///2009 Abstract Details
2009 Abstract Details2018-05-01T17:45:11+00:00

EXIT-to-ECMO: The Critical Role of Maternal Anesthesia

Abstract Number: 188
Abstract Type: Case Report/Case Series

Nicole S Wilder M.D.1 ; George B Mychaliska M.D.2; S D Chiravuri M.D.3; Jean Kreutzman MSN, CPNP4; Jill M Mhyre M.D.5

Background: The ex utero intrapartum treatment-to-extracorporeal membrane oxygenation (EXIT-ECMO) procedure has been performed in fetuses with anticipated respiratory failure at birth. This procedure allows for ECMO cannulation during placental support and potentially avoids hypoxia, hemodynamic instability, and acidosis while allowing a smooth transition from the womb to ECMO.

Methods: A retrospective chart review was conducted on all EXIT-to-ECMO procedures at the University of Michigan since 2006 to identify successful maternal anesthetic strategies and document maternal-fetal outcomes.

Results: Eight women underwent the EXIT-to-ECMO procedure, with an average maternal age of 28 years (range, 20-35), and an average gestational age of 37 weeks (range, 34-38). All received sodium bicitra and underwent rapid sequence intubation. The indications were severe congenital diaphragmatic hernia (n=5), cardiac rhabdomyoma (n=1), giant congenital cystic adenomatoid malformation of the lung (n=1) and giant pulmonary sequestration (n=1). Fetal hemodynamics during uteroplacental bypass were monitored by continued fetal echocardiography and pulse oximetry. One fetus experienced severe bradycardia nine minutes after uterine incision, was delivered, and underwent successful resuscitation. For the remaining seven maternal-fetal dyads, the mean duration of uteroplacental bypass was 8328 minutes (range, 34-125). Sevoflurane (3-4%) and intrauterine infusion of warmed crystalloid (70-90 ml/hr) provided adequate uterine distension in seven patients, while one required a bolus dose of nitroglycerin (200 mcg IV). Maternal mean arterial pressure was maintained within 84-100% of baseline using left uterine displacement, intravenous fluid and bolus ephedrine (5-10mg) and/or phenylephrine (50-100 mcg). Three patients also required a phenylephrine infusion (5-80 mcg/min), with an additional dopamine infusion in one. Six fetuses failed a trial of ventilation and were cannulated for ECMO while on placental support. Two fetuses maintained oxygen saturation over 90% during this trial and were delivered; both required ECMO support within 8 hours. All eight neonates survived the procedure; one died in the neonatal period. In seven women, uterine tone was promptly re-established following uterine evacuation, reduction of sevoflurane (to 0.6-2%), and oxytocin administration. One patient required additional oxytocin and a single dose of methylergonovine during the uterine repair. The average maternal fluid administered was 52.1 L of crystalloid and blood loss was 1025167 mL. Mean maternal length of stay was 3.82.9 days. There were no maternal complications.

Conclusion: Maternal hemodynamic stability and uterine relaxation are critical for maintaining fetal stability for prolonged uteroplacental bypass. The EXIT-to-ECMO procedure appears efficacious for anticipated neonatal respiratory failure with low maternal risk.

SOAP 2009