(888) High-Flow Oxygen and Nitric Oxide in Pediatric Hepatopulmonary Syndrome After Liver Transplant

Introduction: Post-operative management of hepatopulmonary syndrome (HPS) following liver transplant in pediatric patients can be tenuous, and prolonged intubation and extracorporeal membrane oxygenation (ECMO) in the post-transplant period are associated with many risks. There are case reports in the literature employing non-invasive ventilation (NIV) or high flow nasal cannula (HFNC) for post-transplant hypoxemia associated with HPS. HFNC treatment has also been used in conjunction with inhaled nitric oxide (iNO) as a pulmonary vasodilator to support V-Q matching in areas unaffected by HPS to mitigate hypoxic vasoconstriction.

Description: A 14 year-old girl with end stage liver disease secondary to congenital biliary atresia and HPS presented for orthotopic liver transplant (OLT). Pre-transplant she required 5-6 liters (L) low flow nasal cannula (LFNC) at 100% fraction of inspired oxygen (FiO2) with pre-transplant partial pressure of arterial oxygen (PaO2) of 77 mmHg with a lactate of 1.0, reflecting severe hypoxemia and severity of HPS. A cadaveric orthotopic liver allotransplant and roux-n-y hepaticojejunostomy were performed without complication. She returned to the pediatric intensive care unit (PICU) intubated on FiO2 60% with goal SpO2 >85%. Immediate post-op PaO2 was 73 mmHg with a lactate of 4.5 in the OR. Initial PaO2 in the PICU decreased to 58 mmHg, thought to be exacerbated by post-op atelectasis and pulmonary edema, however lactate improved to 1.6. She was extubated post-operative day (POD) 1 to HFNC 15L 100% FiO2 with subsequent PaO2 81 mmHg with a lactate of 2.1. She received iNO up to 50ppm POD 3- POD 7 to maintain SpO2 >85%. Maximum HFNC support was 35L with 100% FiO2. Flat/Trendelenburg positioning was also used to support respiratory status. She was ultimately weaned to LFNC on POD 10, transferred to the floor on POD 14 on 3L LFNC, and ultimately discharged home 18 days after OLT on 1.5-2L LFNC.

Discussion: We present a case of successful management of post-transplant HPS using HFNC, iNO, and Trendelenburg positioning, avoiding the need for prolonged intubation and ECMO in the post-transplant period. Using early transition to HFNC to support oxygenation not only reduces risks but also may encourage early mobilization, decreased sedation, and shorter hospital stays.