Power, Marschelle H.

Daily water metabolism of 21 patients was studied for 3 days after intracardiac surgery and whole-body perfusion. The average obligatory water losses of these patients were approximately 500, 750, and 750 ml. per M. 2 of body surface per day on the first, second, and third postoperative day, respectively. A simple system, which combines knowledge of the estimated postoperative water requirement with the known daily change in body weight, was devised to manage accurately water metabolism after intracardiac surgery.

Each of 21 patients was noted to have a low concentration of water in the serum immediately after whole-body perfusion. This indicated a loss of water either by the patient or the pump-oxygenator. Investigation suggested that the patient, and not the pump-oxygenator, was the source of water loss. Two of the 21 patients had a profuse, short-lived solute diuresis in the immediate postperfusion period. These phenomena are apparently benign and they require no specific treatment.