AMINOPHYLLINE AS AN ADJUNCT TO STANDARD ADVANCED CARDIAC LIFE-SUPPORTIN PROLONGED CARDIAC-ARREST

Study hypothesis: We hypothesized that the addition of aminophylline t o Advanced Cardiac Life Support (ACLS) interventions would improve the initial resuscitation success rate in an animal model of prolonged ca rdiac arrest. Methods: We used a double-blind, placebo-controlled, ran domized-black design with a follow-up open-label uncontrolled phase. W e studied 24 female domestic mixed-breed swine (body mass, 20 to 25 kg ). After electrical induction of ventricular fibrillation, animals wer e subjected to 8 minutes of no-flow cardiac arrest followed by 1 minut e of mechanical ventilation and closed-chest compressions. Nine minute s after arrest, equal numbers of swine received 6 mg/kg intravenous am inophylline (treatment group) and a saline solution placebo (control g roup), another minute of basic CPR, and standardized ACLS intervention s beginning at 10 minutes. Initial resuscitation efforts were continue d far at least 20 minutes. In all animals, if initial efforts failed, 6.0 mg/kg intravenous aminophylline, open label, and 10 minutes of add itional resuscitation were administered. The primary outcome variables were return of spontaneous circulation (ROSC) and 1-hour survival. We compared groups with the two-tailed Fisher exact test. Results: ROSC occurred in 4 of 12 animals in the treatment group (33%) and 3 of 12 i n the control group (25%) (P=.50). Late administration of aminophyllin e did not result in ROSC in any animal. Survival to 1 hour was greater in the treatment group (4 of 12, 33%) than in the control group (1 of 12, 8%) (P=.16). Conclusion: Addition of aminophylline to standard AC LS interventions did not increase the incidence of ROSC or the 1-hour survival rate in a swine model of prolonged cardiac arrest.