Faculty Bibliography

PURPOSE OF REVIEW: Of the approximately 350,000 out-of-hospital, and 750,000 after in-hospital cardiac arrest (CA) events in the US annually approximately 5-9% and 20% respectively may achieve return of spontaneous circulation (ROSC) after attempted cardiopulmonary resuscitation (CPR). Up to 2/3 of these initial survivors may go on die in the subsequent 24-72 hours after ROSC due to a combination of (1) on-going cerebral injury, (2) myocardial dysfunction and (3) massive systemic inflammatory response. In order to successfully manage patients more effectively, monitoring methods are needed to aid clinicians in the detection and quantification of intra-cardiac arrest and post-resuscitation pathophysiological cerebral injury processes in the intensive care unit. RECENT FINDINGS: Over the last few years many modalities have been used for cerebral monitoring during and after CA, these include quantitative pupillometry, transcranial doppler sonography, optic nerve sheath diameter measurements, microdialysis, tissue oxygenation monitoring, intra-cranial pressure monitoring, and electroencephalography. Current studies indicate that these modalities may be used for the purpose of neurological monitoring during cardiac arrest resuscitation as well as in the post-resuscitation period. Multiple overlapping processes, including alterations in cerebral blood flow (CBF), raised intracerebralpressure, disorders of metabolism, imbalanced oxygen delivery and reperfusion injury contribute to cell death during the post-resuscitation period has led to the birth of post-resuscitation management strategies in the 21st century. This review provides a succinct overview of currently available bedside invasive and non-invasive neuro-monitoring methods after CA.

BACKGROUND: Epinephrine has been presumed to improve cerebral oxygen delivery during cardiopulmonary resuscitation (CPR), but animal and registry studies suggest that epinephrine-induced capillary vasoconstriction may decrease cerebral capillary blood flow and worsen neurological outcome. The effect of epinephrine on cerebral oxygenation (rSO2) during CPR has not been documented in the clinical setting. METHODS: rSO2 was measured continuously using cerebral oximetry in patients with in-hospital cardiac arrest. During CPR, time event markers recorded the administration of 1mg epinephrine. rSO2 values were analysed for a period beginning 5min before and ending 5min after the first epinephrine administration. RESULTS: A total of 56 epinephrine doses were analysed in 36 patients during CPR. The average rSO2 value in the 5-min following epinephrine administration was 1.40% higher (95% CI=0.41-2.40%; P=0.0059) than in the 5-min period before epinephrine administration. However, there was no difference in the overall rate of change of rSO2 when comparing the 5-min period before, with the 5-min period immediately after a single bolus dose of epinephrine (0.88%/min vs 1.07%/min respectively; P=0.583), There was also no difference in the changes in rSO2 at individual 1, 2, 3, or 4-min time windows before and after a bolus dose of epinephrine (P=0.5827, 0.2371, 0.2082, and 0.6707 respectively). CONCLUSIONS: A bolus of 1mg epinephrine IV during CPR produced a small but clinically insignificant increase in rSO2 in the five minutes after administration. This is the first clinical data to demonstrate the effects of epinephrine on cerebral rSO2 during CPR.

OBJECTIVES: Cardiac arrest is associated with morbidity and mortality because of cerebral ischemia. Therefore, we tested the hypothesis that higher regional cerebral oxygenation during resuscitation is associated with improved return of spontaneous circulation, survival, and neurologic outcomes at hospital discharge. We further examined the validity of regional cerebral oxygenation as a test to predict these outcomes. DESIGN: Multicenter prospective study of in-hospital cardiac arrest. SETTING: Five medical centers in the United States and the United Kingdom. PATIENTS: Inclusion criteria are as follows: in-hospital cardiac arrest, age 18 years old or older, and prolonged cardiopulmonary resuscitation greater than or equal to 5 minutes. Patients were recruited consecutively during working hours between August 2011 and September 2014. Survival with a favorable neurologic outcome was defined as a cerebral performance category 1-2. INTERVENTIONS: Cerebral oximetry monitoring. MEASUREMENTS AND MAIN RESULTS: Among 504 in-hospital cardiac arrest events, 183 (36%) met inclusion criteria. Overall, 62 of 183 (33.9%) achieved return of spontaneous circulation, whereas 13 of 183 (7.1%) achieved cerebral performance category 1-2 at discharge. Higher mean +/- SD regional cerebral oxygenation was associated with return of spontaneous circulation versus no return of spontaneous circulation (51.8% +/- 11.2% vs 40.9% +/- 12.3%) and cerebral performance category 1-2 versus cerebral performance category 3-5 (56.1% +/- 10.0% vs 43.8% +/- 12.8%) (both p < 0.001). Mean regional cerebral oxygenation during the last 5 minutes of cardiopulmonary resuscitation best predicted the return of spontaneous circulation (area under the curve, 0.76; 95% CI, 0.69-0.83); regional cerebral oxygenation greater than or equal to 25% provided 100% sensitivity (95% CI, 94-100) and 100% negative predictive value (95% CI, 79-100); regional cerebral oxygenation greater than or equal to 65% provided 99% specificity (95% CI, 95-100) and 93% positive predictive value (95% CI, 66-100) for return of spontaneous circulation. Time with regional cerebral oxygenation greater than 50% during cardiopulmonary resuscitation best predicted cerebral performance category 1-2 (area under the curve, 0.79; 95% CI, 0.70-0.88). Specifically, greater than or equal to 60% cardiopulmonary resuscitation time with regional cerebral oxygenation greater than 50% provided 77% sensitivity (95% CI,:46-95), 72% specificity (95% CI, 65-79), and 98% negative predictive value (95% CI, 93-100) for cerebral performance category 1-2. CONCLUSIONS: Cerebral oximetry allows real-time, noninvasive cerebral oxygenation monitoring during cardiopulmonary resuscitation. Higher cerebral oxygenation during cardiopulmonary resuscitation is associated with return of spontaneous circulation and neurologically favorable survival to hospital discharge. Achieving higher regional cerebral oxygenation during resuscitation may optimize the chances of cardiac arrest favorable outcomes.

Cardiac arrest (CA) is a major cause of morbidity and mortality worldwide. Despite the use of conventional cardiopulmonary resuscitation (CPR), rates of return of spontaneous circulation and survival with minimal neurologic impairment remain low. Utilization of venoarterial extracorporeal membrane oxygenation (ECMO) for CA in adults is steadily increasing. Propensity-matched cohort studies have reported outcomes associated with ECMO use to be superior to that of conventional CPR alone in in-hospital patients with CA. In this review, we discuss the mechanism, indications, complications, and evidence for ECMO in CA in adults.

PURPOSE OF REVIEW: To provide a summary of the recent literature on clinical outcomes in adults with cardiac arrest, focusing on the impact of patient-specific factors in combination with cardio-pulmonary resuscitation (CPR) related, and postresuscitative-related factors. RECENT FINDINGS: Cardiac arrest is a major cause of morbidity and mortality worldwide. Despite the use of conventional cardiopulmonary resuscitation, rates of return of spontaneous circulation and survival with minimal neurologic impairment remain low. A number of recent studies have examined the impact of patient-specific factors (duration of cardiac arrest, initial rhythm, age, premorbid states), CPR-related (the use of mechanical CPR, the use of impedance threshold device, vasopressors, extra-corporeal membrane oxygenation, active compression-decompression, and impedance threshold device), and postresuscitative-related factors (hypothermia, coronary angiography, hyperoxia, hyper/hypocapnia, mean arterial blood pressure) on cardiac arrest outcomes. SUMMARY: Further studies, namely randomized controlled trials, assessing the impact of advanced therapies are warranted to evaluate their impact on survival and neurologic function in adults with cardiac arrest.