Changes of the postoperative minimal oxygen consumption of the newborn.

Minimal oxygen consumption and carbon dioxide production were studied in newborns without operation and with minor or major operation by means of open indirect calorimetry. (1) A postnatal increase in the mVO2 was observed in most of the full-term newborns without operation or with minor operation. (2) A postoperative increase in the mVO2, as observed in the adult, was not found in all newborns with a major operation. (3) This finding was particularly obvious in the newborn with a major abdominal operation and with a long pre- and postoperative periods of starvation. (4) The most important factor determining the postoperative decrease in the mVO2 is not the intensity of operative stress but the amount of caloric intake.