Propofol or thiopentone: effects on intraocular pressure associated with induction of anaesthesia and tracheal intubation (facilitated with suxamethonium).

Changes in intraocular pressure (IOP) were studied in patients given propofol 2.1 mg kg-1 (n = 30) or thiopentone 4.9 mg kg-1 (n = 30) followed by suxamethonium 1.0 mg kg-1 and tracheal intubation. Half the patients in each group received an additional smaller dose of the same induction agent (propofol 1.0 mg kg-1 or thiopentone 2.0 mg kg-1) immediately before intubation. Both agents produced significant decreases in IOP which were slightly more marked with propofol. The administration of suxamethonium produced an increase in IOP in all groups, more so in those given thiopentone, in whom it exceeded the control values. Intubation of the trachea produced the greatest increase in IOP, averaging about 25% above control in all groups except in the group given the additional dose of propofol, in whom IOP remained below control values throughout the process of induction and intubation. Ten patients (33%) experienced pain on injection with propofol. A decrease in systolic arterial pressure of more than 30% was observed in 12 patients (40%) receiving propofol, compared with three (10%) of those given thiopentone.