SPONTANEOUS RESPIRATION VERSUS CONTROLLED VENTILATION ANESTHESIA WITHHALOTHANE FOR INTRAOCULAR SURGERY

One hundred and thirty-seven patients were randomly allocated to recei ve halothane anaesthesia for intraocular surgery either by IPPV (n=71) or breathing spontaneously (n=66). Both techniques provided satisfact ory operating conditions in 87% and 80% of procedures, respectively. I ntra-ocular pressure was reduced in a similar majority of patients, ro se in a similar percentage (spontaneous = 11%, controlled = 21%) and r emained unchanged in a few. Surgeons' reports of good operative condit ions correlated very well with intra-ocular pressure changes whether t hey rose or fell intra-operatively. The duration of anaesthesia and th e time taken to achieve full recovery following the two techniques wer e similar. Post-operative vomiting, headache, sore throat and confusio n occurred with similar frequency, and analgesic and antiemetic requir ements were not influenced by the technique. Resumption of ambulation, oral intake and micturation occurred similarly. In both groups, patie nts with a low normal pre-operative intra-ocular pressure tended to sh ow a rise in intra-ocular pressure during anaesthesia, and those with a high normal pre-operative intra-ocular pressure tended to show a fal l.