COMPARATIVE STUDY BETWEEN THE EFFECTS OF THE USE OF LARYNGEAL MASK AIRWAY AND ENDOTRACHEAL INTUBATION ON STRESS RESPONSE AND INTRAOCULAR PRESSURE IN GLAUCOMATOUS PATIENTS

Abstract

Patients with glaucoma are at high risk of ocular complications and loss of vision especially if the intraocular pressure gets higher. These patients are usually adults or elderly, so hemodynamic changes associated with stress response may be detrimental. This study was conducted on eighty patients, 45-65 years old, ASA I or II, undergoing elective ophthalmic surgery. Halfofthe patients were glaucomatous and the other half were non-glaucomatous. . All patients received midazolam 2 mg IV and fentanyl 1 f.1g/kg IV as premedication. Anaesthesia was induced by propofol2.5 mg!kg and atracurium 0.5 mg!kg. Anaesthesia was maintained by isoflurane and 021N20 gas mixture. The following parameters were be assessed for all patients: Heart rate and rhythm, non-invasive blood pressure, end-tidal C02 and peripheral oxygen saturation. Serum cortisol (as an indicator for hormonal stress response) before induction and 10 minutes after laryngeal mask airway insertion or tracheal intubation. Intraocular pressure before and after induction of anaesthesia and immediately after laryngeal mask placement or tracheal intubation. The results of this study showed that there was hemodynamic stability during laryngeal mask airway placement when compared with tracheal intubation. The end-tidal C02 and peripheral oxygen saturation were nearly the same in all groups. Sermn cortisol did not increase after laryngeal mask airway placement but it showed a significant increase after tracheal intubation. Intraocular tension decreased after induction but showed a significant increase after tracheal intubation that did not occur after laryngeal mask airway placement.