DEXMEDETOMIDINE REDUCES INTRAOCULAR PRESSURE, INTUBATION REPONSES AND ANAESTHETIC REQUIREMENTS IN PATIENTS UNDERGOING OPHTHALMIC SURGERY

• Published in: British journal of anaesthesia : BJA Vol. 68; no. 6; pp. 570 - 575
• Main Authors: JAAKOLA, M.-L., ALI-MELKKILÄ, T., KANTO, J., KALLIO, A., SCHEININ, H., SCHEININ, M.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.1992; Oxford University Press
• Subjects: dexmedetomidine; Eye: intraocular pressure; Intubation; Sympathetic nervous system: α adrenergic agonist; tracheal: sympathoadrenal response; dexmedetomidine; Sympathetic nervous system: α adrenergic agonist; Intubation; tracheal: sympathoadrenal response; Eye: intraocular pressure
• ISSN: 0007-0912; 1471-6771
• DOI: 10.1093/bja/68.6.570

We studied the effects of a single i.v. dose of dexmedetomidine, a highly selective and specific alpha2 adrenoceptor agonist, on intraocular pressure (IOP), haemodynamic and sympathoadrenal responses to laryngoscopy and tracheal intubation, and on anaesthetic requirements in ophthalmic surgery. Thirty ASA I–II patients undergoing cataract surgery were allocated randomly to receive either dexmedetomidine 0.6 μg kg−1 or saline placebo i.v. 10 min before induction of anaesthesia in a double-blind design. After dexmedetomidine there was a 34% (95% confidence interval (Cl) 27–43%) reduction in IOP (P<0.001) and 62% (Cl 57–68%) decrease in plasma noradrenaline concentrations (P<0.001). After intubation, maximum heart rate was 18% (Cl 3–33%, P=0.036) and the maximum IOP 27% (Cl 11–43%. P=0.005) less in the dexmedetomidine group compared with the patients treated with placebo. Within 10 min after intubation, maximum systolic and diastolic arterial pressures were also significantly (P=0.013 and P=0.020) smaller in the dexmedetomidine group. The induction dose of thiopentone was smaller (23% (Cl 20–26%) P=0.012), and the use of isoflurane or fentanyl supplements during anaesthesia was less frequent in the dexmedetomidine group. The patients premedicated with dexmedetomidine recovered faster from anaesthesia (P=0.042). These results suggest that dexmedetomidine may be a useful anaesthetic adjunct in ophthalmic surgery.