BACKGROUND: During ophthalmologic surgery, various intravenous anesthetic induction agents are used to prevent an intraocular pressure (IOP) increase. This study was designed to compare the effects of etomidate on IOP with those of thiopental sodium and propofol in patients receiving vecronium bromide, and in whom tracheal intubation was performed.

METHODS: Forty-five patients undergoing elective surgery were ramdomized to receive etomidate 0.3 mg/kg (E group, n = 15), thiopental sodium 5 mg/kg (T group, n = 15) or propofol 2.5 mg/kg (P group, n = 15). IOP, systolic arterial pressure (SAP) and heart rate (HR) were measured before induction (B), after the adminstration of the induction agents (I₁), before intubation (I₂) and at 1, 2 and 3 mins after intubation (T₁, T₂ and T3).

RESULTS: The IOP after I₁ and I₂ in the E , T and P groups were significantly lower than in group B (P < 0.05). The IOP at T₁, T₂ and T3 in the E, T and P groups were not found to be significantly different from group B. The IOP, SAP and HR at T₁, T₂, and T3 in the E, T and P groups were significantly higher than at I₁ and I₂ (P < 0.05). No significant differences were observed between the groups in term of IOP. The SAP and HR at T₁, T₂ and T3 in the P group were significantly lower than in the other two groups (P < 0.05).

CONCLUSIONS: We concluded that etomidate, thiopental sodium and propofol may be useful induction agents for general anesthesia in ophthalmologic surgery but that they do not prevent IOP elevation during endotracheal intubation.