Effects of different depths of anesthesia with sevoflurane on cerebrovascular autoregulation in infants / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the effects of different depths of anesthesia with sevoflurane on cerebrovascular autoregulation in infants.Methods Twenty pediatric patients,of ASA physical status Ⅰ,aged 1-3 yr,undergoing elective hypospadias plasty surgery,were enrolled in the study.Single tube laryngeal mask was inserted after anesthesia was induced with 6％ sevoflurane inhalation.Caudal block was performed with 1 ml/kg of 0.2％ ropivacaine.Anesthesia was maintained with sevoflurane inhalation.The end-tidal sevoflurane concentration was adjusted to 1.8％,2.5％,3.3％ and 4.0％,and each concentration was maintained at this level for 15 min.The cerebral blood flow was collected from the middle cerebral artery immediately before adjusting the next concentration to record the Doppler spectrum and transient hyperemic response ratio (THRR) was measured.Results THRR at different depths of anesthesia with sevoflurane was larger than 1.09,and was within the normal range.THRR was significantly lower when the end-tidal concentration was 2.5％,3.3％ and 4.0％ than that obtained when end-tidal concentration was 1.8％.No significantdifference was detected in THRR between 2.5％ and 3.3 ％.THRR was significantly lower when the end-tidal concentration was 4.0 ％ than that obtained when the end-tidal concentration was 2.5％ and 3.3％.Conclusion Although the inhibitory effect on cerebrovascular autoregulation provided by sevoflurane anesthesia provides no obvious clinical significance,it shows statistical significance in infants.