Effect of sevoflurane versus isoflurane on middle ear pressure during tonsillectomy operation

Abstract EN

Background Increase in middle ear pressure (MEP) (mm H2O) is an undesirable condition because of its potential complications.

The aim of this randomized study was to compare the effects of isofl urane and sevofl urane on MEP.

Patients and methods Patients in American Society of Anesthesiologists ( ASA) group I–II between 6 and 14 years of age undergoing tonsillectomy operation were randomized into two groups.

Group 1 received isofl urane and group 2 received sevofl urane for maintenance of anesthesia after induction with thiopental and suxamethonium in both groups.

MEPs were measured and recorded 1 day before the operation (T0), with the patient lying supine on the operating table (T1), after the induction of anesthesia and endotracheal intubation (T2), and soon after withdrawal of anesthesia (T3).

Finally, MEP values were compared intragroup with the baseline value (T0) and between groups.

Results In comparison with the baseline value in T0, MEP was signifi cantly increased in T1, T2, and T3 in the two groups.

There were no differences between groups at all times, but at the end of anesthesia at T3, the increase in MEP was signifi cantly lower in group 1 (isofl urane group) than in group 2 (sevofl urane groups) (103 ± 68 vs.

138 ± 99, P < 0.01 in the right ear and 112 ± 82 vs.

141 ± 101, P < 0.01 in the left ear).

Conclusion There was an increase in MEP after anesthesia with both the inhalationa l anesthetics, but the increase in MEP was signifi cantly lower during isofl urane anesthesia, which makes it more suitable during middle ear surgery.