INADAPTABILITY OF ACTUAL ELIMINATION OF HALOTHANE TO THEORETICAL WASHOUT FORMULA
Five mongrel dogs were anesthetized with 70 % of nitrous oxide, 1 % of halothane and balanced oxygen for 2 hours and they were ventilated under adequate ventilatory volume (15 ml /kg) throughout by a piston respirator. Thereafter the halothane anesthesia was ceased and the animals were anesthetized merely with nitrous oxide and oxygen under the same ventilatory condition. The amount of halothane eliminated in their expired gas was measured for the subsequent 3 hours continuously. Transient increases in elimination of halothane were noted approximately at 40 and 60 minutes after the cessation of halothane breathing. The first increase may be influenced by the maximal increase in the cardiac output. The second increase was assumed to be attributable to abrupt changes of blood perfusion into tissues where a large quantity of the halothane was taken up.