Propofol and alfentanil prevent the increase in intraocular pressure caused by succinylcholine and endotracheal intubation during a rapid sequence induction of anesthesia.

The increase in intraocular pressure (IOP) associated with succinylcholine (Sch) has made its use in patients with open globe injuries controversial. Studies that have examined techniques to prevent the increase in IOP due to Sch have shown a larger increase in IOP from the stimulus of laryngoscopy and endotracheal intubation. The purpose of our study was to examine whether the combination of propofol and alfentanil would prevent the increase in IOP due to Sch as well as endotracheal intubation during a rapid sequence induction of anesthesia. Sixty patients were randomized to receive either thiopental 5 mg/kg and Sch 1.5 mg/kg (Group I), propofol 2 mg/kg and Sch 1.5 mg/kg (Group II), or propofol 2 mg/kg, alfentanil 40 micrograms/kg, and Sch 1.5 mg/kg (Group III). The IOP was measured continuously from baseline awake (control) values until 15 s after successful intubation. All three groups had a significant decrease in IOP with the induction of anesthesia. Succinylcholine produced a consistent increase in IOP from the postinduction low in Groups I and II, but this increase was not significantly higher than baseline. The postintubation IOPs in Groups I and II were significantly higher than baseline (P < 0.001). During the entire study period, the IOP in Group III never increased above baseline. The IOP in Groups I and II had already begun to decline by 15 s postintubation, suggesting that laryngoscopy and intubation have the greatest effect on increasing IOP. We conclude that the combination of propofol and alfentanil prevents the increase in IOP from Sch as well as the increase associated with endotracheal intubation during a rapid sequence induction of anesthesia.