Comparison of the Effect of Rocuronium and Succinylcholine on Intraocular Pressure during General Anaesthesia: A Randomised Clinical Trial

Abstract

Background: Succinylcholine remains unsurpassed in providing ideal intubating conditions in the shortest time among all available neuromuscular blocking agents and hence is advocated as the drug of choice for rapid sequence endotracheal intubation. However, an increase in intraocular pressure ( IOP ) is one of its undesirable effects, especially in patients with open eye injury. Rocuronium is a nondepolarising neuromuscular blocking drug which provides rapid onset of action in a dosage of 0.9 to 1.2mg/kg. Absence of tonic contraction of extraocular muscles precludes any increase in IOP following administration of Rocuronium. However very few studies have studied the effect of Rocuronium on IOP. Hence this study was done to compare effect of Succinylcholine and Rocuronium on IOP during general anaesthesia. Objective: To compare the effect of Rocuronium and Succinylcholine on intraocular pressure during general anaesthesia. Study design: Randomized clinical trial. Methods: 40 patients of either sex, in the age group of 18-50 years scheduled to undergo non-ophthalmologic surgeries under general anaesthesia after meeting inclusion and exclusion criteria were enrolled for the study. The patients were randomly allocated to two groups ( Group R=20 patients ) and ( Group S=20 patients ) . In group S, patients received Succinylcholine 1.5mg/kg and in group R, Rocuronium 0.9mg/kg for tracheal intubation following standard induction protocol. IOP was measured using Schioetz tonometer at baseline, 60 sec after relaxant, 1min, 3min and 5min after intubation. IX Results: While there was an increase in IOP with the administration of Succinylcholine, with Rocuronium there was a significant decrease in IOP. Conclusion: Rocuronium does not cause a significant increase in IOP, in fact causes a decrease in IOP whereas Succinylcholine causes an increase in IOP. Rocuronium hence appears to be the muscle relaxant of choice in patients with penetrating eye injuries requiring rapid sequence induction with tracheal intubation.