Carbon dioxide output in spontaneously breathing infants during anaesthesia and surgery

Twenty-eight infants were anaesthetized with halothane, nitrous oxide and oxygen and allowed to breathe spontaneously through a non-rebreathing system during minor paediatric surgery. Carbon dioxide output was correlated negatively with body weight for infants greater than 10 kg, but not for children less than 10 kg. Carbon dioxide output was unchanged compared with before surgery.