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Pulmonary hypertension: Hemodynamic assessment and response to vasodilators
Published in Debabrata Mukherjee, Eric R. Bates, Marco Roffi, Richard A. Lange, David J. Moliterno, Nadia M. Whitehead, Cardiovascular Catheterization and Intervention, 2017
Myung H. Park, Vallerie V. Mclaughlin
PAH associated with CHD occurs as a result of high pulmonary blood flow from systemic-to-pulmonary shunts and from smaller lesions such as atrial septal defect. Portopulmonary hypertension is PAH that occurs in asso- ciation with liver disease and portal hypertension and is reported in 4%-15% of patients being evaluated for liver transplantation.100, 101 Portal hypertension results in a high CO state, so in general, the COs of portopulmonary hyper- tension patients tend to be higher than other types of PAH. A normal CO in a portopulmonary hypertension patient suggests RV dysfunction. Mean PAP >35 mmHg has sig- nificant impact on peritransplant morbidity and survival.102 Regarding toxic agents, a definite association between ingestion of amphetamine-derived drugs and PAH has been established, the most notable ones being appetite suppres- sants aminorex, fenfluramine, and dexfenfluramine.24 All of these agents have been removed from the market after studies demonstrated linkage between these drugs and PAH. An association between methamphetamine use and PAH has been reported recently as well.8, 103 HIV infection is a risk for PAH with approximately 1 of 200 patients being affected.104 Among patients with PAH, survival is the worst for patients with CTD and HIV.61
Complications of Liver Transplantation
Published in Stephen M. Cohn, Matthew O. Dolich, Complications in Surgery and Trauma, 2014
David M. Levi, Gennaro Selvaggi, Andreas G. Tzakis
Acute respiratory distress syndrome (ARDS) that develops after liver transplantation is usually triggered by sepsis. It develops in 5%–17% of posttrans-plant patients and is associated with intra-abdominal infections, acute cellular rejection (ACR), pancreatitis, and hepatic artery thrombosis (HAT) with resulting hepatic necrosis [5]. It is diagnosed by excluding other etiologies of respiratory failure, primarily pneumonia. Portopulmonary hypertension is present in 2%–4% of patients with end-stage liver disease, and it remains a contraindication to liver transplant [6]. The pathophysiology of the disease is not clear, but it is related to portal hypertension. In patients with severely elevated pulmonary pressures and increased pulmonary vascular resistance, implantation and reperfusion of the liver during the transplant procedure results in acute right heart failure and is usually fatal. Careful screening for portopulmonary hypertension is a routine part of the pretransplant evaluation. An elevated estimated systolic pulmonary artery (PA) pressure determined by transthoracic echocardiography is confirmed by direct measurement with right heart catheterization. A mean PA pressure of >35 mmHg and/or a PA systolic pressure of >50 mmHg in the absence of volume overload (normal pulmonary capillary wedge pressure) mandates treatment and correction prior to transplant. Medical therapy has improved with the advent of potent vasodilatory agents [7,8]. Some patients are successfully treated and can undergo liver transplant.
Diagnosis and treatment of pediatric pulmonary arterial hypertension
Published in Expert Review of Cardiovascular Therapy, 2019
Nesrine Farhat, Frederic Lador, Maurice Beghetti
The most frequent infectious agents associated with PAH are HIV and schistosomiasis [6]. Schistosomiasis is today potentially the most prevalent cause of PAH worldwide, endemic in Africa, Southeast Asia, China, and some parts of Brazil. Approximately 5% of the patients with hepatosplenic schistosomiasis may develop PAH [6,8]. The pathogenesis of HIV-related PAH remains unclear suggests that an indirect action of viral infection on inflammation and growth factors may act as a trigger in a predisposed patient. A screening for PAH in asymptomatic HIV-patients is not recommended [10]. Very few patients are reported with these etiologies in pediatric registries so far. Portopulmonary hypertension occurred in 2% to 6% of the patients with portal hypertension, with a risk of developing PAH independent of the severity of the liver disease [8]. Reports in children are scarce but this may be due to underdiagnosis.
Pulmonary hypertension in patients with a history of intravenous drug use
Published in Current Medical Research and Opinion, 2019
Michael McGee, Nicholas Whitehead, Scott Twaddell, Nicholas Collins
Progressive advances in the treatment of hepatitis C viral infection, including those with advanced disease including cirrhosis, have demonstrated stabilization and potential improvement in terms of the development of cirrhosis, reflecting the remarkable regenerative ability of the liver. Combination antiviral therapies, both with and without interferon therapy, that target specific hepatitis C proteins, can potentially result in reversal of cirrhosis. The potential for these treatments in portopulmonary hypertension has not yet been explored.
Rapid resolution of refractory hypoxemia and vascular spiders following liver transplantation
Published in Canadian Journal of Respiratory, Critical Care, and Sleep Medicine, 2022
Allison Love, Rachel Jen, Lindsay Van Tongeren, C. Francis Ryan
The severity of hypoxemia in HPS can range from subclinical to severe and life threatening. Milder cases are common and can be managed by observation and periodic reassessment for worsening hypoxemia.7 Several experimental approaches using vasoactive agents have been proposed, but none has been shown in good quality studies to be consistently effective.15 Rarely, embolization of IPVDs has been undertaken. HPS in chronic liver disease is associated with poor quality of life and reduced survival.3 Liver transplantation, for which HPS is now an important indication, remains the only definitive treatment, and is reserved for patients with severe and very severe disease.7 Severe pre-transplant hypoxemia was previously believed to portend a worse prognosis post-transplant. However, recent data indicate better outcomes, particularly in patients with milder liver disease who might not have previously qualified for liver transplantation based on standard severity indices. As in our case, these patients require the application of a standard MELD exception score to qualify for liver transplantation.16 Under these circumstances, the severity of pre-transplant hypoxemia does not appear to affect post-transplant survival.17 Our patient had no evidence of portopulmonary hypertension, the other well recognized pulmonary vascular complication of liver disease. Cases of coexisting HPS and portopulmonary hypertension have been reported, as have cases of portopulmonary hypertension developing after liver transplantation for HPS. Hepatopulmonary syndrome rarely recurs after liver transplantation. Retrospective case series have reported improvements in oxygenation post liver transplantation, with complete reversibility in 52% to 100% of patients within 6-12 months.18 Improvements in the partial pressure of arterial oxygen and A-a gradient for oxygen occur more quickly than reduction in intrapulmonary shunting, as demonstrated by contrast echocardiography. Dramatic improvement in oxygenation within one week of liver transplant, such as occurred in our patient, has been reported but is exceptional.