Cardiovascular effects of ketamine following administration of aminophylline in dogs

The induction of halothane anesthesia following intravenous administration of aminophylline may cause ventricular arrhythmias. Ketamine has been recommended for anesthesia induction and maintenance in patients with asthma. This study was designed to determine whether induction and maintenance of ketamine anesthesia following intravenous aminophylline is arrhythmogenic in dogs. One group of six dogs was anesthetized with intravenous ketamine, 5 mg/kg, followed by infusion of 5 mg/kg/hr. Three additional groups of six dogs were given intravenous aminophylline, 10, 25, and 50 mg/kg, respectively, followed 3 minutes later by intravenous ketamine, 5 mg/kg, and a 5 mg/kg/hr ketamine infusion. No arrhythmias occurred at any time in any animal. Ketamine use following aminophylline would appear to lack arrhythmogenic potential and may be advantageous in the clinical setting.