Desflurane maintains intraocular pressure at an equivalent level to isoflurane and propofol during unstressed non-ophthalmic surgery

Abstract

We have investigated the effects of desflurane compared with isoflurane and propofol on intraocular pressure (IOP) in 48 ASA I-II patients undergoing elective non-ophthalmic surgery. Anaesthesia was induced with thiopental 3-5 mg kg-1, fentanyl 2-4 micrograms kg-1 and vecuronium 0.1 mg kg-1. Patients were allocated randomly to receive propofol (n = 16) 4-8 mg kg-1 h-1, isoflurane (n = 16) or desflurane (n = 16) for maintenance of anaesthesia. Fentanyl was added if necessary. The lungs were ventilated with 70% nitrous oxide in oxygen. Arterial pressure, electrocardiography, heart rate and end-tidal carbon dioxide were measured throughout anaesthesia. IOP was measured before surgery, during maintenance and after emergence from anaesthesia with applanation tonometry by an ophthalmologist blinded to the anaesthetic technique. There was a significant decrease in IOP after induction of anaesthesia which did not differ between groups. Desflurane maintained IOP at an equivalent level to isoflurane and propofol.