RESUSCITATION IN PREGNANCYDr. Krushna PatelPostgraduate, MEMKDAH, Mumbai17-07-2012
GOALS1. To understand and perform basic and advance life support in pregnant patients2. Understand the adaptations of CPR3. Understand the importance of early defibrillation when appropriate4. Understand the need to perform perimortem cesarean section
SCOPE OF THE PROBLEMAccording 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 1:20,000Rescuers must provide appropriate resuscitation based on consideration of physiological changes caused by pregnancy.
ANATOMICAL AND PHYSIOLOGICALCHANGES IN PREGNANCYCARDIOVASCULAR SYSTEM Uteroplacental Maternal blood volume Arterial blood flow pressure Increases 30 – 20th week of Cardiac output 45% gestation Maternal heart increases 10- 15 beats/min rate First two trimesters – Returns to SBP and DBP decreases by 10 – 15 mm hg baseline by term
Poor venous flow Compromises infradiaphragmatic i.v sitesFemoral / saphenous routes Not recommended for i.v access During resuscitation
RESPIRATORY SYSTEM ProgesteroneIncreased Tidal stimulated Increased minute Volume hyperventilation ventilation Decreased Rapid decrease Chronic Functional in arterial respiratory Residual oxygen content alkalosis Capacity – 20% during arrest Right side shift of Maintain maternal oxyhemoglobin PO2 of >60 mm hg curve during in arrest state arrest state
GASTO-INTESTINAL SYSTEMDelayed Gastric emptying in pregnancy Increased acidity of(progesterone like effects stomach contents of placental hormones) cardiac sphincter Increased chance of relaxation causes aspiration and vomitingregurgitation of stomach contents
AIRWAY AND VENTILATION CONSIDERATION IN PREGNANCYDecreased tolerance for hypoxia and apnoeaTongue, mucosa, supraglottic edema & friabilityDifficult mask ventilation • Low FRC • Elevated diaphragm • Raised intra-abdominal pressureMallampatti class 3 airwayWeight gain & obesity • Increased neck folds • Foreshortened neckIncreased 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 PREGNANTPATIENT IN CARDIAC ARREST MODIFICATIONS OF CARDIOPULMONARY RESUSCITATIONPatient 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.
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. Thereshould 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 MATERNALCARDIOPULMONARY ARRESTB- Bleeding(haemorrhage)/ DICE- Embolism/coronary/pulmonary/amniotic fluid embolismA- anesthetic complicationsU- Uterine atonyC- Cardiac diseases/MI/Ischemia/aortic dissection/cardiomyopathyH- Hypertension / Preclampsia/ EclampsiaO- Others / Diff. Diag of standard ACLS guidelines i.e 5H’s and 5T’sP- Placenta previa/ Abruptio placentaS- Sepsis
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 Amniotic fluid embolism• Thromboembolic disease risk • Dyspnoea, hypotension associated increased with pt. is labour/ abortion• Hypoxic/ hemodynamic unstable • Sudden onset breathlessness, air• Anticoagulation with heparin – hunger, decreased oxygen saturtion currently the treatment of choice • Develop cardiac arrest within• Also , adequate oxygenation and minutes treating hypotension • DIC• Elevated D-dimer not a helpful • Multi- organ failure screen in pregnancy • Treatment tried : cardiopulmonary• CT scan or VP scan to confirm bypass, open pulmonary artery diagnosis on treatment is stated. thromboembolectomy.• Use of thrombolytics reserved when potential benefits outweighs the risks, emergencies beyond 20 wks gestation, postpartum period
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 DELIVERYGestational age less than 20 weeks Need not be considered because this size gravid uterus is unlikely to significantly compromise maternal cardiac outputGestational 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 ageGestational 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 arrestExplore 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