGNESIUM SULFATE TOXICITY

Magnesium toxicity present with ECG interval changes: (prolonged PR, QRS and QT intervals) at magnesium levels of 2.5–5 mmol/L

AV nodal conduction block, bradycardia, hypotension and cardiac arrest at levels of 6–10 mmol/L.

Neurological effects : loss of tendon reflexes, sedation, severe muscular weakness, and respiratory depression are seen at levels of 4–5 mmol/L.

Others include: gastrointestinal symptoms (nausea and vomiting), skin changes (flushing), and electrolyte/ fluid abnormalities (hypophosphatemia, hyperosmolar dehydration).

Patients with renal failure and metabolic derangements can develop toxicity after relatively lower magnesium doses.

Iatrogenic overdose is possible in the pregnant woman who receives magnesium sulfate, particularly if the woman becomes oliguric.

Administration of calcium gluconate (10 ml of a 10% solution) is the treatment of choice

Empiric calcium administration may be lifesaving

Trauma and drug overdose

Pregnant women are not exempt from the accidents & mental illnesses

Domestic violence also increases during pregnancy; homicide & suicide are one of the causes of mortality during pregnancy

EMERGENCY CESAREAN SECTION IN CARDIAC ARREST

Delivery of the foetus is a part of resuscitation process when applicable.

Despite appropriate modifications – mechanical effect of gravid uterus – decreases venous return from IVC – obstructs blood flow through abd. aorta – decreases thoracic compliance – unsuccessful CPR – increased risk of hypoxia going in for anoxia to mother and foetus BEYOND 4 MINUTES OF ARREST.

WHY PERFORM AN EMERGENCY CESAREAN SECTION IN CARDIAC ARREST?

Emergency cesarean section in maternal cardiac arrest indicate a return of spontaneous circulation or improvement in maternal hemodynamic status only after the uterus has been emptied.

Recent studies indicates ROSC and maternal hemodynamic stability of the mother and normal neurological outcome of the neonate post perimortem casarean.

The critical point to remember is that both mother and infant may die if the provider cannot restore blood flow to the mother’s heart.

THE IMPORTANCE OF TIMING WITH EMERGENCYCESAREAN SECTION

When the maternal prognosis is grave and resuscitative efforts appear futile, moving straight to an emergency cesarean section may be appropriate, especially if the fetus is viable.

If emergency cesarean section cannot be performed by the 5-minute mark, it may be advisable to prepare to evacuate the uterus while the resuscitation continues.

DECISION MAKING FOR EMERGENCY CESAREAN DELIVERY

Gestational age less than 20 weeks

Need not be considered because this size gravid uterus is unlikely to significantly compromise maternal cardiac output

Gestational age approximately 20 to 23 weeks

Perform to enable successful resuscitation of the mother, not the survival of the delivered infant, which is unlikely at this gestational age

Gestational age greater than 24 weeks

Perform to save the life of both the mother & infant

The following can increase the infant’s survival:

Short interval between the mother’s arrest & the infant’s delivery

Perimortem caesarean section to be performed within 4 mins of cardiac arrest and delivery of the foetus within 5 mins.

No sustained pre arrest hypoxia in the mother

Minimal or no signs of fetal distress before the mother’s cardiac arrest

Aggressive & effective resuscitative efforts for the mother

Delivery to be performed in a medical center with easy access to NICU.

PERIMORTEM CESAREAN SECTION

Prognosis for intact survival of infant is best if delivered within 5 mins of maternal arrest.

Goal : to remove foetus and continue resuscitation of both mother and foetus

During the procedure maternal CPR has to be continued.

Vertical midline abdominal incision from 4 -5 cm below xiphoid process to pubic symphysis

Incise through the fascia and muscles into the peritoneum

Vertical uterine incision .

Delivery of the fetus

Manual removal of placenta and its membranes.

Closure of abdomen may be delayed until maternal blood pressure and pulse is restored.

Dilute oxytocin 10 units in 9 ml NS to prevent uterine atony.

INFORMED CONSENT FOR PERIMORTEM CS IS NOT NECESSARY

POST–CARDIAC ARREST CARE

Post–cardiac arrest hypothermia can be used safely and effectively in early pregnancy without emergency cesarean section (with fetal heart monitoring), with favorable maternal and fetal outcome after a term delivery.

No cases in the literature have reported the use of therapeutic hypothermia with perimortem cesarean section.

Therapeutic hypothermia may be considered on an individual basis after cardiac arrest in a comatose pregnant patient based on current recommendations for the nonpregnant patient

During therapeutic hypothermia of the pregnant patient, it is recommended that the fetus be continuously monitored for bradycardia as a potential complication, and obstetric and neonatal consultation should be sought

SUMMARY

Successful resuscitation of a pregnant woman & survival of the fetus require prompt & excellent CPR with some modifications in techniques

By the 20th week of gestation, the gravid uterus can compress the IVC & aorta, obstructing venous return & arterial blood flow

Rescuers can relieve this compression by positioning the woman on left side or by pulling the gravid uterus to the side

Defibrillation & medication doses used for resuscitation of the pregnant woman are the same as those used for other adults

Rescuers should consider the need for ER Caesarian Delivery as soon as the pregnant woman develops cardiac arrest

Rescuers should be prepared to proceed if the resuscitation is not successful within 4 minutes

SEQUENCE FOR CPR IN PREGNANT PATIENTS

Intubate early

Protect vulnerable airway

Supply oxygen

Tilt the patient

Limit aortocaval compression

Obtain rapid IV access, avoid the femoral and saphenous veins

Follow current ACLS recommendations

Perimortem cesarean section within 5 min of maternal arrest if fetus >20 wk

Consider open chest CPR within 15 min of maternal arrest

Explore differential diagnosis, include iatrogenic causes (e.g., spinal analgesia). Consider cardiopulmonary bypass, if indicated.

REFRENCES

COURTESY : UPDATE JUNE 2012 LITERATURE REVIEW

AHA : CIRCULATION 2010 – CARDIAC ARREST IN PREGNANCY

TINTINALLI 7TH EDITION

THANK YOU