Elsevier

Resuscitation

Volume 84, Issue 2, February 2013, Pages 200-205
Resuscitation

The prognostic value of continuous amplitude-integrated electroencephalogram applied immediately after return of spontaneous circulation in therapeutic hypothermia-treated cardiac arrest patients

https://doi.org/10.1016/j.resuscitation.2012.09.031Get rights and content

Abstract

Introduction

The purpose of this study was to examine the prognostic value of continuous amplitude-integrated electroencephalogram (aEEG) applied immediately after return of spontaneous circulation (ROSC) in therapeutic hypothermia (TH)-treated cardiac arrest patients.

Methods

From September 2010 to August 2011, we prospectively studied comatose patients treated with TH after cardiac arrest who were monitored with aEEG. Monitoring at the forehead was applied as soon as possible after ROSC in the emergency department and continued until recovery of consciousness, death, or 72 h after ROSC. Neurological outcome was assessed with the Cerebral Performance Category (CPC) scale at hospital discharge, and good neurological outcome was defined as a CPC score of 1 or 2.

Results

A total of 55 TH-treated patients were included. Monitoring started at a median of 96 min after ROSC (interquartile range, 49–174). At discharge, 28 patients had a CPC of 1–2, and 27 patients had a CPC of 3–5. Seventeen patients had a continuous normal voltage (CNV) trace at the start of monitoring, and this voltage was strongly associated with a good outcome (16/17 [94.1%]; sensitivity and specificity of 57.1 and 96.3%, respectively). No development of a CNV trace within the recorded period accurately predicted a poor outcome (21/21 [100%]; sensitivity and specificity of 77.8 and 100%, respectively).

Conclusions

An initial CNV trace in aEEG applied to forehead immediately after ROSC is a good early predictor of a good outcome in TH-treated cardiac arrest patients. Conversely, no development of a CNV trace within 72 h is an accurate and reliable predictor of a poor outcome with a false-positive rate of 0%.

Introduction

The International Liaison Committee on Resuscitation recommends that unconscious patients who present after having been resuscitated from out-of-hospital cardiac arrest (OHCA) be cooled to between 32 and 34 °C for 12–24 h.1, 2 Randomised clinical trials showed improved neurological outcome after therapeutic hypothermia (TH) for comatose survivors with out-of-hospital ventricular fibrillation.3, 4 However, despite these interventions, a significant number of these patients remain permanently unresponsive or suffer from severe cognitive impairment and long-term disability. Therefore, the early prognostication of neurological outcome in these patients is important in guiding post-cardiac arrest management strategies and is an essential component of post-cardiac arrest care.

Recently, many studies have reported that several electroencephalogram (EEG) features may significantly improve prognostication in these patients at an early phase,5, 6 and several prospective studies on the prognostic value of continuous EEG (cEEG) findings during TH in patients with postanoxic coma have been conducted.7, 8 However, cEEG monitoring requires experienced specialists for application and interpretation and is often unavailable. To perform a more prudent care of post-cardiac arrest patients, methods that allow non-neurologists and other physicians to apply TH to examine the response of brain activity need to be developed.9 Amplitude-integrated electroencephalograms (aEEGs) are generated from single- or two-channel EEG recordings, and the records they produce are notably easy to read. aEEG patterns predict neurological outcome in perinatal hypoxic-ischemic encephalopathy (HIE) in neonates,10, 11, 12, 13 and in adult, Rundgren et al. reported that patterns of aEEG applied in intensive care unit (ICU) correlate with outcome after cardiac arrest.14, 15

We performed a prospective study to evaluate the prognostic value of aEEG applied immediately after return of spontaneous circulation (ROSC) in the emergency department (ED) and continued for 72 h in TH-treated cardiac arrest patients.

Section snippets

Patients

We prospectively studied comatose survivors of cardiac arrest in the ED of Seoul St. Mary's Hospital, a 1200-bed tertiary care teaching hospital in Seoul, Korea. This study was conducted from September 2010 to August 2011. The study was approved by the Institutional Review Board of the Catholic University of Korea, Seoul Saint Mary's Hospital, and informed consent from each patient's next of kin was obtained.

All adult (age >19 years) patients who achieved ROSC after resuscitation from cardiac

Patients

During the time period of the study, a total of 99 cardiac arrest patients were continuously monitored with aEEG. Of these patients, 34 were not treated with TH. Of the remaining patients, ten were excluded from the study; 3 were not included because of data loss, and 7 were excluded because of death before 72 h. Finally, we studied 55 comatose cardiac arrest survivors treated with TH and monitored with aEEG until recovery of consciousness, death, or 72 h after ROSC (Fig. 3). Of these patients,

Discussion

This study has shown that many comatose patients had an initial CNV trace in aEEG applied to forehead immediately after ROSC and it was reliable to predict a good outcome in TH-treated patients. We also found that no development of a CNV trace within 3 days was an accurate and reliable predictor of poor outcome. The majority of patients resuscitated from cardiac arrest are comatose,16 and the treatment of shivering and ventilator care mainly require sedative or paralytic medication during

Conclusions

aEEG applied to forehead immediately after ROSC and continued until 72 h after cardiac arrest is sensitive in predicting both good and poor outcomes in TH-treated post-cardiac arrest patients. An initial CNV trace (median: 133 min after ROSC) is a good early predictor of good outcome in comatose TH-treated cardiac arrest patients. Conversely, failure to develop a CNV trace within 72 h is an accurate and reliable (false-positive rate of 0%) predictor of poor outcome.

Conflict of interest statement

The authors do not have any financial or other relationships that might pose any conflicts of interest.

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    A Spanish translated version of the summary of this article appears as Appendix in the final online version at http://dx.doi.org/10.1016/j.resuscitation.2012.09.031.

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