COMPARISONS OF PROLONGED SEVOFLURANE, ISOFLURANE, AND HALOTHANE ANESTHESIA COMBINED WITH NITROUS-OXIDE IN SPONTANEOUSLY BREATHING CATS

The clinical, cardiopulmonary, haematologic, and serum biochemical eff ects of sevoflurane, isoflurane and halothane anaesthesia with 66% nit rous oxide, were compared in healthy, premedicated cats breathing spon taneously during 6 h of anaesthesia. Recovery time from anaesthesia wi th sevoflurane-nitrous oxide was more rapid than that with halothane-n itrous oxide, but it does not differ from that with isoflurane-nitrous oxide. The degree of respiratory acidosis with sevoflurane-nitrous ox ide anaesthesia was similar to that with isoflurane-nitrous oxide and was less than that with halothane-nitrous oxide. There were no signifi cant differences among the groups in the heart rate, arterial pressure s, haematological and serum biochemical values. The three anaesthetic regimens induced a similar degree of hyperglycemia during anaesthesia. Serum biochemical examination did not reveal apparent hepatic or rena l injuries after each anaesthesia. Time-related increases in respirati on rate and arterial carbon dioxide partial pressure were observed dur ing prolonged halothane-nitrous oxide anaesthesia. No significant time -related changes in cardiopulmonary variables were observed during eit her sevoflurane- or isoflurane-nitrous oxide anaesthesia. Therefore, s evoflurane-nitrous oxide may be used as an effective and safe anaesthe tic combination similar to isoflurane-nitrous oxide for long-term anae sthesia in healthy cats.