title: Neurologic outcome in comatose patients resuscitated from out-of-hospital cardiac arrest with prolonged downtime and treated with therapeutic hypothermia.
abstract: BACKGROUND
  Previous reports have shown that prolonged duration of resuscitation efforts in out-of-hospital cardiac arrest (OHCA) is associated with poor neurologic outcome. This concept has recently been questioned with advancements in post-cardiac arrest care including the use of therapeutic hypothermia (TH). The aim of this study was to determine the rate of good neurologic outcome based on the duration of resuscitation efforts in OHCA patients treated with TH.
  
  
  METHODS
  This prospective, observational, study was conducted between January 2008 and September 2012. Inclusion criteria consisted of adult non-traumatic OHCA patients who were comatose after return of spontaneous circulation (ROSC) and received TH. The primary endpoint was good neurologic outcome defined as a cerebral performance category score of 1 or 2. Downtime was calculated as the length of time between the patient being recognized as pulseless and ROSC.
  
  
  RESULTS
  105 patients were treated with TH and 19 were excluded due to unknown downtime, leaving 86 patients for analysis. The median downtime was 18.5 (10.0-32.3)min and 33 patients (38.0%) had a good neurologic outcome. When downtime was divided into four groups (≤10min, 11-20min, 21-30min, >30min), good neurologic outcomes were 62.5%, 37%, 25%, and 21.7%, respectively (p=0.02). However, even with downtime >20min, 22.9% had a good neurologic outcome, and this percentage increased to 37.5% in patients with an initial shockable rhythm.
  
  
  CONCLUSIONS
  Although longer downtime is associated with worse outcome in OHCA patients, we found that comatose patients who have been successfully resuscitated and treated with TH have neurologically intact survival rates of 23% even with downtime >20min.
authors.affiliation: Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, MA, United States; Department of Emergency Medicine, Ulsan University College of Medicine, Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Won Young
authors.initials: WY
authors.lastname: Kim
authors.affiliation: Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, MA, United States.
authors.forename: Tyler A
authors.initials: TA
authors.lastname: Giberson
authors.affiliation: Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, MA, United States.
authors.forename: Amy
authors.initials: A
authors.lastname: Uber
authors.affiliation: Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, MA, United States; Department of Medicine, Division of Pulmonary and Critical Care, Beth Israel Deaconess Medical Center, United States.
authors.forename: Katherine
authors.initials: K
authors.lastname: Berg
authors.affiliation: Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, MA, United States; Department of Anesthesia Critical Care, Division of Critical Care, Beth Israel Deaconess Medical Center, United States.
authors.forename: Michael N
authors.initials: MN
authors.lastname: Cocchi
authors.affiliation: Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, MA, United States; Department of Medicine, Division of Pulmonary and Critical Care, Beth Israel Deaconess Medical Center, United States. Electronic address: mdonnino@bidmc.harvard.edu.
authors.forename: Michael W
authors.initials: MW
authors.lastname: Donnino
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D003128:Coma / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007036:Hypothermia, Induced / Q000379:methods*; D015994:Incidence; D008297:Male; D008875:Middle Aged; D058687:Out-of-Hospital Cardiac Arrest / Q000150:complications / Q000401:mortality / Q000628:therapy*; D010865:Pilot Projects; D011446:Prospective Studies; D015996:Survival Rate / Q000639:trends; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology
keywords: Out-of-hospital cardiac arrest; Outcome; Therapeutic hypothermia
references.citation: Bull Johns Hopkins Hosp. 1960 Feb;106:74-80
references.pmid: 13804599
references.citation: Ann Emerg Med. 1983 Dec;12(12):733-8
references.pmid: 6650939
references.citation: N Engl J Med. 2002 Feb 21;346(8):557-63
references.pmid: 11856794
references.citation: Resuscitation. 2006 Oct;71(1):40-6
references.pmid: 16945468
references.citation: Crit Care Med. 1985 Oct;13(10):818-29
references.pmid: 3928249
references.citation: Stroke. 1995 Nov;26(11):2127-33; discussion 2133-4
references.pmid: 7482661
references.citation: Am J Emerg Med. 1985 Mar;3(2):114-9
references.pmid: 3970766
references.citation: CJEM. 2006 Sep;8(5):329-37
references.pmid: 17338844
references.citation: Crit Care Med. 2005 Feb;33(2):414-8
references.pmid: 15699847
references.citation: Resuscitation. 1998 Jan;36(1):45-9
references.pmid: 9547843
references.citation: Lancet. 2012 Oct 27;380(9852):1473-81
references.pmid: 22958912
references.citation: Crit Care Med. 2007 Apr;35(4):1041-7
references.pmid: 17334257
references.citation: Lancet. 1975 Mar 1;1(7905):480-4
references.pmid: 46957
references.citation: Resuscitation. 2012 Oct;83(10):1253-8
references.pmid: 22388092
references.citation: N Engl J Med. 2002 Feb 21;346(8):549-56
references.pmid: 11856793
references.citation: Circulation. 2013 Jan 29;127(4):442-51
references.pmid: 23339874
references.citation: Acta Anaesthesiol Scand. 2007 Aug;51(7):866-71
references.pmid: 17635393
references.citation: Resuscitation. 2010 Oct;81(10):1305-52
references.pmid: 20956049
references.citation: Ann Emerg Med. 1987 Feb;16(2):142-6
references.pmid: 3800085
references.citation: Resuscitation. 1996 Nov;33(1):13-7
references.pmid: 8959768
references.citation: Circulation. 2010 Nov 2;122(18 Suppl 3):S768-86
references.pmid: 20956225
references.citation: Curr Opin Crit Care. 2006 Jun;12(3):213-7
references.pmid: 16672779
references.citation: J Am Coll Cardiol. 2002 Dec 18;40(12):2110-6
references.pmid: 12505221