Sevoflurane for patients with asthma.

Abstract

In their recent article, Habre et al. (1) found that asthmatic children tracheally intubated during sevoflurane anesthesia administration experienced a mean 17% increase in respiratory system resistance. They concluded that “one should be cautious when using sevoflurane for endotracheal intubation in asthmatic children.” We question whether this conclusion is warranted because 1) there is no control group, and 2) a 17% increase in resistance is minimal and unlikely to be of clinical consequence. Endotracheal intubation is a significant stimulus to airway constriction, especially in patients with hyperreactive airways. If Habre et al. had studied a control group whose tracheas had been intubated after thiopental, propofol, or even halothane induction of anesthesia, they might have found a much larger increase in resistance. In a group of asthmatics tracheally intubated after propofol induction, we found a mean increase in respiratory resistance of 300%–400% (2). Hence, an increase of only 17% after deep sevoflurane anesthesia administration leads us to conclude that sevoflurane is most likely an excellent anesthetic for the induction of an asthmatic patient. We also disagree with their statement that their study is at odds with our finding that 1.1 minimum alveolar concentration sevoflurane decreases resistance after intubation (3). We studied the ability of sevoflurane to decrease resistance after intubation under thiopental anesthesia. The study of Habre et al. examined the result of intubation under deep sevoflurane anesthesia, but did not compare it to any other anesthetic. Had they used a control group, they might have found that sevoflurane was an effective anesthetic in preventing a large increase in resistance—a result that would be in line with our findings. Michael J. Bishop MD G. Alec Rooke MD, PhD