Behavioural effects of chronic exposure to subanesthetic concentrations of halothane, sevoflurane and desflurane in rats.

Background: A double-blind, randomized trial was conducted to determine the behavioural effects of chronic exposure to subanesthetic concentrations of halothane, sevoflurane and desflurane in rats.

Methods: Halothane, sevoflurane and desflurane group rats received 0.1%, 0.3%, and 0.6% concentrations in a flow rate of 3 L.min(-1) O(2) respectively. Control animals also received 3 L.min(-1) O(2) in another investigation room, which had the same properties as the study group rooms. Rats breathed inhaled agents or oxygen between 09:00-13:00 hr every day for 30 days. After 30 days of inhalation of subanesthetic doses of inhaled agents or oxygen, behavioural tests were applied.

Results: Tests of exploratory activity and curiosity (hole-board test), anxiety (elevated plus maze test) and learning and memory functions (multiple T maze test), demonstrated that chronic exposure to subanesthetic concentrations of all three anesthetics alters behavioural functions in rats. However, impairment of learning (P<0.05) and memory function (P<0.05) were greater in association with desflurane, in comparison to halothane and sevoflurane-treated rats.

Conclusion: Chronic exposure to subanesthetic concentrations of halothane, sevoflurane and desflurane is associated with behavioural change in rats. Of the three drugs, desflurane was associated with the lowest learning and memory function test scores.