GA1-49
ECMO after liver transplantation in pediatric patient with severe hepatopulmonary syndrome
Lippert B, Wilder M, Wachs M
Children's Hospital Colorado, Aurora, CO, United states
Hepatopulmonary syndrome (HPS) is a severe but common disease characterized by decreased arterial oxygenation, intrapulmonary vascular dilations (IPVD) and hepatic disease. Understanding of HPS is limited and there is no effective medical treatment available. Liver transplantation (LT) is the only therapy capable of reversing HPS and improving survival rates. In this case, we present a pediatric patient with very severe HPS whose post-LT course was complicated by progressive hypoxemia, requiring extracorporeal membrane oxygenation (ECMO). To our knowledge, this is only the second case report of a pediatric patient with HPS requiring ECMO after liver transplantation.
Our patient is a 13-year-old male with idiopathic non-cirrhotic hepatoportal sclerosis and HPS. He presented with platypnea, cyanosis and orthodeoxia. His PaO2 on room air was 37 mmHg, with an alveolar-arterial gradient of 65. At rest he required 15 L/min O2 with intermittent need for BiPAP. Cardiac catheterization revealed arterial-venous malformations resulting in severe intrapulmonary shunting. He subsequently underwent an uneventful LT. In the ICU he experienced progressive hypoxemia, complicated by bilateral pneumothoraces and multiple reintubations. Interventions included aggressive pulmonary toilet, chemical paralysis, proning, inhaled nitric oxide, and a sildenafil infusion, all resulting in minimal improvements in oxygenation. One month after OLT, he was placed on veno-venous ECMO, which he still requires two months later.
HPS is a common, yet severe pulmonary vascular complication of liver disease. LT is the only effective therapy for reversal of HPS. As a perioperative clinician, it is vital to understand the diagnosis, staging and prognosis of HPS, as well as the treatment options available for HPS-related hypoxemia following LT.
HPS can present with progressive dyspnea, cyanosis, fatigue, orthodeoxia, platypnea and spider nevi [1]. The diagnostic triad includes liver disease, an elevated A-a gradient on room air (>15 mmHg) and IPVD. Microbubble transthoracic echocardiography (MTTE) is the diagnostic gold standard. For prognosis and the timing of LT, HPS is classified by stage: mild (PaO2 ≥ 80 mmHg), moderate (PaO2 60 to < 80 mmHg), severe (PaO2 50 to < 60 mmHg), and very severe (PaO2 < 50 mmHg) [1]. Patients with severe HPS have an increased risk of death after LT. Three year post-LT survival is 84% for patients with PaO2 of 44.1-54.0 mmHg vs 68% for those with PaO2 ≤ 44.0 mmHg [2].
Reversal of HPS after LT usually occurs within one year [3]. Treatment of hypoxemia in these post-LT patients before HPS resolution is difficult, and recommendations are derived from case reports and expert opinion. Treatment algorithms have been proposed, which focus on decreasing right-to-left shunting via IPVD and include: Trendelenburg position, phosphodiesterase inhibitors, inhaled vasodilators, methylene blue, embolization of IPVD, and ultimately ECMO [4]. More prospective studies are needed to optimize treatment strategies.
1. RodrÃguez R et al. Eur Respir J. 2004;24:861–880.
2. Goldberg DS et al. Gastroenterol. 2014 May;146(5):1256-65
3. Pascasio JM et al. Am J Transplant. 2014;14:1391–1399.
4. Nayyar D et al. Am J Transplant. 2015 April;15(4):903-13.
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