29: Use of Extracorporeal Membrane Oxygenation (ECMO) to Manage Severe Life-threatening Postpartum Hypoxia Associated with Agenesis of the Right Pulmonary Artery

Introduction. Pregnancy induces physiological changes, including alterations in respiratory and cardiovascular systems, which can unmask underlying congenital conditions. The increased use of extracorporeal membrane oxygenation (ECMO) in obstetric patients improved outcomes significantly in the last decades. Methods. A 33-year-old-female, with a history of gestational diabetes mellitus, underwent an uneventful elective caesarean section under spinal anaesthesia. In the 24 hours postoperatively, she developed severe hypoxemia. Chest radiographs showed progressively worsening left lung pathology resulting in a complete whiteout, with an apparent sparing of the right lung. A pulmonary angiogram CT was taken revealing agenesis of the right pulmonary artery, hypoplastic right lung, mediastinal shift, with no evidence of pulmonary embolism and multifocal central ground-glass opacification in the left lung, likely due to pulmonary oedema or acute haemorrhage. As hypoxia worsened despite high-flow oxygen, the patient was admitted to the intensive care unit and subsequently intubated without any improvement in gas exchange and with high respiratory pressures. Emergency V-V ECMO was instituted due to refractory life-threatening hypoxia. Pulmonary haemorrhage, acute pulmonary oedema and amniotic fluid embolism were potential diagnoses. Results. The patient was extubated and decannulated within 4 days. Despite the severity of her condition, she recovered and was discharged 7 days after decannulation. No long-term pulmonary complications were noted at follow-up. It is postulated that the agenesis of the right pulmonary artery, with the burden of pregnancy, alongside undiagnosed pre-eclampsia, caused the acute rise of pressures in the single left pulmonary artery, resulting in acute pulmonary oedema and refractory hypoxia. Amniotic fluid embolism may have contributed, but cannot be proven nor fully clinically attributable, due to the atypical characteristics of the case. Conclusion: ECMO can be safely utilized in peripartum settings. Multidisciplinary decision making with prompt institution of advanced critical care interventions, including ECMO, resulted in a positive outcome and should be considered in similar cases.