Cardiac Arrest in the Operating Room: Resuscitation and Management for the Anesthesiologist: Part 1

Vivek K. Moitra, MD; Sharon Einav, MD; Karl-Christian Thies, MD; Mark E. Nunnally, MD; Andrea Gabrielli, MD; Gerald A. Maccioli, MD; Guy Weinberg, MD; Arna Banerjee, MD; Kurt Ruetzler, MD; Gregory Dobson, MD; Matthew D. McEvoy, MD; Michael F. O'Connor, MD, FCCM


Anesth Analg. 2018;126(3):876-888. 

In This Article

Rescue Sequence for Cardiac Arrest in the Operating Room

Recognizing cardiac arrest in the operating room can be more difficult than it appears to nonoperating personnel. The vast majority of alarms from sensors such as the ECG and pulse oximeter are false alarms.[75,76] Bradycardia happens relatively frequently in patients undergoing anesthesia and is often associated with hypotension from the combination of anesthesia and little or no procedural stimulation. Patients with heart rates as low as 40 beats minute−1 can be clinically stable and do not require intervention as long as their blood pressure remains acceptable.[3] Finally, the combination of body habitus and pathology can render routine monitors useless. It can be difficult or impossible to obtain a reliable pulse oximetry tracing in hypothermic, hypovolemic, or vasculopathic patients.[77] Major burns or anasarca can frustrate noninvasive blood pressure, ECG, and pulse oximetry monitoring.

Features of cardiac arrest in the perioperative setting include an ECG with pulseless rhythms (ie, ventricular tachycardia, ventricular fibrillation, severe bradycardia, and asystole), loss of carotid pulse >10 seconds, loss of end-tidal CO2 (EtCO2) with loss of plethysmograph, and/or loss of an arterial line tracing. Of these, loss of EtCO2 is perhaps the most reliable and routinely monitored indicator of circulatory crisis or cardiac arrest.

Evaluation of EtCO2 should be in the context of the patient's clinical status. When minute ventilation is fixed and cardiac output is low, pulmonary blood flow determines EtCO2. Although low EtCO2 values are observed in low-flow states, conditions such as air leaks with supraglottic airways, increased airway resistance (mucous plugging, bronchospasm, endotracheal tube kinking), pulmonary edema, and hyperventilation also reduce EtCO2.[3] Hypermetabolic states such as malignant hyperthermia or neuroleptic malignant syndrome may also increase CO2 levels. The administration of intravenous sodium bicarbonate increases EtCO2 levels.

Once cardiac arrest is confirmed, CPR should be initiated without delay (Figure 4). Effective chest compression generates an EtCO2 close to or above 20 mm Hg, and higher EtCO2 values during CPR are associated with improved survival.[78] With few or no exceptions, EtCO2 <10 mm Hg after 20 minutes of standard ACLS is associated with failure of ROSC.[79–82] Several studies document that a relaxation (diastolic) pressure (calculated at the time of full chest decompression) of 30–40 mm Hg on an arterial tracing is associated with a higher rate of ROSC, even after prolonged CPR.[83–85] Modern defibrillators can provide real-time feedback on the quality of chest compressions, which can in turn drive timely rotation of rescuers performing CPR, and may lead to better outcomes.[86]

Figure 4.

Comprehensive algorithm. Adaptation of the ACLS comprehensive algorithm. Rescuers are prompted to evaluate or empirically treat early for hyperkalemia. Echocardiography is especially useful in establishing the most likely cause of pulseless electrical activity and focusing resuscitation efforts. ACLS indicates advanced cardiac life support; ASAP, as soon as possible; BP, blood pressure; CPR, cardiopulmonary resuscitation; ECG, electrocardiogram; ECMO, extracorporeal membrane oxygenation; Epi, epinephrine; Etco2, end-tidal carbon dioxide; IV, intravenous; PEA, pulseless electrical activity; PEEP, positive end-expiratory pressure; PTCA, percutaneous transluminal coronary angioplasty; ROSC, return of spontaneous circulation; Vaso, vasopressin; VF, ventricular fibrillation; VT, tidal volume.

Table shows a stepwise approach to the evaluation and management of cardiac arrest in the OR and perioperative setting. It is based on the 2010 and 2015 American Heart Association ACLS sequence and the International Liaison Committee on Resuscitation consensus statement on postcardiac arrest syndrome. Prolonged resuscitation efforts (up to 45 minutes) in inpatients have been associated with improved survivorship.[15]