Aminophylline for bradyasystolic cardiac arrest in adults

Background: In cardiac ischaemia, the accumulation of adenosine may lead to or exacerbate bradyasystole and diminish the effectiveness of catecholamines administered during resuscitation. Aminophylline is a competitive adenosine antagonist. Case studies suggest that aminophylline may be effective for atropine-resistant bradyasystolic arrest. Objectives: To determine the effects of aminophylline in the treatment of patients in bradyasystolic cardiac arrest, primarily survival to hospital discharge. We also considered survival to admission, return of spontaneous circulation, neurological outcomes and adverse events. Search methods: We searched the Cochrane Central Register of Controlled Trials (CENTRAL; The Cochrane Library, Issue 4, 2009), MEDLINE, EMBASE, CINAHL, LILACS, ClinicalTrials.gov and WHO International Clinical Trials Registry Platform. We checked the reference lists of retrieved articles, reviewed conference proceedings, contacted experts and searched further using Google. The search strategy was updated in March 2012. Selection criteria: All randomised controlled trials comparing intravenous aminophylline with administered placebo in adults with non-traumatic, normothermic bradyasystolic cardiac arrest who were treated with standard advanced cardiac life support (ACLS). Data collection and analysis: Two review authors independently reviewed the studies and extracted the included data. We contacted study authors when needed. Pooled risk ratio (RR) was estimated for each study outcome. Subgroup analysis was predefined according to the timing of aminophylline administration. Main results: Five trials are included in this analysis, all of which were performed in the prehospital setting. The risk of bias was low in four of these studies (n = 1186). The trials accumulated 1254 participants. Aminophylline was found to have no effect on survival to hospital discharge (RR 0.58, 95% confidence interval (CI) 0.12 to 2.74) or on secondary survival outcome (survival to hospital admission: RR 0.92, 95% CI 0.61 to 1.39; return of spontaneous circulation: RR 1.15, 95% CI 0.89 to 1.49). Survival was rare (6/1254), making data about neurological outcomes and adverse events quite limited. The planned subgroup analysis for early administration of aminophylline included 37 participants. No one in the subgroup survived to hospital discharge. Authors' conclusions: The prehospital administration of aminophylline in bradyasystolic arrest is not associated with improved return of circulation, survival to admission or survival to hospital discharge. The benefits of aminophylline administered early in resuscitative efforts are not known.