Clinical paperTime to awakening and neurologic outcome in therapeutic hypothermia-treated cardiac arrest patients☆,☆☆
Introduction
Sudden cardiac arrest (SCA) affects approximately 300,000 people annually in the U.S. with a survival rate of <10% at hospital discharge [1] and significant long-term neurologic deficits in up to 50% of survivors [2], [3]. Both SCA patients who suffer such deficits and those who regain meaningful neurologic function generally remain comatose for days post-arrest, often secondary to anoxic encephalopathy and complicated by pharmacologic interventions. Consequently, a consensus statement put forth by the American Academy of Neurology (AAN) in 2006 addressing the value of prognostic indicators in SCA patients, recommends delaying neuroprognostication for at least 72 h post-arrest [2]. Recent innovations have altered the approach to post-arrest care, particularly the use of therapeutic hypothermia (TH) [4], [5], [6], [7], [8], [9], requiring reassessment of the applicability of the AAN recommendation [10], [11], [12], [13], [14].
In this investigation, our primary outcome was time to awakening in comatose post-cardiac arrest syndrome (PCAS) patients treated with TH. The secondary outcome examined neurologic function at discharge, described by Cerebral Performance Category (CPC) score. Several clinical factors were identified that might influence time to awakening, including medications administered, comorbid conditions, and seizure. We hypothesized that patients who survive with good neurologic function will have a shorter time to awakening than those who survive with poor neurologic function. Further, we sought to investigate whether patient-level factors (age, sex, race, renal sufficiency) or arrest-level factors (initial rhythm, location of arrest) were associated with time to awakening.
Section snippets
Methods
We utilized SCA data from the Penn Alliance for Therapeutic Hypothermia (PATH) database, an internet-based registry hosted at the University of Pennsylvania. The PATH database includes SCA data in the pre-hospital, emergency department, and in-hospital settings, focusing on post-arrest care, particularly TH. Open to any U.S. institution, it tracks all patients who experience SCA and receive cardiopulmonary resuscitation. This investigation received approval from the University of Pennsylvania
Results
During the study period, 201 consecutive PCAS patients were treated with TH via a standardized post-arrest protocol. Seven patients were excluded because of a primary neurologic arrest etiology, leaving a final cohort of 194. The mean age was 57 ± 16 years; 114/194 (59%) were male; 76/190 (40%) had VF/VT as an initial arrest rhythm. Forty-four percent (85/194) survived to hospital discharge, with 78% (66/85) of these patients discharged with CPC 1–2 (Table 1). Of the 44% (85/194) who awakened,
Discussion
In a cohort of 194 comatose TH-treated PCAS patients, shorter time to awakening was significantly associated with better neurologic outcome. Time to awakening was not associated with age, sex, race, initial rhythm, ESRD, paralytic use, seizure, or location of arrest.
Our results are consistent with a prior small single-center investigation of post-arrest patients treated with TH. In a cohort of 47 out-of-hospital arrests, Eid et al. found that meaningful awakening, defined as CPC 1–2, could
Conflict of interest statement
Ms. Leary has served as a consultant for Stryker Corporation. Dr. Abella receives research support from NHLBI, Phillips Healthcare, Medtronic Inc., and the Doris Duke Foundation, has received honoraria from Medivance Corporation, and serves as a consultant to Velomedix Inc. and serves on the medical advisory board for HeartSine Technologies Inc. Dr. Gaieski has received research support, receives honoraria, and has served as a consultant for Stryker Corporation.
References (29)
- et al.
Reply to letter: more evidence is required before we alter guidance on prognostication following cardiac arrest
Resuscitation
(2011) - et al.
The frequency and timing of epileptiform activity on continuous electroencephalogram in comatose post-cardiac arrest syndrome patients treated with therapeutic hypothermia
Resuscitation
(2012) - et al.
Association between a quantitative CT scan measure of brain edema and outcome after cardiac arrest
Resuscitation
(2011) - et al.
Association between clinical examination and outcome after cardiac arrest
Resuscitation
(2010) - et al.
Neurologic prognostication and bispectral index monitoring after resuscitation from cardiac arrest
Resuscitation
(2010) - et al.
Heart disease and stroke statistics – 2010 update: a report from the American Heart Association
Circulation
(2010) - et al.
Practice parameter prediction of outcome in comatose survivors after cardiopulmonary resuscitation (an evidence-based review) – report of the quality standards subcommittee of the American Academy of Neurology
Neurology
(2006) - et al.
Cardiac arrest resuscitation: neurologic prognostication and brain death
Curr Opin Crit Care
(2008) - et al.
Treatment of comatose survivors of out-of-hospital cardiac arrest with induced hypothermia
N Engl J Med
(2002) - et al.
Mild therapeutic hypothermia to improve the neurologic outcome after cardiac arrest
N Engl J Med
(2002)
Part 5: adult basic life support: 2010. American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care
Circulation
Clinical application of mild therapeutic hypothermia after cardiac arrest
Crit Care Med
Outcome, timing and adverse events in therapeutic hypothermia after out-of-hospital cardiac arrest
Acta Anaesthesiol Scand
Therapeutic hypothermia after cardiac arrest in clinical practice: review and compilation of recent experiences
Crit Care Med
Cited by (85)
Initial arterial pH as a predictor of neurologic outcome after out-of-hospital cardiac arrest: A propensity-adjusted analysis
2019, ResuscitationCitation Excerpt :TTM is recommended for 24 h at 32–36 °C regardless of arrest rhythm,3 a guideline supported by randomized control trial4–6 and meta-analysis7–9 data. In TTM-treated OHCA patients, current recommendations are to delay neurologic prognostication >72 h post-arrest,3,10 a timeline consistent with reported average awakening 3.2 days post-OHCA.11 Nevertheless, the majority of patients will not recover meaningful neurologic function.
- ☆
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.2013.07.009.
- ☆☆
This manuscript was supported by unrestricted funding for the Penn Alliance for Therapeutic Hypothermia (PATH) database, provided by Stryker Industries.