Ex utero intrapartum surgery (EXIT): Combined spinal epidural anesthesia (CSE) and general anesthesia with remifentanil. Case Report

Congenital  high  airway obstruction  syndrome (CHAOS)  is  a life-threatening condition with  a  poorly  understood natural history[1].   EXIT  is a controlled technique that  is designed to allow partial  fetal  delivery  via cesarean section  with subsequent establishment  of  a safe  fetal airway,  requires maintenance  of  uterine relaxation  to continue  placental  perfusion and  prevent placental separation[2]. A healthy 28 year old primigravida,   33  weeks  of  gestation,   with  a fetus known  to have  CHAOS due  to tracheal atresia and  ascites,   scheduled  for EXIT. Phase  1: ascites drainage by punction and  fetus external  version (breech presentation) before EXIT.  CSE  was chosen  for this  phase  (5mg  hyperbaric bupivacaine and 25ug fentanyl,   intrathecally),   with  light  conscious sedation  (midazolan  5mg).  Epidural catheter  was placed. Phase 2: Fetus had a  tracheal atresia.  Laryngotracheoplasty was  needed. Based on  estimated fetal weight, an  intramuscular injection  of  fentanyl 10ug/kg,   vecuronium  0.2mg/kg  and atropine  10ug/kg  was given to  the fetus[3]. After propofol induction,  sevoflurane (2  MAC)  and intravenous  nitroglycerin,  to ensure a  fully  relaxed uterus,  and remifentanyl  infusion  (cardiovascular stability),  was given to the mother. Fetopalcental support  last  for 20  min,   fetus laryngotracheoplasty was done. Apgar was 3/4. CSE should  be considered for EXIT.  Nitroglycerin  infusion  along with  deep volatile anesthesia  provides full uterine relaxation preventing  placental separation  while preserving placental  perfusion.  Remifentanyl  should be considered in high-risk obstetric surgery[4].