Hypotensive anaesthesia for microsurgery of the middle ear. A comparison between enflurane and halothane

One hundred patients undergoing microsurgery of the ear were anaesthetised using thiopentone, nitrous oxide, oxygen and either halothane or enflurane with spontaneous respiration. Blood pressure was reduced to approximately 70 mmHg by the use of hypotensive agents. The efficacy of halothane and enflurane in producing good operating conditions was compared during this technique. Haemostasis was assessed by the surgeon who was unaware which volatile agent was being used. Both agents were found to be satisfactory and enflurane was shown to be a safe and reliable agent with this technique should an alternative to halothane be required. No impairment of renal function was seen with either agent in combination with hypotension.