Extracorporeal membrane oxygenation for refractory hypoxemia after liver transplantation in severe hepatopulmonary syndrome: a solution with pitfalls

ECMO in severe hypoxemia post liver transplant for hepatopulmonary syndrome

Hepatopulmonary syndrome (HPS) poses a significant challenge in liver transplant patients, affecting between 10% and 30% of candidates. Historically, HPS was considered a contraindication for liver transplantation due to its association with high mortality rates. However, recent studies have shown improvements in pulmonary function post-transplant, leading to the inclusion of these patients as candidates. Despite this progress, approximately one-fifth of liver transplant recipients develop severe postoperative hypoxia, further complicating their clinical course and contributing to increased mortality. The management of post-transplant HPS involves various strategies, including extracorporeal membrane oxygenation (ECMO), although its use remains infrequently reported. Theoretical models suggest that oxygenation typically improves within 10 days post-transplant, while resolution of HPS may take 6-12 months, making ECMO an attractive possibility as a bridge to recovery in this population. We present a case were ECMO was used in this context.

New therapeutic strategy with extracorporeal membrane oxygenation for refractory hepatopulmonary syndrome after liver transplant: A case report

BACKGROUND

Due to the lack of published literature about treatment of refractory hepatopulmonary syndrome (HPS) after liver transplant (LT), this case adds information and experience on this issue along with a treatment with positive outcomes. HPS is a complication of end-stage liver disease, with a 10%-30% incidence in cirrhotic patients. LT can reverse the physiopathology of this process and restore normal oxygenation. However, in some cases, refractory hypoxemia persists, and extracorporeal membrane oxygenation (ECMO) can be used as a rescue therapy with good results.

CASE SUMMARY

A 59-year-old patient with alcohol-related liver cirrhosis and portal hypertension was included in the LT waiting list for HPS. He had good liver function (Model for End-Stage Liver Disease score 12, Child-Pugh class B7). He had pulmonary fibrosis and a mild restrictive respiratory pattern with a basal oxygen saturation of 82%. The macroaggregated albumin test result was > 30. Spirometry demon strated a forced expiratory volume in one second (FEV1) of 78%, forced vital capacity (FVC) of 74%, FEV1/FVC ratio of 81%, diffusion capacity for carbon monoxide of 42%, and carbon monoxide transfer coefficient of 57%. He required domiciliary oxygen at 2 L/min (16 h/d). The patient was admitted to the intensive care unit (ICU) and extubated in the first 24 h, needing high-flow therapy and non-invasive ventilation and inhaled nitric oxide afterwards. Reintubation was needed after 72 h. Due to the non-response to supportive therapies, installation of ECMO was decided with progressive recovery after 9 d. Extubation was possible on the tenth day, maintaining a high-flow nasal cannula and de-escalating to conventional oxygen therapy after 48 h. He was discharged from ICU on postoperative day (POD) 20 with a 90%-92% oxygen saturation. Steroid recycling was needed twice for acute rejection. The patient was discharged from hospital on POD 27 with no symptoms, with an 89%-90% oxygen saturation.

CONCLUSION

Due to the favorable results observed, ECMO could become the central axis of treatment of HPS and refractory hypoxemia after LT.

[Hepatopulmonary syndrome]

The hepatopulmonary syndrome (HPS) is one of the lung diseases associated with cirrhosis and portal hypertension. It should be discussed for any dyspnea in cirrhotic patients. HPS is a pulmonary vascular disease characterized by intrapulmonary vascular dilatations (IPVD). The pathogenesis is complex and seems to rely on communications between the portal and pulmonary circulations. The diagnosis is based on a triad of liver disease and portal hypertension, evidence of IPVDs, and impaired gas exchange (alveolar-arterial oxygen difference [A-aO2]≥15mmHg). HPS impairs prognosis (23% survival at 5years) and patients' quality of life. Liver transplantation (LT) allows regression of IPDVD in almost 100% of cases, normalization of gas exchange and improves survival with a 5-year post-LT survival between 76 and 87%. It is the only curative treatment, indicated in patients with severe HPS, defined by an arterial partial pressure of oxygen (PaO2) below 60mmHg. When LT is not indicated or feasible, long-term oxygen therapy may be proposed as a palliative treatment. A better understanding of the pathophysiological mechanisms is needed to improve the therapeutic possibilities in a near future.

Preemptive Venoarterial Extracorporeal Membrane Oxygenation for Liver Transplantation-Judicious Candidate Selection

Portopulmonary hypertension is a relatively common pathologic condition in patients with end-stage liver disease. Traditionally, severe pulmonary hypertension is regarded as a contraindication to liver transplantation (LT) due to a high perioperative mortality rate. Recently, extracorporeal membrane oxygenation (ECMO) has been utilized for intraoperative management of LT. As venoarterial (VA) ECMO may benefit certain high-risk LT patients by reducing the ventricular workload by the equivalent of the programmed flow rate, its usage requires multidisciplinary planning with considerations of the associated complications. We highlighted two cases at our single-center institution as examples of high-risk pulmonary hypertension patients undergoing LT on planned VA ECMO. These patients both survived the intraoperative period; however, they had drastically different postoperative outcomes, generating discussions on the importance of judicious patient selection. Since ECMO has removed the barrier of intraoperative survivability, the patient selection process may need to put weight on the patient's potential for postoperative recovery and rehabilitation. Considerations on LT recipients undergoing preemptive ECMO need to expand from the ability of the patients to withstand the demands of the surgery during the immediate perioperative period to the long-term postoperative recovery course.

Planned Extracorporeal Life Support Employment during Liver Transplantation: The Potential of ECMO and CRRT as Preventive Therapies-Case Reports and Literature Review

Liver Transplantation (LT) has become the gold standard treatment for End-Stage Liver Disease (ESLD). One of the main strategies to manage life-threatening complications, such as cardio-respiratory failure, is Extracorporeal Membrane Oxygenation (ECMO) in the peri-transplantation period, with different configurations of the technique and in combination with other extracorporeal care devices such as Continuous Renal Replacement Therapy (CRRT). This retrospective study includes three clinical cases of planned ECMO support strategies in LT and evaluates their application compared with current literature exploring PubMed/Medline. The three LT supported with ECMO and CRRT were performed at IRCCS Polyclinic S. Orsola-Malpighi, Bologna. All three cases of patients with compromised organ function analysed produced positive outcomes. The planned use of ECMO and CRRT support in peri-transplantation has allowed the patients to overcome contraindications and successfully undergo LT. In recent years, only a few reports have documented successful LT outcomes performed with intraoperative ECMO in critically ESLD patients. However, the management of LT with ECMO and/or CRRT assistance is an emerging challenge, with the need for more published evidence on this topic to guide treatment choices in patients with severe, acute and reversible respiratory and cardiovascular failure after LT.

Applications and Outcomes of Extracorporeal Life Support Use in Adult Liver Transplantation: A Case Series and Review of Literature

The use of extracorporeal life support (ECLS) is increasingly reported in adult liver transplantation (LT). However, neither the role of ECLS in the perioperative setting for LT nor its outcomes has been well defined. We performed a retrospective chart review of all adult LT patients at our institution who received ECLS from 2004 to 2021. We also conducted a comprehensive literature search for adult LT cases that involved perioperative ECLS for respiratory or cardiac failure. Over the study period, 11 LT patients required ECLS at our institution, two for respiratory and nine for cardiac failure. Both patients with respiratory failure received ECLS as a bridge to LT and survived to discharge. Nine patients required ECLS for acute cardiac failure either intraoperatively or postoperatively, and two survived to discharge. In the literature, we identified 35 cases of respiratory failure in LT patients requiring perioperative ECLS. Applications included preoperative bridge to LT (n = 6) and postoperative rescue (n = 29), for which overall survival was 44%. We identified 31 cases of cardiac failure in LT patients requiring either ECLS or cardiopulmonary bypass for cardiac support or rescue for intraoperative or postoperative cardiac failure (n = 30). There is evidence for consideration of ECLS as a bridge to LT in patients with potentially reversible respiratory failure or as rescue therapy for respiratory failure in posttransplant patients. ECLS has a prohibitively high risk of futility in pretransplant patients with cardiac failure but may have a role in LT patients with a functioning graft and potentially reversible cardiac failure.

Severe hepatopulmonary syndrome with hypoxemia refractory to liver transplant: Recovery after 67 days of ECMO support

Hepatopulmonary syndrome (HPS) is a complication of end stage liver disease (ESLD) and is manifested by severe hypoxemia, which usually responds to liver transplantation (LT). As compared to patients undergoing LT for other etiologies, patients with HPS present an increased risk of postoperative morbidity and mortality. There is no effective treatment for patients whose hypoxemia does not respond to LT. This subset of patients is at a highly increased risk of death. There are very few reports on the use of extracorporeal membrane oxygenation (ECMO) in this setting with rapid response. However, there is no prior report of ECMO utilization for longer than 4 weeks. We present the case of a 17 year-old male patient who underwent LT for ESLD secondary to chronic portal vein thrombosis and HPS. He received a liver from a deceased donor and presented with severe HPS after LT, requiring ECMO support for 67 days. The patient was discharged home and is breathing in ambient air. He is currently asymptomatic and has a normal liver function.

The role of extracorporeal membrane oxygenation in adult liver transplant patients: A qualitative systematic review of literature

BACKGROUND

A paucity of evidence exists regarding risks and benefits of extracorporeal membrane oxygenation (ECMO) in adult liver transplantation.

METHODS

This was a systematic review conducted from January 1, 2000 to April 24, 2020 of adult liver transplant recipients (pre- or post-transplant) and donors who underwent Veno-arterial or Veno-venous ECMO cannulation. Death was the primary outcome, with graft function and complications as secondary outcomes.

RESULTS

Forty-one articles were identified that fit criteria. A total of 183 donors were placed on ECMO, with recipient complication profiles and mortality that mirrored rates from standard criteria donors. Sixty-one recipients were placed on ECMO intraoperatively or postoperatively. Most patients experienced at least one complication with infections as the most common cause and minimal complications specifically related to ECMO use. Multisystem organ failure (MSOF) and infections were more common among liver recipients who died compared to those who survived. Overall mortality at 90 days was 45.9%. Causes of death were most commonly MSOF and infections.

CONCLUSIONS

ECMO use in adult liver transplantation is a useful adjunct. Recipient morbidity and mortality from donors placed on ECMO parallel that of recipients from standard criteria donors, and morbidity and mortality of recipients placed on ECMO are similar to other ECMO populations.

Hepatopulmonary Syndrome and Portopulmonary Hypertension: Pulmonary Vascular Complications of Liver Disease

Pulmonary vascular disease is a frequent complication of chronic liver disease and portal hypertension, affecting up to 30% of patients. There are two distinct pulmonary vascular complications of liver disease: hepatopulmonary syndrome (HPS) and portopulmonary hypertension (POPH). HPS affects 25% of patients with chronic liver disease and is characterized by intrapulmonary vasodilatation and abnormal arterial oxygenation. HPS negatively impacts quality of life and is associated with a 2-fold increased risk of death compared to controls with liver disease without HPS. Angiogenesis, endothelin-1 mediated endothelial dysfunction, monocyte influx, and alveolar type 2 cell dysfunction seem to play important roles in disease pathogenesis but there are currently no effective medical therapies. Fortunately, HPS resolves following liver transplant (LT) with improvements in hypoxemia. POPH is a subtype of pulmonary arterial hypertension (PAH) characterized by an elevated mean pulmonary arterial pressure and pulmonary vascular resistance in the setting of normal left-sided filling pressures. POPH affects 5% to 6% of patients with chronic liver disease. Although the pathogenesis has not been fully elucidated, endothelial dysfunction, inflammation, and estrogen signaling have been identified as key pathways involved in disease pathogenesis. POPH is typically treated with PAH targeted therapy and may also improve with liver transplantation in selected patients. This article highlights what is currently known regarding the diagnosis, management, pathobiology, and outcomes of HPS and POPH. Ongoing research is needed to improve understanding of the pathophysiology and outcomes of these distinct and often misunderstood pulmonary vascular complications of liver disease. © 2021 American Physiological Society. Compr Physiol 11:1-22, 2021.

Excellent outcomes with liver transplantation in hepatopulmonary syndrome across pre-transplant PaO2 spectrum

Background & Aims

Significantly worse survival has been reported in patients with hepatopulmonary syndrome (HPS) and partial pressure of arterial oxygen (PaO₂) <45 mmHg undergoing liver transplantation. Long-term pre- and post-transplant outcomes based on degree of hypoxaemia were re-examined.

Methods

A retrospective analysis of 1,152 HPS candidates listed with an approved HPS model for end-stage liver disease (MELD) exception was performed. A Fine and Gray competing risks model was utilised to evaluate pre-transplant outcomes for PaO₂ thresholds of <45, 45 to <60, and ≥60 mmHg. Post-transplant survival was analysed using the Kaplan-Meier method.

Results

Patients with a PaO₂ <45 mmHg were significantly more likely to undergo transplantation (hazard ratio [HR] 1.51; 95% CI 1.12-2.03), whereas patients with higher MELD scores had lower hazard of transplant (HR 0.80, 95% CI 0.67-0.95, p = 0.011) and higher hazard of pre-transplant death (HR 2.29, 95% CI 1.55-3.37, p <0.001). Post-transplantation, patients with a PaO₂ <45 mmHg had lower survival (p = 0.04) compared with patients with a PaO₂ ≥45 to <50 mmHg, with survival curves significantly different at 2.6 years (75% survival compared with 86%) and median survival of 11.5 and 14.1 years, respectively. Cardiac arrest was a more likely (p = 0.025) cause of death for these patients. Cardiac arrest incidence in patients who died with a PaO₂ >50 mmHg was 6.2%.

Conclusions

Patients with a PaO₂ <45 mmHg had a significantly higher rate of transplantation, and higher calculated MELD scores were associated with significantly higher pre-transplant mortality. Although post-transplant survival was lower in patients with a PaO₂ <45 mmHg, the median survival was 11.5 years, and survival curves only became significantly different at 2.6 years. This suggests that patients with HPS do benefit from transplantation up to 2-3 years post-transplant regardless of the severity of pre-transplant hypoxaemia.

Lay summary

A total of 1,152 patients with hepatopulmonary syndrome listed for liver transplant were analysed. Patients with a low PaO₂ <45 mmHg had a high likelihood of transplantation. If associated with advanced liver disease, the mortality risk was higher for patients with hepatopulmonary syndrome on the wait list. After liver transplantation, patients with a PaO₂ <45 mmHg had a lower survival, but this only became significant after 2.6 years, and the median survival was 11.5 years. This suggests that patients with hepatopulmonary syndrome do benefit from transplantation.

Outcomes of liver transplantation in patients with hepatopulmonary syndrome in the pre and post-MELD eras: A systematic review

BACKGROUND

The lack of large hepatopulmonary syndrome cohorts undergoing liver transplantation (LT) has resulted in limited information about post-LT outcomes and expectations.

METHODS

The long and short-term outcomes of LT in patients with hepatopulmonary syndrome (HPS) were evaluated before and after the implementation of Model for Endstage Liver Disease (MELD) score in 2002, granting exception points for patients with HPS. PubMed/Medline, Embase, Web of Science and Scopus databases were searched for published and unpublished studies from 01/1990 to 04/2019. Studies that included HPS patients who underwent LT and reported post-LT outcomes and HPS severity were reviewed. After reviewing the full text of 1421 articles, 30 were included in the pre-MELD era (before 2002) and 60 in the post-MELD era.

RESULTS

A total of 598 patients (210 children and 388 adults) with HPS who underwent LT were included in this systematic review. In children, 5-year survival probability was similar in the pre and post-MELD groups (85.7% vs. 97.4; p = 0.09). Median post-transplant PaO2 in room air was higher in the post-MELD group (71 [53-87] vs. 97 [80-108] mmHg: p = 0.008). In adults, 5-year survival probability was higher in the post-MELD era (73 vs. 87.3%; p = 0.008). Median post-transplant PaO2 in room air was higher in post-MELD group (75 [63-85] vs. 87 [75-95] mmHg; p = 0.001)..

CONCLUSIONS

After MELD exception implementation, survival rates and post-transplant oxygenation improved in adult patients with HPS who underwent liver transplantation, whereas only post-transplant oxygenation improved in children.

Outcome of extracorporeal membrane oxygenation support in patients with liver cirrhosis: a nationwide population-based cohort study

OBJECTIVES

Extracorporeal membrane oxygenation (ECMO) is used for life support in patients with liver cirrhosis (LC). However, there have been no studies evaluating the outcome of ECMO support in patients with LC.

METHODS

Using Taiwan's National Health Insurance (NHI) database, we retrospectively evaluated patients with LC who received veno-venous or veno-arterial ECMO between 1 January 2000 and 31 December 2013. The outcomes included ECMO-related complications, in-hospital mortality, all-cause mortality and long-term outcomes in patients with and without LC.

RESULTS

A total of 7003 patients who received ECMO, of whom 233 (3.3%) had LC, were eligible for analysis. The LC patients who received ECMO support had a significantly higher risk of in-hospital mortality than the non-LC group (76.4% vs 60.7%; odds ratio 1.97; 95% confidence interval 1.44-2.70). The LC group also had a higher risk of complications, including de novo dialysis and massive blood transfusion with >10 units of red blood cells. Patients ≥65 years of age, patients with respiratory disease, patients with hypoalbuminaemia and liver transplant patients had higher in-hospital and 1-year mortality. The mortality rates for patients with 2 or more risk factors were 90.3% and 95.8%, respectively. LC was associated with a higher incidence of all-cause mortality and liver-related outcomes during follow-up.

CONCLUSIONS

Our findings raise questions regarding the utility of ECMO for LC patients, especially when >2 risk factors have been identified. ECMO support for LC patients should be used with caution and with careful patient selection.

The evolving role of ECMO in liver transplantation

PURPOSE OF REVIEW

To review the indications for extra-corporeal membrane oxygenation (ECMO) in liver transplantation (LT) recipients and their optimal management on ECMO.

RECENT FINDINGS

Recent studies have reported a 30-40% survival rate among LT recipients that receive ECMO. Increasingly, case reports have documented successful outcomes of LT performed for patients on preoperative ECMO. Outcomes appear to be superior with patients in the immediate peri-LT period with reversible causes of severe, acute respiratory, and/or cardiovascular collapse. Mortality is most commonly secondary to infection. Volume optimization with CRRT may improve outcomes and perfusion to the graft, especially for patients on veno-arterial ECMO. There is little consensus on management of anticoagulation in these patients, but it can likely be held temporarily when the patient is coagulopathic and/or experiencing bleeding complications.

SUMMARY

ECMO should be considered in the peri-LT period for patients with severe, acute, and reversible causes of respiratory and/or cardiovascular collapse, with acceptable outcomes in patients that would otherwise not be expected to survive. Management of the post-LT patient on ECMO is challenging with a slowly enlarging body of literature to inform decision making.

Update on the management of acute liver failure

PURPOSE OF REVIEW

This review describes the current intensive care management of acute liver failure (ALF) and the latest evidence for emerging therapies.

RECENT FINDINGS

Mortality from ALF continues to improve and in some cases, medical therapy can negate the need for liver transplantation because of protocolized management in specialist centres. Liver transplantation remains the cornerstone of management for poor prognosis ALF. The reduced use of blood products in ALF reflects growing evidence of balanced haemostasis in severe liver disease. Prophylactic therapeutic hypothermia is no longer recommended for neuroprotection. In cases not suitable for liver transplantation, high-volume plasma exchange (HVP) has potential benefit, although further research on the optimal timing and dosing is needed. Although sepsis remains an important complication in ALF, the use of prophylactic antimicrobials is being questioned in the era of emerging bacterial resistance.

SUMMARY

ICU management of ALF has improved such that liver transplantation is not required in some cases. HVP has emerged as a potential therapy for patients who may not be good liver transplantation candidates. Nevertheless in suitable patients with poor prognosis liver transplantation remains the optimal therapy.

Hepatopulmonary syndrome after radiofrequency ablation of recurrent intrahepatic cholangiocarcinoma: a case report

Background

Radiofrequency ablation (RFA) is one of the definitive treatment modalities for liver cancer and has been increasingly used in the scenario of small-sized liver cancer. It is generally believed that RFA is minimally invasive and associated with a favorable safety profile in liver cancer patients. However, this interventional technique is subject to some morbidity in high-risk patients, such as those with complicating cirrhosis or a liver cancer located at a refractory segment.

Methods

Herein, we report the case of a middle-aged woman who developed acute liver failure with a complicating respiratory failure after RFA of recurrent intrahepatic cholangiocarcinoma.

Results

A diagnosis of hepatopulmonary syndrome was established. The patient was hospitalized in the intensive care unit for mechanical ventilation. Finally, the patient recovered from an eventful clinical course and survived free of recurrence until the last follow-up visit at 1 year after the discharge.

Conclusion

Our case report warns that hepatopulmonary syndrome, a less common morbidity secondary to liver cancer RFA, should require timely identification and appropriate management due to its life-threatening outcome.

Extracorporeal membrane oxygenation for post-transplant hypoxaemia following very severe hepatopulmonary syndrome

Hepatopulmonary syndrome (HPS) associated with end-stage liver disease has a high morbidity when room air PaO₂ is less than 50 mm Hg. Safe levels of oxygenation to facilitate transplantation have not been defined despite advancement in care. Postoperatively, hypoxaemia worsens due to ventilation perfusion mismatch contributed by postoperative pulmonary vasoconstriction and due to decrease in endogenous nitric oxide. A 16-year-old boy with cirrhosis presented with HPS and a PaO₂ of 37 mm Hg on room air and underwent living donor liver transplant. Although stable intraoperatively, he desaturated on the second postoperative day. Despite a number of interventions, oxygenation remained critically low on 100% inspired oxygen. Extracorporeal membrane oxygenator (ECMO) was established with instant improvement in oxygenation (PaO₂68 mm Hg), and the patient was eventually salvaged. We suggest that ECMO could be a means of managing refractory post-transplant hypoxaemia in patients with HPS.

Hepatopulmonary Syndrome and Portopulmonary Hypertension: Implications for Liver Transplantation

Hepatopulmonary syndrome (HPS) and portopulmonary hypertension (PoPH) represent serious pulmonary complications of advanced liver diseases. Orthotopic liver transplantation (OLT) is capable of completely resolving the underlying abnormalities associated with HPS. On the other hand, post-OLT response in patients with PoPH is less predictable, although heavily influenced by pre-OLT mean pulmonary arterial pressure. It remains the case that the opportunity to reverse 2 potentially fatal organ dysfunctions in the liver and the lung make HPS and PoPH more than worthy for further clinical investigations.

Noninfectious Pulmonary Complications of Liver, Heart, and Kidney Transplantation: An Update

Despite significant advances in surgical techniques, perioperative care, and immunosuppressive therapy, solid organ transplantation still carries considerable risk of complications. Pulmonary complications, in particular, are a major cause of morbidity and mortality. Although infectious complications prevail, the lungs are also vulnerable to a variety of noninfectious complications related to the transplant surgery and adverse effects of the immunosuppressive regimen. This article focuses on noninfectious pulmonary complications associated with the 3 most commonly performed solid organ transplant procedures: liver, kidney, and heart.

Extracorporeal membrane oxygenation support for refractory septic shock in liver transplantation recipients

Purpose

This study was designed to assess the outcome of the extracorporeal membrane oxygenation (ECMO) in liver transplantation (LT) recipients with refractory septic shock and predict the prognosis of those cases.

Methods

From February 2005 to October 2012, ECMO was used in 8 cases of refractory septic shock. Laboratory values including lactate and total bilirubin level just before starting ECMO were obtained and sepsis-related organ failure assessment (SOFA) score, acute physiology and chronic health evaluation (APACH) II score and simplified acute physiology score (SAPS) 3 were calculated. Subsequent peak serum lactate and total bilirubin level, and SOFA score after 24 hours of starting ECMO were measured.

Results

Comparisons were made between survivors and nonsurvivors. ECMO was weaned off successfully in 3 patients (37.5%) and 2 patients (25%) survived to hospital discharge. Clinical scores including SOFA, APACH II, and SAPS3 and laboratory results including lactate, total bilirubin and CRP were not significantly different between survivor and nonsurvivor groups. Lactate level and SOFA score tended to decrease after ECMO support in survivor group and total bilirubin and CRP level tended to increase in nonsurvivor group.

Conclusion

Our findings suggest that the implantation of ECMO might be considered in highly selected LT recipients with refractory septic shock.

EASL Clinical Practical Guidelines on the management of acute (fulminant) liver failure

The term acute liver failure (ALF) is frequently applied as a generic expression to describe patients presenting with or developing an acute episode of liver dysfunction. In the context of hepatological practice, however, ALF refers to a highly specific and rare syndrome, characterised by an acute abnormality of liver blood tests in an individual without underlying chronic liver disease. The disease process is associated with development of a coagulopathy of liver aetiology, and clinically apparent altered level of consciousness due to hepatic encephalopathy. Several important measures are immediately necessary when the patient presents for medical attention. These, as well as additional clinical procedures will be the subject of these clinical practice guidelines.

Massive pulmonary hemorrhage before living donor liver transplantation in infants

A massive pulmonary hemorrhage in patients with liver cirrhosis is a life-threatening complication that may result in a contraindication of a liver transplantation because of its high mortality rate. Herein, we present two infant biliary atresia cases that successfully underwent an LDLT that was followed by intensive respiratory care for the pretransplant massive pulmonary hemorrhage. Both cases exhibited severe respiratory failure (minimum PaO2/FiO2; 46 mmHg and 39 mmHg, respectively). To arrest the bleeding, we applied a very high positive pressure ventilation treatment (maximum PIP/PEEP; 38/14 cmH2O and 55/15 cmH2O, respectively), plasma exchange, several FFP transfusions, and recombinant factor VIIa via intrapulmonary administration. In addition, we used CHDF treatment, applied HFOV transiently, and treated the patient with inhalation of nitric oxide. Although we prepared ECMO for intra-operative use, both cases were successfully managed with conventional mechanical ventilation without using ECMO, which may have worsened the pulmonary hemorrhage due to the use of an anticoagulant. Use of an excessive positive pressure management, although it poses a risk for barotrauma, could be acceptable to arrest the pulmonary bleeding in selected cases of liver failure patients who have no time remaining before LDLT.

Proposed management algorithm for severe hypoxemia after liver transplantation in the hepatopulmonary syndrome

The hepatopulmonary syndrome (HPS) is defined as the triad of liver disease, intrapulmonary vascular dilatation, and abnormal gas exchange, and is found in 10-32% of patients with liver disease. Liver transplantation is the only known cure for HPS, but patients can develop severe posttransplant hypoxemia, defined as a need for 100% inspired oxygen to maintain a saturation of ≥85%. This complication is seen in 6-21% of patients and carries a 45% mortality. Its management requires the application of specific strategies targeting the underlying physiologic abnormalities in HPS, but awareness of these strategies and knowledge on their optimal use is limited. We reviewed existing literature to identify strategies that can be used for this complication, and developed a clinical management algorithm based on best evidence and expert opinion. Evidence was limited to case reports and case series, and we determined which treatments to include in the algorithm and their recommended sequence based on their relative likelihood of success, invasiveness, and risk. Recommended therapies include: Trendelenburg positioning, inhaled epoprostenol or nitric oxide, methylene blue, embolization of abnormal pulmonary vessels, and extracorporeal life support. Availability and use of this pragmatic algorithm may improve management of this complication, and will benefit from prospective validation.