Respiratory function and acid-base status in accidental hypothermia assessed by arterial blood gas analysis

To study the respiratory function and acid-base status in hypothermia, we retrospectively reviewed data of arterial blood gas analysis obtained from 63 patients with accidental hypothermia on admission. Twenty-nine showed acidemia and 16 showed alkalemia. The following results were obtained from 57 patients in whom blood gas analysis was performed in room air. PaCO2 was 46 mmHg or more in 2 and 34 mmHg or less in 46. Most of the patients exhibiting acidemia had metabolic acidosis except 2 with severe pneumonia or subdural hematoma. PaCO2 was low even in the patients with alkalemia. PaO2 was 60 mmHg or less in 8, of whom 7 had pneumonia, and 70 mmHg or more in most of the patients without pneumonia. We found that patients with accidental hypothermia generally showed a respiratory function proportionate to their decreased metabolism or hyperventilation, and most of the patients with acidemia exhibited metabolic acidosis.