This Article Résumé de cet Article Full Text Full Text (PDF) Submit a scholarly reply Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Pancaro, C. Articles by Peduto, V. A. Search for Related Content PubMed PubMed Citation Articles by Pancaro, C. Articles by Peduto, V. A.

Apnea during induction of anesthesia with sevoflurane is related to its mode of administration

[L’apnée pendant l’induction de l’anesthésie avec du sévoflurane est reliée au mode d’administration]

Carlo Pancaro, MD^*, Simone Giovannoni, MD, Adelchi Toscano, MD and Vito Aldo Peduto, MD

^* From the Department of Anesthesiology and Perioperative Medicine, Brigham & Women’s Hospital, Harvard Medical School, Boston, Massachusetts, USA; and
the Department of Anesthesiology and Intensive Care, University of Perugia, Perugia Italy.

Address correspondence to: Dr. Carlo Pancaro, Department of Anesthesiology and Perioperative Medicine, Brigham and Women’s Hospital, Harvard Medical School, 75 Francis Street, 02115 Boston, MA, USA. E-mail: carlopancaro{at}hotmail.com

Purpose: The incidence and duration of apnea during sevoflurane anesthesia have not been fully characterized. We hypothesized that sevoflurane at slowly increasing concentrations reduces incidence and shortens the duration of apnea compared to administration of a highly concentrated anesthetic mixture.

Methods: 131 women were randomly assigned to receive 35% oxygen in air and sevoflurane at: incremental concentrations of 1%, from 1% to 8% (group 1–8%, n = 42); decremental-incremental concentrations of 2%, from 8% to 4% and then from 4% to 8% (group 8–4–8%, n = 36); or fixed concentrations of 8% for induction of anesthesia (group 8%, n = 53). A blinded investigator observed whether and for how long patients stopped breathing.

Results: All groups reached 2.5 minimum alveolar concentration of end-tidal sevoflurane. Although apnea was observed in all groups, it was more frequent in the 8% group than in 1 to 8% (68% vs 21%, P < 0.05) or 8 to 4 to 8% groups (68% vs 20%, P < 0.05). Duration of apnea was also more pronounced in the 8% group than in 1 to 8% and 8 to 4 to 8% groups ( 58 ± 25 s vs 32 ± 18 sec, P < 0.05 and vs 35 ± 16 sec, P < 0.05, respectively).

Conclusions: Sevoflurane induces apnea more frequently and for longer duration at a fixed high concentration compared to incremental or decremental-incremental concentrations. Decremental-incremental concentrations offer the additional advantage of a speed of induction similar to that elicited by the 8% concentration.