Management of severe hypothermia and pulsus alternans in an anaesthetised cat

Abstract

An 8-year-old, domestic, shorthair cat was presented for management of a significant degloving injury. After initial wound management, the cat was scheduled for anaesthesia to allow a free skin and pad graft to the affected foot. During anaesthesia, temperature rapidly dropped to a nidus of 28.0 • C. Associated with this, the cat developed bradycardia and a marked pulsus alternans. The presumed ventricular myocardial dysfunction was treated with pimobendan (0.15 mg/kg intravenously). Within 5 minutes, the pulses equalised in amplitude. Additional active rewarming measures were initiated, which raised the temperature to 36.4 • C before recovery in an incubator. A urinary catheter was placed to monitor for cold diuresis, and fluid therapy was altered to match urine output for 12 hours. A post-anaesthetic echocardiogram revealed mild left ventricular concentric hypertrophy and dynamic right ventricular outflow tract obstruction indicating mild hypertrophic cardiomyopathy. The cat was discharged following 3 weeks of successful intensive wound and graft management.