Comparison of Intraocular Pressure and Hemodynamic Response Subsequent to Tracheal Tube versus Laryngeal Tube Insertion during General Anesthesia

It is well accepted that intraocular pressure should be controlled during general anesthesia (G/A) for intraocular procedures. This study was performed to compare the effects of the laryngeal and tracheal tubes on intraocular pressure (IOP), mean arterial pressure (MAP) and heart rate (HR) during the course of G/A. Eighty adult patients were randomly allocated to two groups for cataract surgery. Group A (n=40) underwent laryngeal tube (LT) placement and group B (n=40) had tracheal tube (TT) insertion. Anesthesia was induced by midazolam, fentanyl, propofol and atracurium and was maintained by propofol and 50% nitrous oxide in oxygen. IOP, MAP and HR were measured before and 3 minutes after induction of G/A, 1 and 5 minutes after tube placement, at the end of the operation, and 1 minute after extubation. The IOP at 1 minute after removal of the tubes was significantly higher in the TT group than the LT group. The MAP at 1 minute and heart rate at 1 and 5 minutes after placement of the tubes were significantly higher in TT group than the LT group. In the course of G/A, using the same anesthetic agents such as propofol, and atracurium, LT had better control than TT on IOP, MAP and HR.