Comparison between rocuronium and suxamethonium muscle relaxants in ocular trauma surgery.

BACKGROUND: Suxamethonium causes a rise in intraocular pressure (IOP). Its use for intraocular surgical procedures especially management of the penetrating eye injury is controversial because of the risk of extrusion of vitreous contents. This risk can be avoided by substituting it with rocuronium. The aim of this study was to compare the IOP changes and intubating conditions following the use of both muscle relaxants. AIM AND OBJECTIVES: To compare the intraocular pressure changes and intubating conditions following the use of both suxamethonium and rocuronium. DESIGN OF STUDY: Prospective, randomized, double-blind study. STUDY SETTING: The operating theatres of the Lagos University Teaching Hospital Patients and Methods: A prospective, randomized study in which 70 patients received suxamethonium 1.5mg/kg or rocuronium 0.9mg/kg after induction with thiopentone 5mg/kg. Laryngoscopy was performed after 60 seconds. Measurements of IOP were taken before induction, 1 minute after administration of either muscle relaxant and at 1, 3 and 5 minutes after intubation. Intubating conditions were evaluated using a simple scoring system. RESULTS: Suxamethonium caused a significant rise in intraocular pressure throughout the study period (p < 0.005), maximal 1 minute after intubation (p < 0.001). Rocuronium caused a significant fall in intraocular pressure 1 minute after administration (p < 0.001) and this remained less than the baseline value in the post intubation period. Intubating conditions in both groups were similar. CONCLUSION: Rocuronium is preferred as muscle relaxant for tracheal intubation when a rise in intraocular pressure is undesirable.