title: Vasopressin for cardiac arrest: meta-analysis of randomized controlled trials.
abstract: BACKGROUND
  Prior meta-analyses-reported results of randomised controlled trials (RCTs) published between 1997 and 2004 failed to show any vasopressin-related benefit in cardiac arrest. Based on new RCT-data and a hypothesis of a potentially increased vasoconstricting efficacy of vasopressin, we sought to determine whether the cumulative, current evidence supports or refutes an overall and/or selective benefit for vasopressin regarding sustained restoration of spontaneous circulation (ROSC), long-term survival, and neurological outcome.
  
  
  METHODS
  Two reviewers independently searched PubMed, EMBASE, and Cochrane Database for RCTs assigning adults with cardiac arrest to treatment with a vasopressin-containing regimen (vasopressin-group) vs adrenaline (epinephrine) alone (control-group) and reporting on long-term outcomes. Data from 4475 patients in 6 high-methodological quality RCTs were analyzed. Subgroup analyses were conducted according to initial cardiac rhythm and time from collapse to drug administration (T(DRUG))<20 min.
  
  
  RESULTS
  Vasopressin vs. control did not improve overall rates of sustained ROSC, long-term survival, or favourable neurological outcome. However, in asystole, vasopressin vs. control was associated with higher long-term survival {odds ratio (OR)=1.80, 95% confidence interval (CI)=1.04-3.12, P=0.04}. In asystolic patients of RCTs with average T(DRUG)<20 min, vasopressin vs. control increased the rates of sustained ROSC (data available from 2 RCTs; OR=1.70, 95% CI=1.17-2.47, P=0.005) and long-term survival (data available from 3 RCTs; OR=2.84, 95% CI=1.19-6.79, P=0.02).
  
  
  CONCLUSIONS
  Vasopressin use in the resuscitation of cardiac arrest patients is not associated with any overall benefit or harm. However, vasopressin may improve the long-term survival of asystolic patients, especially when average T(DRUG) is <20 min.
authors.affiliation: First Department of Pulmonary and Critical Care Medicine, University of Athens Medical School, Evaggelismos General Hospital, 45-47 Ipsilandou Street, GR-10675 Athens, Greece. sdm@hol.gr
authors.forename: Spyros D
authors.initials: SD
authors.lastname: Mentzelopoulos
authors.forename: Spyros G
authors.initials: SG
authors.lastname: Zakynthinos
authors.forename: Ilias
authors.initials: I
authors.lastname: Siempos
authors.forename: Sotiris
authors.initials: S
authors.lastname: Malachias
authors.forename: Hanno
authors.initials: H
authors.lastname: Ulmer
authors.forename: Volker
authors.initials: V
authors.lastname: Wenzel
mesh_terms: D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D014943:Global Health; D006323:Heart Arrest / Q000401:mortality / Q000628:therapy*; D006801:Humans; D016032:Randomized Controlled Trials as Topic; D015996:Survival Rate / Q000639:trends; D014662:Vasoconstrictor Agents / Q000627:therapeutic use; D014667:Vasopressins / Q000627:therapeutic use*
chemical_list: D014662:Vasoconstrictor Agents; D014667:Vasopressins