The association of obstetric anesthesiologists, India – An expert committee consensus statement and recommendations for the management of maternal cardiac arrest
Sunil T Pandya1, Kajal Jain2, Anju Grewal3, Ketan S Parikh4, Karuna Sharma5, Anjeleena K Gupta6, Shilpa Kasodekar7, Aruna Parameswari8, Daisy Gogoi9, Lalit K Raiger10, Gonibeed Lakshminarayana Rao Ravindra11, Sunanda Gupta12, Anjan Trikha13
1 Chief, Deptt of Anesthesia, Perioperative Medicine and Critical Care, AIG Hospitals and Fernandez Hospitals, Hyderabad, Telangana, India
2 Professor, Anesthesia and Intensive Care, PGIMER, Chandigarh, India
3 Professor and Head, Department of Anesthesiology, Dayanand Medical College and Hospital, Ludhiana, Punjab, India
4 Consultant Anesthesiologist, Breach Candy Hospital and Research Centre, Mumbai, Maharashtra, India
5 Assoicate Professor, Department of Anesthesia, Geetanjali Medical College and Hospital, Udaipur, Rajasthan, India
6 Senior Consultant, Institute of Anesthesiology, Pain and Perioperative Medicine, Sir Ganga Ram Hospital, New Delhi, India
7 Chief Anesthesiologist, Department of Anesthesia, PD Hinduja Hospital, Khar, Mumbai, Maharashtra, India
8 Professor and Head, Department of Anesthesiology, Critical Care and Pain Medicine, Sri Ramachandra University, Chennai, India
9 Chief Anesthesiologist, Department of Anesthesia & Perioperative Care, Pratiksha Hospital, Guwahati, India
10 Senior Professor, Anesthesiology & Principal, Government Medical College & Hospitals, Sirohi, Rajasthan, India
11 Chief Consultant Anesthesiologist, Janani Anesthesia and Critical Care Services, Shimoga, Karnataka, India
12 Professor Emeritus, Geetanjali Medical College and Hospital, Udaipur, Rajasthan, India
13 Department of Anesthesia and Perioperative Care, School of Medicine, University of California, San Francisco, USA
Correspondence Address:
Dr. Sunanda Gupta
Professor Emeritus, Geetanjali Medical College and Hospital, Udaipur, Rajasthan
India
Source of Support: None, Conflict of Interest: None
CheckDOI: 10.4103/JOACC.JOACC_44_22
Maternal cardiac arrest (MCA) requires a multidisciplinary team well versed in the cascade of steps involved during resuscitation. Historically, maternal outcomes were poor, primarily because cardiac arrest management in pregnant women was neither optimum nor standardized. However, current evidence has shown better maternal survival given the young age and reversible causes of death. There are specific interventions such as manual left uterine displacement (MLUD) for relief of aortocaval compression that, if not performed, may undermine the success of resuscitation. The team should simultaneously explore the etiology of MCA, which could be a combination of pregnancy-related causes and comorbid conditions. Resuscitative Hysterotomy or Resuscitative Uterine Interventions (RUI) should be considered if there is no return of spontaneous circulation following 4–5 min of cardiopulmonary resuscitation. Teamwork is critical to success in the high-stakes environment of MCA. This consensus statement was prepared by the experts after reviewing evidence-based literature on maternal resuscitation during MCA.
Keywords: Manual left uterine displacement, maternal cardiac arrest, resuscitative hysterotomy
Maternal mortality is recognized as a major global public health issue. Maternal cardiac arrest (MCA) has been reported to occur in 1 in 12,000 hospital admissions for childbirth in the USA,[1] 1 in 12,500 in Canada,[2] 1 in 36,000 pregnant women in the Cardiac Arrests in Pregnancy (CAPS) study from the UK,[3] and 1:3885 from a developing country such as Taiwan.[4] However, higher survival rates have been reported in a series of reports from the United States of America, Canada, and the United Kingdom as 58.9, 71.3, and 58%, respectively.[1],[3],[5] In developing countries such as India, there is paucity of reliable maternal registry and, hence, there is uncertainty regarding the exact incidence of MCA.
Perimortem cesarean delivery (PMCD) had a connotation of a feto-centric approach to optimize neonatal outcomes following cardiopulmonary arrest. This was later renamed as resuscitative hysterotomy (RH), which, as the name implies, is a resuscitative surgical maneuver on the uterus to deliver the fetus.[6],[7] Consequently, the expert panel from the Association of Obstetric Anesthesiologists (AOA) India suggested that it should be rephrased as “resuscitative uterine interventions” (RUI), as it encompasses RH to evacuate the uterus, and if clinically deemed necessary, co-interventions may be performed, commensurate to the underlying cause, expertise, and facilities available at the health care facility.
This consensus statement from the AOA, India provides an evidence-based algorithmic approach to managing MCA for best maternal outcomes [Figure 1]. The committee members have deliberated at length on the guidelines suggested by international bodies, such as American Heart Association,[8] Society of Obstetric Anesthesia and Perinatology,[9] Obstetric Anesthesia Association UK,[10] European Resuscitation Council guidelines,[11] and Royal College of Obstetricians and Gynecologists guidelines.[12] An electronic search was also done for full-text articles published in the English language before February 2022 after formulating a list of MCA-related search terms using PubMed, EMBASE, Google scholar database, Ovid, and Cochrane Library. Meta-analysis, systematic reviews, randomized controlled trials, observational studies, cohort studies, case series, and reports were included, while editorials, narrative reviews, correspondence, and letters to the editors were excluded.
Basic Life Support
Basic life support comprises simultaneous and coordinated interventions implemented immediately depending on available resources. Early activation of an emergency team, also called as the maternal code blue team, should be activated as soon as unresponsiveness is established while ensuring scene safety. The maternal code blue team ideally comprises an adult resuscitation team that includes physician/surgeon/nurses (according to local institutional policy) and an obstetric resuscitation team (an obstetrician and labor room nurse, anesthesia care providers, and neonatology team [physician, neonatologist, and nurse]). In health care setting without obstetric and neonatology services, lead physicians should designate trained health care providers for maternal resuscitation. The cardiac arrest team leader should delegate specific roles for airway management, obstetric and neonatal care.[8] Resuscitation measures include placement of a firm back support, high-quality chest compressions, airway management, defibrillation when indicated, and manual left uterine displacement (MLUD). These steps should be done simultaneously by in-hospital health care providers (minimum four in number) at the location of cardiac arrest and reinforced by the maternal code blue team after arrival. In out-of-hospital MCA, Cardiopulmonary resuscitation (CPR) using only chest compressions with MLUD should be initiated immediately. First responder providers should simultaneously begin bag mask ventilation with 100% oxygen. A two-hand or four-hand technique of bag mask ventilation is a useful method to manage airway and breathing till experienced airway providers reach the site of maternal arrest. Compression-ventilation ratio of 30:2 should be commenced, and all attempts should be made to minimize interruptions in chest compressions so as to devote 60–80% of time for high-quality chest compressions. If mask ventilation does not produce a visible chest rise, the provider must attempt to optimize head neck tilt and ensure a tight face mask seal. Use of an oral airway or if needed a laryngeal mask airway may help to overcome ineffective ventilation.[13],[14],[15]
Patient PositioningThe patient should preferably be placed supine on a firm, hard surface.[16],[17],[18],[19],[20],[21],[22],[23] Air-filled mattresses should be flattened while performing chest compressions.[19],[20],[21],[22],[23] MLUD should be performed by using one or two hands [Figure 2] and [Figure 3]. The uterus should be cupped and lifted leftward and upward, away from the abdominal aorta and the inferior vena cava, to prevent any downward force leading to compression of the great vessels. MLUD minimizes the adverse effects of aortocaval compression on venous return and cardiac output. It is mandatory for effective CPR, if the gestational age is >20 weeks or if the fundus of uterus is above the level of umbilicus.[24],[25],[26],[27]
Figure 2: Manual left uterine displacement, single-hand technique (rescuer on right side) arrow showing direction as leftwardsFigure 3: Manual left uterine displacement, two-hand pull (rescuer on left side) arrows showing directions as upwards and leftwards Chest CompressionsTo perform chest compressions, the rescuer should place heel of one hand on the center of the lower half of sternum. The heel of the other hand should be placed on top of the first hand, so that the hands overlap. Continuous chest compressions with a compression: ventilation ratio of 30:2, should be performed at a rate of at least 100 per minute, at a depth of at least 2 inches (5 cm), allowing full recoil before the subsequent compression. Interruptions should be minimal and limited to 10 seconds for specific interventions such as insertion of an advanced airway or use of a defibrillator.[8]
Recommendations:
Early activation of maternal code blue team.Keep patient supine for chest compressions and use a firm backboard.Perform continuous MLUD.High–quality chest compression only CPR, till help arrives, especially in out of hospital scenario.Hand position should be at lower half of sternum as in non-pregnant population.Compression-ventilation ratio 30:2 at 100/min, at a depth of at least 2 inches (5 cm) with minimum interruptions limited to <10 sec.Not Recommended
A tilt of the bed/board 30° to the left of the patient is not recommended. Left lateral tilt can shift the heart more laterally, thereby interfering with pump mechanism during chest compression, making them much less effective and, hence, defeats the goal of preserving venous return. Ensuring adequate venous return while optimizing force vectors is vital to generating effective chest compressions.
DefibrillationShockable rhythms are infrequent in pregnant women (approximately 10%).[5] However, defibrillation should be performed as early as possible whenever a shockable rhythm is detected. Energy delivered is the same as that for non-pregnant women as the electrical impedance of the thorax remains the same. The shock energy may minimally pass to fetus and is considered safe at all stages of pregnancy,[28],[29] hence fetal monitors must be removed only if this does not delay shock delivery. A biphasic shock energy of 120–200 J should be used for defibrillation, with subsequent increase of energy output if the first shock is ineffective and the device permits this option. Adhesive pads/paddles should be placed above the right breast and anterolateral pad/paddles underneath the left breast, a crucial consideration in the parturient. Compressions should begin immediately after defibrillation. An automated external defibrillator should be kept in areas where defibrillators are used infrequently or medical staff have poor rhythm recognition skills (e.g., labor room), so that defibrillation can be given immediately.
Recommendations:
Defibrillation for shockable rhythms such as pulseless ventricular tachycardia and ventricular fibrillation should be performed early to achieve Return of Spontaneous Circulation (ROSC).There is no change in thoracic impedance in pregnancy, so energy requirements are the same as in non-pregnant women.Defibrillation should not be delayed to remove external or internal fetal monitors, for theoretical risk of burns.Automated external defibrillator should be available on all floors in the hospital. Advanced Life SupportEnsure high-quality chest compressions with the preferred use of either end-tidal carbon dioxide (EtCO2) or a real-time feedback device. In addition, the provider assigned for defibrillation can position himself or herself right across the compressor to provide visual real-time feedback further aiding in improving chest compression fraction to more than 60%. Establish a definitive airway promptly to prevent aspiration and minimize interruptions in chest compressions. The incidence of failed intubation during pregnancy has been reported to be 1/250 vs. 1/2000 in non-pregnant women. A difficult airway is to be expected in pregnant women even during CPR.[30],[31] A decreased functional residual capacity and increased oxygen consumption make adequate and effective oxygenation challenging in MCA. Oral endotracheal intubation is preferred with smaller sized cuffed endotracheal tube (6–7 mm internal diameter), as vascular engorgement results in edema of the upper airway, causing narrowing and more chances of bleeding. Thus, an experienced anesthesiologist should perform endotracheal intubation.
Chest compressions should be given at the rate of 100/min for 2 min and breaths should be delivered at the rate of 8-10 /min with 100% oxygen, without synchronization whenever a definitive airway is secured. A second-generation supraglottic airway device with a gastric drain tube may be preferred, if an endotracheal tube cannot be successfully placed within two optimized attempts. An emergency front of neck airway access (e.g. percutaneous scalpel bougie cricothyroidotomy) should be promptly performed in an event of failure to ventilate using either face mask, supraglottic device or endotracheal tube.[32],[33],[34] Multiple prolonged attempts at laryngoscopy and intubation should be avoided to prevent deoxygenation, interruptions in chest compressions, and airway trauma. Cricoid pressure is not routinely advised.[35],[36]
CapnographyContinuous waveform capnography is the ideal way of confirming and monitoring the correct placement of the endotracheal tube. Best practice recommendations mandate monitoring CPR quality using End tidal carbondioxide (EtCO2), for optimizing chest compressions and early detection of ROSC. Findings consistent with high-quality chest compressions are an EtCO2 level more than 10 mmHg or an abrupt sustained rise of EtCO2 >35–40 mmHg suggesting ROSC.[37],[38],[39],[40],[41]
Recommendations:
Experienced anesthesiologist should perform intubation as airway of pregnant patients is deemed to be difficult.A smaller size cuffed endotracheal tube (6-7mm inner diameter) should be used for endotracheal intubation. A second-generation laryngeal mask airway should be used as a rescue device.Bag mask ventilation using two-hand technique should be performed till definitive airway is secured.Continuous monitoring of end tidal carbon dioxide is recommended.Identify the cause of arrest, using a Mnemonic ABCDE-UPS.A - Anaphylaxis, Anesthetic causes
B - Bleeding (Coagulopathy, Trauma, Transfusion reaction, Intracranial or Hepatic bleed)
C - Cardiovascular causes
D - Drugs (MgSO4, Medication errors)
E - Eclampsia, Embolism (Amniotic / Air)
U - Uterine causes (Placenta accreta spectrum, Abruptio, Rupture)
P - Pulmonary causes (Venous Thromboembolism, Respiratory Failure, Pulmonary edema)
S - Sepsis
MedicationsAlthough the physiologic changes of pregnancy affect drug metabolism, volume of distribution and drug clearance, dosages of drugs administered during cardiac arrest are not changed. Institution of intravenous (IV) access is generally preferred above the diaphragm because of impeded venous return secondary to aortocaval compression. Intraosseous access can be obtained in cases where IV access is not immediately available
Drugs Adrenaline: IV epinephrine 1 mg every 3–5 min is the vasopressor of choice.Amiodarone: Amiodarone (300 mg rapid infusion and repeat doses of 150 mg) should be given in ventricular fibrillation or pulseless ventricular tachycardia that is unresponsive to CPR, defibrillation, and epinephrine.[42]Lipid rescue: To manage cardiac arrest following Local Anesthetic Systemic Toxicity (LAST), high-quality chest compressions must be complemented with a bolus dose of lipid emulsion 20% 1.5 ml/kg over 1 min. It should be followed by an IV infusion of Intralipid 20% at 15 ml/kg/h. Lipid emulsion can be repeated twice at 5-min intervals not exceeding 12 ml/kg, if ROSC is not achieved.[43],[44],[45] If LAST is refractory to standard resuscitative measures, cardiopulmonary bypass or extracorporeal membrane oxygenation (ECMO) may be contemplated if facilities are available.[43]Calcium gluconate / chloride: Respiratory depression occurs in 1–8% of pregnant women receiving magnesium infusion with preeclampsia, which may occur without loss of tendon reflexes.[7] Calcium gluconate / chloride is the antidote for magnesium toxicity. Discontinue MgSO4 infusion and administer 10ml of 10% Calcium gluconate /chloride by slow IV injection in case of Magnesium toxicity.[46]For anaphylaxis, all possible causative agents should be removed, and resuscitation should be followed as per guidelines. Once diagnosed, treatment should include escalating doses of 50 μg epinephrine bolus (0.5 ml 1:1000 solution) IV along with adjuvant therapy such as hydrocortisone 200 mg and chlorpheniramine 10 mg (slow IV).[47],[48]Supplementary medications that may be used during MCA include insulin, oxytocin, and opioids.Uterotonic drugs: Oxytocin is a vasodilator and if administered in high bolus doses of 5–10 U may lead to cardiovascular collapse and re-arrest post ROSC, hence judicious use is advocated.[49],[50]Neuraxial opioids or IV opioids (mu agonists such as fentanyl, morphine, sufentanil, etc.) can cause respiratory depression and arrest, which should be treated with naloxone 0.4 mg intravenously as bolus and repeated after 15 min, if there is no response. If respiratory depression is because of the long-acting narcotic agents such as morphine, naloxone bolus dose should be followed by infusion (0.2–0.6 mg/h).[51]Tranexamic acid: WHO strongly recommends use of tranexamic acid intravenously (within 3 h of birth) in all cases of postpartum hemorrhage in a fixed dose of 1 g at 1 ml/min with a second dose if bleeding continues after 30 min, or if bleeding restarts after 24 h of first dose.[52]Recommendations:
Follow Advanced Cardiac Life Support (ACLS) algorithm as per the initial rhythm detected.IV access should be placed routinely above the diaphragm. An intraosseous access should be considered where IV access cannot be obtained.LAST guidelines should be available in all labor suites.Intralipid, calcium chloride, and other emergency drugs should be available in crash carts of labor room.Tranexamic acid 1 gm intravenous should be given if bleeding occurs. Resuscitative Uterine Interventions (RUI) or Perimortem Cesarean Delivery (PMCD)RUI or PMCD or RH [Figure 4] encompasses operative interventions in MCA performed at the site of cardiac arrest, usually when ROSC has not occurred within 5min of maternal resuscitation. RUI includes operative delivery of the fetus from the uterus, uterine compression sutures, hysterectomy, or other additional interventions commensurate to the underlying cause, expertise and facilities available at the healthcare setting. RH performed at <5min vs >5min, has shown an improvement in maternal survival at 61% vs 35% and neonatal survival at 96% vs 70%.[3]
The benefits of RUI include improved venous return and cardiac output, following release of aortocaval compression, decrease in oxygen consumption, and improvement in pulmonary mechanics in the mother; while neonatal outcomes are improved as risk of neurological damage because of hypoxia is avoided.[3]
RUI should be performed at the site of arrest instead of transporting the arrested patient to the operation room as attention to core tasks and high-quality chest compressions may be compromised. On site RUI is found to improve maternal survival (72% vs. 36%) compared to transfer to the operation theater (OT).[53]
Equipment required during RUI should be kept to a bare minimum such as a scalpel, which should be immediately available. Ideally, a RUI tray should be available at all strategic locations that includes, scalpel, retractor, forceps, sponges, needle holder, sutures, and scissors.[8] Access to vascular clamps is advocated, considering the increasing incidence of placenta accreta spectrum cases, which may lead to obstetric hemorrhage following ROSC. A very abbreviated antiseptic cleaning should be performed, a vertical incision is advisable, however, the surgeon's comfort with the technique should take precedence. During the procedure, left uterine displacement (till delivery occurs) and high-quality resuscitative efforts should be continued.[54]
If ROSC occurs after RUI at the site of arrest, patient should be transported to OT/ICU after hemodynamic stabilization for further post resuscitation care management. However, if ROSC occurs before delivery, then patient should be transported to OT, with a standby team ready to perform cesarean delivery, and subsequent transfer to the ICU on improvement of maternal status. Targeted temperature management after ROSC has been advocated in pregnant women.[20],[21],[22]
Recommendations:
In case there is a failure to achieve ROSC following 5 min of CPR, RH / RUI should be considered in gestational age >20 weeks.If the cardiac arrest occurs within the hospital, an on-site RUI should be done instead of transferring the patient to the OT.Emergency RUI includes an abbreviated antiseptic preparation of surgical site.The surgical team should not delay surgery for want of sophisticated surgical equipments and should start with a scalpel.During RUI, continuous resuscitation and MLUD should be maintained.An RUI surgical tray, should also include vascular clamps, considering the increased incidence of PAS, which may lead to hemorrhage following ROSC. Post Cardiac Arrest CareA multidisciplinary team should care for the patient in the post arrest period depending on whether ROSC has occurred before or after delivery of the baby. If the patient is post-delivery and if there is a failure to achieve ROSC, then ECMO or cardiac bypass may be instituted.[20] ECMO can worsen coagulopathy and thrombosis in cases where obstetric hemorrhage or disseminated intravascular coagulation is present.[18],[19],[41],[55] Health care teams should start post-resuscitation care, including early organ support strategies regardless of the patient's location and management strategies according to the cause of arrest.
Recommendations:
If the fetus has not been delivered, a MLUD should be maintained.Following ROSC, post resuscitation care should start along with surgical repair, hemostasis, antibiotics, and intensive care protocols.[16]ECMO CPR is recommended to stabilize the obstetric patients when cardiopulmonary causes have resulted in cardiac arrest. However, ECMO can activate coagulation factors and worsen thrombosis or coagulopathy; hence, caution should be exercised in such patients.Therapeutic hypothermia in the post arrest patient is recommended to decrease the impact of injury to the cardiac and neuronal tissue.[24],[56] However, in patients with maternal hemorrhage or coagulopathy, caution must be exercised as hypothermia may precipitate blood loss and worsen hemostasis.[57] Important ConsiderationsDocumentation
Precise truthful real-time documentation is critical in all cases of maternal collapse, whether or not resuscitation is successful. Potential clinical and medico legal consequences can pose problems for the professionals in case of a mishap. Thorough documentation of all steps of management after the event should be ensured.[58]
Incident reporting
It is important to have a nationwide reporting and audit of maternal deaths that has the potential to provide useful information, learning, and quality improvement. However, in most of the developing countries, a national registry is sorely lacking.[59]
Debriefing and training
Debriefing is strongly recommended for health care providers involved during the event.[60] All the health care providers in the obstetric units should undergo multidisciplinary training in cardiopulmonary resuscitation annually to improve their skills. Management of obstetric emergencies such as maternal collapse with special emphasis on adaptations for CPR in pregnancy should be part of the formal multidisciplinary training. Collaborative training has been shown to improve teamwork, communication, and the confidence of obstetric care providers thereby empowering them to manage obstetric emergencies, including quick performance of RUI.[61],[62],[63]
All team members and leaders should be familiar with the location, use of emergency drugs, and equipment. Local maternal resuscitation protocols should be developed and revised regularly. There should be a checklist of key tasks to be carried out at initiation of CPR following MCA.
When to terminate CPR?
The decision to cease CPR should be taken by the multidisciplinary team involving the primary care physicians and resuscitation team leader.
Ethical issues in MCA
Brain dead parturient[64] following ROSC requiring life support but with reassuring fetal heart trace are ethical enigmas. Decision to prolong the pregnancy until fetal viability, organ donation, etc., are complex decisions necessitating family counseling, honoring their decision, and consideration of local regulations. The health care organization should involve their ethics committee and local legal functionaries for medicolegal concerns.
ConclusionPerformance of a high-quality CPR in a pregnant patient imposes a high cognitive and emotional load on the health care provider. Timely recognition, activation of maternal emergency team, noting the time of arrest whilst adhering to the standard basic and advanced cardiac life support guidelines with special attention to maintaining MLUD, and initiating RUI at the site of cardiac arrest are advocated. Execution of these interventions seamlessly requires excellent teamwork specifically assigning clear responsibilities and repeated practice at workshops and in-hospital mock drills.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
References
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