Minimum alveolar concentration of sevoflurane for endotracheal intubation without body movement in premature infants / 临床麻醉学杂志

ABSTRACT

Objective To determine the minimum alveolar concentration for endotracheal intu-bation (MACEI )of sevoflurane for curbing the responses to endotracheal intubation in 50% premature infants less than 37 weeks of corrected age.Methods Twenty-seven ASA Ⅰ or Ⅱ premature infants less than 37 weeks of corrected age were enrolled in this study.At first,the anesthesia induction was started by inhaling 6% sevoflurane.After the patient lost consciousness,the end tidal sevoflurane concentration (CET Sev)was adjusted to the target concentration and maintained stable for 1 5 min.En-dotracheal tube was then intubated.The up-and-down sequential method was used to calculate the MAC.The initial CET Sev was 3.0% and it was increased or decreased by 0.2% in the next patient ac-cording to the endotracheal intubation response.If the intubation response was positive,the CET Sev was increased;if the intubation response was negative,the CET Sev was decreased.The midpoint from negative response to positive response was set as a balance point and the mean value of the concentra-tions of sevoflurane at all the balance points were calculated as MACEI .Results The end tidal sevoflurane concentration for blunting the responses to endotracheal intubation in 50% premature in-fants was 2.55%±0.20%,and the MAC9 5 was 2.81% (95% confidence interval 2.67%-3.58%). Conclusion The MACEI of sevoflurane for curbing the responses to endotracheal intubation in 50%premature infants less than 37 weeks of corrected age is 2.55%,which is lower than that in the full-term children.