Hypotensive anaesthesia for microsurgery of the middle ear. A comparison between isoflurane and halothane.
Fifty patients undergoing microsurgery of the ear were anaesthetised using thiopentone, nitrous oxide, oxygen and either halothane or isoflurane, via a low flow circle system with carbon dioxide absorption. Systolic blood pressure was reduced to approximately 70 mmHg by the additional use of increments of labetalol; the patients breathed spontaneously. The degree of haemostasis was assessed by the surgeon who was unaware which volatile agent was being used to supplement anaesthesia. Isoflurane, although it is a potent vasodilator produced operating conditions which were indistinguishable from halothane. Isoflurane is thus a safe and reliable alternative to halothane as a volatile agent used to supplement anaesthesia when using induced hypotension for middle ear surgery.
D000293:Adolescent; D000328:Adult; D000368:Aged; D000769:Anesthesia, Inhalation; D002648:Child; D004432:Ear, Middle / Q000601:surgery*; D005260:Female; D006221:Halothane; D006801:Humans; D007023:Hypotension, Controlled; D007530:Isoflurane; D007741:Labetalol / Q000008:administration & dosage; D008297:Male; D008738:Methyl Ethers; D008866:Microsurgery; D008875:Middle Aged
D008738:Methyl Ethers; D007530:Isoflurane; D007741:Labetalol; D006221:Halothane