PROLONGED SEVOFLURANE, ISOFLURANE AND HALOTHANE ANESTHESIA IN OXYGEN USING REBREATHING OR NON-REBREATHING SYSTEM IN CATS

Effects of prolonged sevoflurane, isoflurane and halothane anaesthesia in oxygen on clinical, cardiopulmonary, haematologic, and serum bioch emical findings were compared in healthy, premedicated cats breathing spontaneously during 6 h of anaesthesia using rebreathing (semi-closed circuit) or non-rebreathing (Bain coaxial circuit) system. Recovery f rom anaesthesia with sevoflurane was more rapid than that with halotha ne or isoflurane in both systems. Respiration and heart rates during s evoflurane anaesthesia were similar to those during isoflurane rather than halothane anaesthesia in both systems. The degree of respiratory acidosis during prolonged sevoflurane anaesthesia was similar to that during isoflurane anaesthesia, and was less than that during halothane anaesthesia in both rebreathing and non-rebreathing systems. Prolonge d sevoflurane anaesthesia induced mean arterial pressure similar to is oflurane or halothane anaesthesia in the non-rebreathing system, but i t depressed mean arterial pressure less than isoflurane or halothane a naesthesia in the rebreathing system. Time-related increase in the art erial carbon dioxide partial pressure was observed during halothane an aesthesia especially in the rebreathing system, however, no significan t time-related changes in cardiopulmonary variables were observed duri ng either sevoflurane or isoflurane anaesthesia in both systems. There were no significant differences among sevoflurane, isoflurane and hal othane anaesthesia in serum biochemical values in both systems.