[Anesthetic management of the ex-utero intrapartum treatment (EXIT) procedure for congenital high airway obstruction syndrome (CHAOS)].

We report an experience of anesthetic management of the ex-utero intrapartum treatment (EXIT) procedure performed in a fetus with congenital high airway obstruction syndrome (CHAOS) due to laryngeal atresia at 30 weeks' gestation. Anesthesia of the mother was induced with rapid sequence, and maintained with 3.5% sevoflurane in 100% oxygen and fentanyl before delivery. Two minimum alveolar concentration (MAC) sevoflurane provided excellent uterine relaxation without maternal hypotension. After hysterotomy, a sterile pulse oxymeter was placed on the fetus hand for monitoring fetal SpO2 and pulse rate, and a Doppler ultrasound transducer was applied to monitor fetal heart rate. Fentanyl (5 microg x dl(-1)) and pancuronium (0.2 mg x dl(-1)) were injected into the fetal upper arm in addition to transplacental anesthetic agents. The fetal heart rate and SpO2 were stable throughout the fetal manipulations, but the rise in SpO2 after initiating ventilation via tracheostomy was very slow. The uterine tone improved soon after discontinuing sevoflurane and oxytocin infusion was started after delivery. Surfactant administration before first ventilation is recommended in preterm babies undergoing EXIT procedure, and capnometer may be useful to confirm the adequate ventilation before cutting the umbilical cord.