Lidocaine attenuates the intraocular pressure response to rapid intubation in children.

Abstract

To determine the effect of intravenous lidocaine on the intraocular pressure (IOP) response to laryngoscopy and intubation, twenty unpremedicated children, ages one to ten years were studied. After administration of either intravenous sterile water (control) (n = 10) or preservative-free lidocaine (1.5 mg X kg-1) (n = 10), anaesthesia was induced with pancuronium (0.15 mg X kg-1), thiopentone (5 mg X kg-1), and atropine (0.02 mg X kg-1), and maintained with halothane, nitrous oxide and oxygen. The trachea was intubated one minute after administration of thiopentone. IOP (measured by applanation tonometry), heart rate, and systolic blood pressure were measured at the time of loss of the eyelid reflex (time 0), immediately after endotracheal intubation, and each minute thereafter for five minutes. In the control group, IOP increased (27 per cent) significantly after intubation (p less than 0.05), whereas in the lidocaine group, IOP did not increase (9.8 per cent) significantly after intubation. IOP decreased below time 0 values within three minutes after loss of the eyelid reflex in the lidocaine group (p less than 0.05). At each measurement (except time 0), IOP was significantly greater in the control group than in the lidocaine group (p less than 0.05). Heart rate and systolic blood pressure did not increase significantly in either group after intubation. We conclude that intravenous lidocaine (1.5 mg X kg-1) significantly attenuates the IOP response to laryngoscopy and intubation in children anaesthetized with pancuronium, thiopentone, and atropine.