title: The Utility of Therapeutic Hypothermia for Post-Cardiac Arrest Syndrome Patients With an Initial Nonshockable Rhythm.
abstract: BACKGROUND
  Therapeutic hypothermia (TH) attenuates reperfusion injury in comatose survivors of cardiac arrest. The utility of TH in patients with nonshockable initial rhythms has not been widely accepted. We sought to determine whether TH improved neurological outcome and survival in postarrest patients with nonshockable rhythms.
  
  
  RESULTS
  We identified 519 patients after in- and out-of-hospital cardiac arrest with nonshockable initial rhythms from the Penn Alliance for Therapeutic Hypothermia (PATH) registry between 2000 and 2013. Propensity score matching was used. Patient and arrest characteristics used to estimate the propensity to receive TH were age, sex, location of arrest, witnessed arrest, and duration of arrest. To determine the association between TH and outcomes, we created 2 multivariable logistic models controlling for confounders. Of 201 propensity score-matched pairs, mean age was 63 ± 17 years, 51% were male, and 60% had an initial rhythm of pulseless electric activity. Survival to hospital discharge was greater in patients who received TH (17.6% versus 28.9%; P < 0.01), as was a discharge Cerebral Performance Category of 1 to 2 (13.7% versus 21.4%; P = 0.04). In adjusted analyses, patients who received TH were more likely to survive (odds ratio, 2.8; 95% confidence interval, 1.6-4.7) and to have better neurological outcome (odds ratio, 3.5; 95% confidence interval, 1.8-6.6) than those that did not receive TH.
  
  
  CONCLUSIONS
  Using propensity score matching, we found that patients with nonshockable initial rhythms treated with TH had better survival and neurological outcome at hospital discharge than those who did not receive TH. Our findings further support the use of TH in patients with initial nonshockable arrest rhythms.
authors.affiliation: From the University of Colorado School of Medicine, Department of Emergency Medicine, Aurora (S.M.P.); University of Pennsylvania, Perelman School of Medicine, Department of Biostatistics and Epidemiology, Philadelphia (A.V.G., D.J.W.); University of Pennsylvania, Center for Resuscitation Science, Philadelphia (A.V.G., B.S.A.); University of Pennsylvania, Perelman School of Medicine, Department of Emergency Medicine, Philadelphia (A.V.G., D.J.W., B.S.A.); and Thomas Jefferson University, Sidney Kimmel School of Medicine, Department of Emergency Medicine, Philadelphia, PA (B.G.C., D.F.G.). sarah.perman@ucdenver.edu.
authors.forename: Sarah M
authors.initials: SM
authors.lastname: Perman
authors.affiliation: From the University of Colorado School of Medicine, Department of Emergency Medicine, Aurora (S.M.P.); University of Pennsylvania, Perelman School of Medicine, Department of Biostatistics and Epidemiology, Philadelphia (A.V.G., D.J.W.); University of Pennsylvania, Center for Resuscitation Science, Philadelphia (A.V.G., B.S.A.); University of Pennsylvania, Perelman School of Medicine, Department of Emergency Medicine, Philadelphia (A.V.G., D.J.W., B.S.A.); and Thomas Jefferson University, Sidney Kimmel School of Medicine, Department of Emergency Medicine, Philadelphia, PA (B.G.C., D.F.G.).
authors.forename: Anne V
authors.initials: AV
authors.lastname: Grossestreuer
authors.affiliation: From the University of Colorado School of Medicine, Department of Emergency Medicine, Aurora (S.M.P.); University of Pennsylvania, Perelman School of Medicine, Department of Biostatistics and Epidemiology, Philadelphia (A.V.G., D.J.W.); University of Pennsylvania, Center for Resuscitation Science, Philadelphia (A.V.G., B.S.A.); University of Pennsylvania, Perelman School of Medicine, Department of Emergency Medicine, Philadelphia (A.V.G., D.J.W., B.S.A.); and Thomas Jefferson University, Sidney Kimmel School of Medicine, Department of Emergency Medicine, Philadelphia, PA (B.G.C., D.F.G.).
authors.forename: Douglas J
authors.initials: DJ
authors.lastname: Wiebe
authors.affiliation: From the University of Colorado School of Medicine, Department of Emergency Medicine, Aurora (S.M.P.); University of Pennsylvania, Perelman School of Medicine, Department of Biostatistics and Epidemiology, Philadelphia (A.V.G., D.J.W.); University of Pennsylvania, Center for Resuscitation Science, Philadelphia (A.V.G., B.S.A.); University of Pennsylvania, Perelman School of Medicine, Department of Emergency Medicine, Philadelphia (A.V.G., D.J.W., B.S.A.); and Thomas Jefferson University, Sidney Kimmel School of Medicine, Department of Emergency Medicine, Philadelphia, PA (B.G.C., D.F.G.).
authors.forename: Brendan G
authors.initials: BG
authors.lastname: Carr
authors.affiliation: From the University of Colorado School of Medicine, Department of Emergency Medicine, Aurora (S.M.P.); University of Pennsylvania, Perelman School of Medicine, Department of Biostatistics and Epidemiology, Philadelphia (A.V.G., D.J.W.); University of Pennsylvania, Center for Resuscitation Science, Philadelphia (A.V.G., B.S.A.); University of Pennsylvania, Perelman School of Medicine, Department of Emergency Medicine, Philadelphia (A.V.G., D.J.W., B.S.A.); and Thomas Jefferson University, Sidney Kimmel School of Medicine, Department of Emergency Medicine, Philadelphia, PA (B.G.C., D.F.G.).
authors.forename: Benjamin S
authors.initials: BS
authors.lastname: Abella
authors.affiliation: From the University of Colorado School of Medicine, Department of Emergency Medicine, Aurora (S.M.P.); University of Pennsylvania, Perelman School of Medicine, Department of Biostatistics and Epidemiology, Philadelphia (A.V.G., D.J.W.); University of Pennsylvania, Center for Resuscitation Science, Philadelphia (A.V.G., B.S.A.); University of Pennsylvania, Perelman School of Medicine, Department of Emergency Medicine, Philadelphia (A.V.G., D.J.W., B.S.A.); and Thomas Jefferson University, Sidney Kimmel School of Medicine, Department of Emergency Medicine, Philadelphia, PA (B.G.C., D.F.G.).
authors.forename: David F
authors.initials: DF
authors.lastname: Gaieski
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016887:Cardiopulmonary Resuscitation / Q000009:adverse effects* / Q000639:trends; D015331:Cohort Studies; D005260:Female; D006323:Heart Arrest / Q000401:mortality* / Q000628:therapy*; D006801:Humans; D007036:Hypothermia, Induced / Q000401:mortality* / Q000706:statistics & numerical data* / Q000639:trends; D008297:Male; D008875:Middle Aged; D058687:Out-of-Hospital Cardiac Arrest / Q000401:mortality / Q000628:therapy; D012189:Retrospective Studies; D013577:Syndrome; D016896:Treatment Outcome
keywords: cardiopulmonary resuscitation; heart arrest; hypothermia, induced; resuscitation