Faculty Bibliography

BACKGROUND: Despite numerous advances in the delivery of resuscitative care, in-hospital cardiac arrest (IHCA) continues to be associated with high morbidity and mortality. We sought to study the impact of arterial oxygen tension (Pao 2) on return of spontaneous circulation (ROSC) and survival to discharge in patients with IHCA. METHODS: The study population included 255 consecutive patients who underwent advanced cardiac life support-guided resuscitation from January 2012 to December 2013 for IHCA at an academic tertiary medical center. Of these patients, 167 underwent arterial blood gas testing at the time of the arrest. Baseline demographic, clinical, laboratory, and clinical outcome data were recorded. The primary outcome of interest was survival to hospital discharge. Secondary outcome of interest was presence of ROSC. RESULTS: Of the 167 patients studied, Pao 2 categorization included the following: Pao 2 < 60 mm Hg (n = 38), Pao 2 of 60-92 mm Hg (n = 44), Pao 2 of 93 to 159 mm Hg (n = 43), Pao 2 of 160 to 299 mm Hg (n = 24), and Pao 2 >/= 300 mm Hg (n = 18). Patients with higher Pao 2 levels during the time of cardiac arrest were noted to have higher rates of hypertension and chronic kidney disease. Clinical presentation of IHCA, in particular, the initial rhythm, location of IHCA, and duration of cardiopulmonary resuscitation, was similar in all groups. Patients with higher Pao 2 levels had higher platelet count, higher arterial pH, and lower arterial carbon dioxide tension (Pco 2). With respect to outcomes, patients with higher intra-arrest Pao 2 levels had progressively higher rates of ROSC (58% vs 71% vs 72% vs 79% vs 100%, P = .021) and survival to discharge (16% vs 23% vs 30% vs 33% vs 56%, P = .031). In multivariate analysis, Pao 2 >/= 300 mm Hg was independently associated with higher survival to discharge (odds ratio 60.68; 95% confidence interval: 3.04-1210.28; P = .007; referent Pao 2 < 60 mm Hg). CONCLUSION: Higher intra-arrest Pao 2 is independently associated with higher rates of survival to discharge in adults with IHCA.

OBJECTIVES/OBJECTIVE:To date, no studies have examined real-time electroencephalography and cerebral oximetry monitoring during cardiopulmonary resuscitation as markers of the magnitude of global ischemia. We therefore sought to assess the feasibility of combining cerebral oximetry and electroencephalography in patients undergoing cardiopulmonary resuscitation and further to evaluate the electroencephalography patterns during cardiopulmonary resuscitation and their relationship with cerebral oxygenation as measured by cerebral oximetry. DESIGN/METHODS:Extended case series of in-hospital and out-of-hospital cardiac arrest subjects. SETTING/METHODS:Tertiary Medical Center. PATIENTS/METHODS:Inclusion criteria: Convenience sample of 16 patients undergoing cardiopulmonary resuscitation during working hours between March 2014 and March 2015, greater than or equal to 18 years. A portable electroencephalography (Legacy; SedLine, Masimo, Irvine, CA) and cerebral oximetry (Equanox 7600; Nonin Medical, Plymouth, MN) system was used to measure cerebral resuscitation quality. INTERVENTIONS/METHODS:Real-time regional cerebral oxygen saturation and electroencephalography readings were observed during cardiopulmonary resuscitation. The regional cerebral oxygen saturation values and electroencephalography patterns were not used to manage patients by clinical staff. MEASUREMENTS AND MAIN RESULTS/RESULTS:In total, 428 electroencephalography images from 16 subjects were gathered; 40.7% (n = 174/428) were artifactual, therefore 59.3% (n = 254/428) were interpretable. All 16 subjects had interpretable images. Interpretable versus noninterpretable images were not related to a function of time or duration of cardiopulmonary resuscitation but to artifacts that were introduced to the raw data such as diaphoresis, muscle movement, or electrical interference. Interpretable data were able to be obtained immediately after application of the electrode strip. Seven distinct electroencephalography patterns were identified. Voltage suppression was commonest and seen during 78% of overall cardiopulmonary resuscitation time and in 15 of 16 subjects at some point during their cardiopulmonary resuscitation. Other observed patterns and their relative prevalence in relation to overall cardiopulmonary resuscitation time were theta background activity 8%, delta background activity 5%, bi frontotemporal periodic discharge 4%, burst suppression 2%, spike and wave 2%, and rhythmic delta activity 1%. Eight of 16 subjects had greater than one interpretable pattern. At regional cerebral oxygen saturation levels less than or equal to 19%, the observed electroencephalography pattern was exclusively voltage suppression. Delta background activity was only observed at regional cerebral oxygen saturation levels greater than 40%. The remaining patterns were observed throughout regional cerebral oxygen saturation categories above a threshold of 20%. CONCLUSIONS:Real-time monitoring of cerebral oxygenation and function during cardiac arrest resuscitation is feasible. Although voltage suppression is the commonest electroencephalography pattern, other distinct patterns exist that may correlate with the quality of cerebral resuscitation and oxygen delivery.

STUDY OBJECTIVE/OBJECTIVE:at predicting ROSC in ED patients with out-of-hospital cardiac arrest (OHCA). METHODS:predicted ROSC. RESULTS:was more specific (85%, 95% CI, 74-92 vs. 45%, 33-57). CONCLUSIONS:is more specific at predicting ROSC in OHCA.

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.