Prospective evaluation of outcomes and predictors of mortality in patients with hepatopulmonary syndrome undergoing liver transplantation

Abstract

The hepatopulmonary syndrome (HPS) occurs in a subgroup of patients with cirrhosis and results from intrapulmonary vasodilatation, which may cause significant hypoxemia. Liver transplantation has emerged as a therapeutic option for patients with HPS based on retrospective case series and reports. However, morbidity and mortality appear to be increased after transplantation for HPS, and no prospective studies evaluating clinical features that may predict poor surgical outcome are available. Therefore, we prospectively evaluated the utility of the degree of hypoxemia, the arterial oxygen response to 100% oxygen administration, and the macroaggregated albumin (MAA) scan quantification of intrapulmonary shunting as predictors for outcome after liver transplantation. Our cohort consisted of 24 patients with cirrhosis and HPS who underwent liver transplantation over a 5-year period at 2 transplant centers who were followed at least 1 year after transplantation. All patients underwent preoperative evaluation for HPS with standardized methods. Seven patients (29%) died postoperatively, 5 of cardiorespiratory complications. All deaths occurred within 10 weeks after transplantation. A preoperative arterial oxygen tension (PaO 2 ) of < 50 mm Hg alone or in combination with a MAA shunt fraction > 20% were the strongest predictors of postoperative mortality. In conclusion, we found that mortality is increased after liver transplantation for HPS, particularly in patients with more severe hypoxemia and significant intrapulmonary shunting. Preoperative testing for the severity of HPS can be used to stratify patients according to the risk for postoperative mortality. (HEPATOLOGY 2003;37:192-197.)

Natural history of hepatopulmonary syndrome: Impact of liver transplantation

“…There are 2 reasonable arguments and supporting data to suggest HPS should advance the priority to accomplish OLT, assuming comorbidity is minimal. First, HPS has been shown to have an independent adverse effect on mortality before liver transplantation, 11 and second, complete resolution of HPS frequently occurs in patients surviving the transplant hospitalization. 1,5,6 If the patient survives the immediate postoperative course (intensive care unit/ transplant hospitalization), there is a high likelihood of normalization of arterial oxygenation over time (many months) with little chance of recurrence of HPS.…”

Clinical implications of the hyperdynamic syndrome in cirrhosis

“…HPS is defined as the presence of liver disease and/or PH and intrapulmonary vascular dilatation, resulting in an abnormal age-corrected alveolar-arterial oxygen gradient (partial pressure of oxygen [PaO2] of b80 mmHg, and an AaPO2 of N15 mmHg, or N20 mmHg in patients N64 years of age) [58]. A taxonomy of the severity of the HPS based on alterations in oxygenation is essential because severity influences survival and is useful in determining the timing and the risks of orthotopic liver transplantation (OLT) [59,60]. The pulmonary gas exchange abnormalities of HPS are characterized by hyperventilation and arterial deoxygenation that can be mild (PaO2 b 80 mmHg), moderate (PaO2 b70 mmHg), or severe (PaO2 b 60 mmHg) [58].…”

Proposed Management Algorithm for Severe Hypoxemia After Liver Transplantation in the Hepatopulmonary Syndrome

“…Although select, highly specialized centers have demonstrated good posttransplant outcomes in very severely hypoxemic patients with HPS 9, 52, in addition to the increased risk of posttransplant hypoxemia 10, studies have demonstrated increased overall posttransplant mortality in patients with a pretransplant PaO 2 ≤50 mmHg 7, 11, 53. These data, along with the expected decline in PaO 2 of 5.2–13.5 mmHg per year in patients with HPS 7, 9 coupled with expected delays to transplantation, form the basis for the UNOS MELD exception threshold of PaO 2 <60 mmHg in HPS.…”

“…Although liver transplantation (LT) is curative in HPS, these patients have an elevated postoperative complication rate 6, 7, 8, 9. In particular, “severe posttransplant hypoxemia,” defined as a need for 100% inspired oxygen (FiO 2 ) to maintain a saturation of ≥85% (out of proportion to any other concurrent lung process) 10, has been identified as a major complication leading to prolonged ICU stay and death in this population 6, 9, 10, 11, 12. Although survivors have a complete normalization of gas exchange over time, severe posttransplant hypoxemia occurs in 6–21% of HPS patients, carries a mortality of 45%, and accounts for the majority of peri‐operative deaths in this population 10.…”