Hypothermia: an under-estimated risk

Abstract

Prof. Bruno: A 80-year-old woman was found unconscious in the street from a passer-by. It was a cold January morning, and the patient had slept outdoor. She was a homeless known in the Emergency Department (ED) as an alcohol abuser. When she was admitted to the ED, she presented with stupor and apathy. She spoke very slowly, and her speech patterns were vague and slurred. Physical examination revealed that the skin was very cold, even on the torso; and there was marked pallor. The rectal body temperature was 29 C. She had an abnormally slow rate of breathing (8 breaths/ min), and the non-invasive SO2 was 86% on room air, and 96% after the administration of Oxygen by mask (6 L min). Blood pressure was 85/50 mmHg, and the pulse was 40 beats/min, and very weak. The 12-lead ECG showed sinus bradycardia at about 40 beats/min, and there were prominent J waves (Osborn Wave). Hemogasanalytic values were normal. A Glasgow Coma Scale (GCS) score was 10. The patient underwent oro-tracheal intubation to provide airway protection. The finger-stick glucose was normal (108 mg %). The laboratory tests were within normal ranges except for a hyponatremia (120 mmol/L). We hypothesize the hyponatremia was due to volume depletion. Our working diagnosis was accidental hypothermia. We immediately removed her wet cold clothing, and we covered the patient with an electric blanket. She was given warm saline fluids intravenously. Because she was classified as severe hypothermia with a high risk for cardiac arrest, she underwent extra-corporeal treatment by emergency haemodialysis to actively rewarm her blood rapidly outside the body. In this way it was possible to restore normal body temperature rapidly. This invasive method of rewarming permitted us to restore a normal core temperature providing safe treatment. The patient left the hospital after several; days in good health. We advised her to avoid sleeping outside, to adequately cover her body including extremities and particularly the head.