Clinical paperAwakening after cardiac arrest and post resuscitation hypothermia: Are we pulling the plug too early?☆
Introduction
Over the past decade there have been major advances in post-resuscitation care following successful resuscitation from out-of-hospital cardiac arrest (OHCA). Use of therapeutic hypothermia (TH) in patients who present in a comatose state to the hospital has positively impacted the number of patients who survive with a favorable neurologic outcome.1, 2 However, little is known about the effect of TH on predicting who will ultimately regain consciousness and the time course to awakening. Further, the practice parameters for outcome prediction promulgated by the American Academy of Neurology (AAN) in 2006 pre-date the broad adoption of TH.3, 4
Recent retrospective and prospective studies indicate that TH and sedation influence neurologic examination and biochemical markers of recovery.5, 6 In the absence of reliable serum and clinical indicators we retrospectively analyzed time to awakening in all of our cardiac arrest survivors between 2006 and 2010. We sought to identify some distinguishing features of those who awoke >72 h following cardiac arrest (“late awakeners”).
Section snippets
Methods
St. Cloud Hospital (St. Cloud, MN, USA) is a community-based hospital that serves a population of ∼500,000 people in central Minnesota, USA. Since January 2006, it has been the clinical policy to treat all resuscitated OHCA patients with TH for 24 h if they were comatose upon intensive care unit admission or were unable to respond intelligibly.7 TH was administered as part of a protocol by Intensive Care Unit physicians and nurses that included ventilator support, sedation, paralysis to prevent
Statistical analysis
Due to the non-Gaussian distribution, data are reported as medians, interquartile range [IQR] and absolute range (range). Comparisons between groups were performed by the χ2 test or Fisher's exact test for categorical variables and by the Mann–Whitney U test or Kruskal–Wallis test to compare continuous variables within groups. To investigate correlation between continuous variables, Spearman's rho correlation test was performed. All analyses were 2 sided, and p values <0.05 were considered
Results
Between January 1, 2006 and December 21, 2010, 442 patients were moved to St. Cloud hospital after sustaining cardiac arrest (Fig. 1). A total of 257 patients were excluded as they died prior to hospital discharge whereas 185 patients were discharged alive. Of the 185 survivors, 96 patients were sufficiently awake upon arrival to the intensive care unit so they did not meet the TH protocol inclusion criteria. A total of 89 patients were treated with TH as they were comatose or could only
Discussion
Little is known about how long to pursue aggressive medical management in OHCA patients treated with TH once rewarming is completed. Neurological physical examinations are challenging when these patients remain persistently unresponsive, especially after a prolonged period of sedation. Neurological examinations have not been reported to be predictive of who will ultimately regain consciousness.3, 8, 9, 10, 11 There are many proposed markers of poor prognosis; the absence of the pupillary light
Conflict of interest statement
No conflicts of interest to declare.
References (16)
Unexpected good recovery in a comatose post-cardiac arrest patient with poor prognostic features
Resuscitation
(2013)- et al.
NSE and S-100B are not sufficiently predictive of neurologic outcome after therapeutic hypothermia for cardiac arrest
Resuscitation
(2013) - et al.
Post-hypoxic myoclonic status: the prognosis is not always hopeless
Crit Care Resusc
(2009) - et al.
Association between a quantitative CT scan measure of brain edema and outcome after cardiac arrest
Resuscitation
(2011) - et al.
Good neurological recovery of a post-cardiac arrest patient with very low bispectral index values and high suppression ratios after resumption of spontaneous circulation
Resuscitation
(2012) - et al.
Part 9: post-cardiac arrest care: 2010 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care
Circulation
(2010) Therapeutic hypothermia after cardiac arrest
Circulation
(2013)- 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)
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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.2013.10.030.