STUDY HYPOTHESIS: We hypothesized that the addition of aminophylline to Advanced Cardiac Life Support (ACLS) interventions would improve the initial resuscitation success rate in an animal model of prolonged cardiac arrest. METHODS: We used a double-blind, placebo-controlled, randomized-block design with a follow-up open-label uncontrolled phase. We studied 24 female domestic mixed-breed swine (body mass, 20 to 25 kg). After electrical induction of ventricular fibrillation, animals were subjected to 8 minutes of no-flow cardiac arrest followed by 1 minute of mechanical ventilation and closed-chest compressions. Nine minutes after arrest, equal numbers of swine received 6 mg/kg intravenous aminophylline (treatment group) and a saline solution placebo (control group), another minute of basic CPR, and standardized ACLS interventions beginning at 10 minutes. Initial resuscitation efforts were continued for at least 20 minutes. In all animals, if initial efforts failed, 6.0 mg/kg intravenous aminophylline, open label, and 10 minutes of additional 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 in the control group (25%) (P=.50). Late administration of aminophylline 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 ACLS interventions did not increase the incidence of ROSC or the 1-hour survival rate in a swine model of prolonged cardiac arrest.
STUDY HYPOTHESIS: We hypothesized that the addition of aminophylline to Advanced Cardiac Life Support (ACLS) interventions would improve the initial resuscitation success rate in an animal model of prolonged cardiac arrest. METHODS: We used a double-blind, placebo-controlled, randomized-block design with a follow-up open-label uncontrolled phase. We studied 24 female domestic mixed-breed swine (body mass, 20 to 25 kg). After electrical induction of ventricular fibrillation, animals were subjected to 8 minutes of no-flow cardiac arrest followed by 1 minute of mechanical ventilation and closed-chest compressions. Nine minutes after arrest, equal numbers of swine received 6 mg/kg intravenous aminophylline (treatment group) and a saline solution placebo (control group), another minute of basic CPR, and standardized ACLS interventions beginning at 10 minutes. Initial resuscitation efforts were continued for at least 20 minutes. In all animals, if initial efforts failed, 6.0 mg/kg intravenous aminophylline, open label, and 10 minutes of additional 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 in the control group (25%) (P=.50). Late administration of aminophylline 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 ACLS interventions did not increase the incidence of ROSC or the 1-hour survival rate in a swine model of prolonged cardiac arrest.