Managing Refractory Hypoxia Due to Hepatopulmonary Syndrome Post-Liver Transplant with High-Dose Garlic: A Case of Improved Oxygenation

Document Type

Conference Proceeding

Publication Date

5-15-2026

Publication Title

Am J Respir Crit Care Med

Keywords

General & Internal Medicine, Respiratory System

Abstract

Hepatopulmonary syndrome (HPS), present in up to one-third of patients with advanced liver disease, is characterized by liver dysfunction, intrapulmonary vascular dilatation, and impaired gas exchange. Liver transplantation is the only definitive cure; however, persistent post-transplant hypoxemia may occur, often requiring 100% supplemental oxygen. We describe the management of a patient with refractory hypoxia after liver transplantation and the novel therapeutic measures employed. Case Presentation: A patient with decompensated cirrhosis secondary to alcohol use developed severe hypoxia, with home oxygen saturations of 80-90% on 3-6 L/min oxygen, minimal dyspnea, a positive late bubble study suggestive of intrapulmonary shunting, and normal pulmonary artery pressures—consistent with HPS. Following liver transplantation, his course was complicated by refractory hypoxia, with oxygen saturations on 6 L/min fluctuating between 80-90% supine and 70-80% upright. Workup including echocardiogram, contrast CT, and pulmonary angiogram with pressure measurements ruled out pulmonary embolism, arteriovenous malformations, and parenchymal lung disease. His condition was attributed to worsening post-transplant HPS. With escalating oxygen needs and desaturations to 30-40% on minimal exertion, he required heated high-flow nasal cannula support. A multidisciplinary team administered 100 mg of methylene blue, resulting in partial improvement. High-dose garlic therapy (4 g daily) was subsequently initiated, and within one week he was discharged on 10-15 L/min oxygen. Over three months, his oxygenation and dyspnea improved steadily, culminating in complete resolution of hypoxemia, at which point garlic was discontinued. Discussion: In decompensated cirrhosis, elevated nitric oxide (NO) levels drive pulmonary vasodilatation, promoting HPS. After transplantation, NO levels decline, but vascular remodeling lags, causing preferential perfusion through persistently dilated vessels and ventilation-perfusion mismatch. Although gradual post-transplant improvement is reported, evidence for effective interventions in adults remains limited. Vasodilators were avoided to prevent worsening orthodeoxia; extracorporeal membrane oxygenation was deferred given uncertain recovery timing. Methylene blue, a NO scavenger and guanylate cyclase inhibitor, has demonstrated transient improvement in oxygenation in HPS. High-dose garlic has shown benefit via modulation of NO and endothelin-1 pathways, with longer-lasting effects. The transient methylene blue response supported subsequent garlic therapy, ultimately leading to complete resolution of severe hypoxemia. Conclusions This case highlights potential utility of methylene blue and high-dose garlic supplementation in refractory post-transplant hypoxemia due to HPS. Further research should clarify mechanisms, identify responders, and guide targeted therapy to improve outcomes in this high-risk population.

Volume

212

Issue

Supplement_1

First Page

2

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