Survival with severe hypernatremia.

In a 74-year-old woman, excessive insensible water loss developed secondary to a period of hot, humid weather, associated with an underlying inability to obtain adequate water replacement. On admission to the hospital she was comatose, clinically dehydrated, and had laboratory values consistent with a water deficit of approximately 30% (9 L) of body water. Serum sodium concentration was 202 mEq/L. Serum osmolality was 430 mOsm/L. The patient remained comatose for seven days, during which time she was vigorously treated with fluids, and she gradually recovered. This case represents what we believe is a unique report in the literature of the severity of hypernatremia developing via this pathogenic mechanism and survival in an adult with this degree of disturbance of sodium and water homeostasis.