Sevoflurane-induced reduction of hypoxic drive is sex-independent

Background: Although the mu-opioid agonist morphine affects ventilatory con trol in men and women in different ways, no data exist regarding the influe nce of sex on the ventilatory effects of inhalational anesthetics. The auth ors compared the effect of sevoflurane on the ventilatory response to isoca pnic hypoxia in healthy young men and women, Methods: Breath-to-breath ventilatory responses to hypoxic steps (number of hypoxic steps, four-six; duration, 3 min; end-tidal oxygen tension, simila r to 50 mmHg; end-tidal carbon dioxide tension clamped at similar to 4 mmHg above resting values) were assessed in nine men and nine women without and with low-dose sevoflurane (end-tidal concentration, 0.25%). The bispectral index of the electroencephalogram was measured concomitantly. Results: Sevoflurane reduced the hypoxic ventilatory sensitivity significan tly in both sexes (men: control, 0.62 +/- 0.17 rs. sevoflurane, 0.38 +/- 0. 191 . min(-1) . %(-1); women: control, 0.52 +/- 0.30 vs. seroflurane, 0.34 +/- 0.15 l . min(-1) . %(-1)). Sevoflurane-induced reductions of the hypoxi c responses were not different in the men and women. During sevoflurane inh alation, the bispectral index values decreased equally In men and women, Conclusion: In contrast to morphine, the Influence of a low dose of the inh alational anesthetic sevoflurane on the ventilatory response to hypoxia is independent of sex.