The Osborn Wave in Accidental Hypothermia

Abstract

Hypothermia is generally defined as a core body temperature less than 35°C (95°F), and is one of the most common environmental emergencies encountered by emergency physicians. A 32-year-old male hunter was admitted to the hospital with altered mental status. He remained unconscious, Glasgow Coma Scale (GCS) score was recorded as 5/15, and pupils were dilated and unreactive. His vital signs showed a heart rate of 48 beats/min, respiratory rate of 10 breaths/min, blood pressure of 95/50 mm Hg, and rectal temperature of 31°C. An electrocardiogram (ECG) was obtained and showed marked sinus bradycardia and J waves. His finger-stick glucose was 85. He was intubated. After 3 h of active rewarming, his temperature was 34°C, and the repeat ECG showed near-complete resolution of the J waves and acceleration of the sinus rate to 68 beats/min. At the same time, emergency head computed tomography (CT) scan showed subarachnoid hemorrhage (SAH) and subdural hemorrhage. The patient died on the third day of admission. In this case we want to indicate that J waves and obtunded state could be due to either SAH or hypothermia, and SAH could have been missed if initial obvious hypothermia had been believed to cause all symptoms.