Perioperative Care of the Liver Transplant Patient

Thrombotic complications post liver transplantation: Etiology and management

Liver transplantation (LT) is the life saving therapeutic option for patients with acute and chronic end stage liver disease. This is a routine procedure with excellent outcomes in terms of patient survival and quality of life post LT. Orthotopic LT (OLT) patients require a critical care as they are prone to variety of post-operative vascular, cardiovascular, biliary, pulmonary and abdominal complications. Thrombotic complications (both arterial and venous) are not uncommon post liver transplant surgery. Such vascular problems lead to increased morbidity and mortality in both donor and graft recipient. Although thromboprophylaxis is recommended in general surgery patients, no such standards exist for liver transplant patients. Drastic advancements of surgical and anesthetic procedures have improvised survival rates of patients post OLT. Despite these, haemostatic imbalance leading to thrombotic events post OLT cause significant graft loss and morbidity and even lead to patient's death. Thus it is extremely important to understand pathophysiology of thrombosis in LT patients and shorten the timing of its diagnosis to avoid morbidity and mortality in both donor and graft recipient. Present review summarizes the current knowledge of vascular complications associated with LT to highlight their impact on short and long-term morbidity and mortality post LT. Also, present report discusses the lacunae existing in the literature regarding the risk factors leading to arterial and venous thrombosis in LT patients.

Related factors associated with the prognosis of children undergoing liver transplantation under the enhanced recovery after surgery nursing concept

This study aimed to investigate factors associated with the clinical outcomes of patients who underwent pediatric liver transplantation (LT) and received enhanced recovery after surgery (ERAS) nursing. A cohort of 104 pediatric patients was studied at our hospital. Data on 8 indicators and 2 clinical outcomes, including length of hospital stay (LOS) and 30-day readmission rates, were collected. Linear and logistic regression analyses were employed to examine the associations of the 8 indicators with hospital-LOS and readmission risks, respectively. The predictive value of these indicators for the outcomes was determined using the receiver operating characteristic (ROC) curve, decision curve analysis, and importance ranking through the XGBoost method. A comprehensive model was developed to evaluate its predictive accuracy. Regression analyses identified donor age, donor gender, and intensive care unit (ICU)-LOS of recipients as significant predictors of hospital LOS (all P < .05), whereas no indicators were significantly associated with readmission risk. Further, ROC analysis revealed that 3 indicators provided superior prediction for 28-day hospital LOS compared to the median LOS of 18 days. ICU-LOS demonstrated the highest clinical net benefit for predicting 28-day hospital-LOS. Multivariable regression analysis confirmed the independent predictive value of donor age and ICU-LOS for the hospital-LOS (all β > 0, all P < .05). Although the comprehensive model incorporating donor age and ICU-LOS showed stable predictive capability for hospital-LOS, its performance did not significantly exceed that of the individual indicators. In pediatric LT, hospital LOS warrants greater emphasis over readmission rates. Donor age and ICU-LOS emerged as independent risk factors associated with prolonged hospital LOS.

Primary Nonfunction of the Liver Allograft

Severe allograft dysfunction, as opposed to the expected immediate function, following liver transplantation is a major complication, and the clinical manifestations of such that lead to either immediate retransplant or death are the catastrophic end of the spectrum. Primary nonfunction (PNF) has declined in incidence over the years, yet the impact on patient and healthcare teams, and the burden on the organ pool in case of the need for retransplant should not be underestimated. There is no universal test to define the diagnosis of PNF, and current criteria are based on various biochemical parameters surrogate of liver function; moreover, a disparity remains within different healthcare systems on selecting candidates eligible for urgent retransplantation. The impact on PNF from traditionally accepted risk factors has changed somewhat, mainly driven by the rising demand for organs, combined with the concerted approach by clinicians on the in-depth understanding of PNF, optimal graft recipient selection, mitigation of the clinical environment in which a marginal graft is reperfused, and postoperative management. Regardless of the mode, available data suggest machine perfusion strategies help reduce the incidence further but do not completely avert the risk of PNF. The mainstay of management relies on identifying severe allograft dysfunction at a very early stage and aggressive management, while excluding other identifiable causes that mimic severe organ dysfunction. This approach may help salvage some grafts by preventing total graft failure and also maintaining a patient in an optimal physiological state if retransplantation is considered the ultimate patient salvage strategy.

Enhanced recovery after surgery programs improve short-term outcomes after liver transplantation - A systematic review and meta-analysis

This systematic review aimed to investigate the available quality of evidence (QOE) of enhanced recovery after surgery (ERAS) for liver transplantation (LT) on short-term outcomes, grade recommendations and identify relevant components for ERAS protocols. A systematic review and meta-analysis were conducted on short-term outcomes after LT when applying comprehensive ERAS protocols (>1 ERAS component) versus control groups (CRD42021210374), following the GRADE approach for grading quality of evidence and strength of recommendations. Endpoints were morbidity, mortality, length of stay and readmission rates after ERAS for LT. Of 858 screened articles, two randomized controlled trials, 2 prospective and 1 retrospective cohort studies were included (2002 - 2020). Frequent ERAS components were early extubation and postoperative antibiotic, fluid and nutrition management. Overall complications were reduced in ERAS versus control cohorts (OR 0.4 (CI 0.2, 0.7), with no significant differences in mortality and hospital readmission rates. Intensive care unit and hospital length of stay were shorter in ERAS groups (percentage decrease, 55% and 29%, respectively). QOE for individual outcomes was rated moderate to low. ERAS protocols in LT are related to improved short-term outcomes after liver transplantation (Quality of Evidence; Moderate to low | Grade of Recommendation; Strong), but currently lack standardization. This article is protected by copyright. All rights reserved.

Practice variation in the immediate postoperative care of pediatric liver transplant patients: Framework for a national consensus

Advancements in critical care management have led to improvement in pediatric LT outcomes. However, there are no specific guidelines for many aspects of immediate post-LT care. This survey examines practice variations in the immediate postoperative care of pediatric LT patients at a large number of active US centers. This study is a cross-sectional survey of medical directors at PALISI-affiliated PICU in the United States. Centers performing pediatric LT were analyzed. Study measures included PICU practices regarding staffing, composition of the multidisciplinary team, early post-LT graft and patient monitoring, and anticoagulation. Of the thirty-five responding centers, twenty-five had a LT program which accounted for one-half of all US pediatric LTs. For analysis, centers were categorized by volume: high (7), medium (11), and low (7). The majority of PICU teams included an intensivist (80%) and hepatologist (84%). High-volume centers were less likely to have 24-hour in-house attending coverage (29%, compared to 64% (medium) and 100% (low)). High-volume centers were most likely to have pre-printed orders, but least likely to have written PICU management protocols. Most centers utilize routine daily liver ultrasound. Routine prophylactic anticoagulation, and the agent of choice, was variable. There is marked inconsistency in post-LT practice across PALISI centers in regards to team composition and immediate post-LT management. A national US consensus for post-LT PICU practices would facilitate outcomes research and would establish a platform for multicenter studies.

Definition and Prospective Assessment of Functional Recovery After Liver Transplantation: A New Objective Consensus-Based Metric for Safe Discharge

Standardized discharge criteria are critical to reduce premature discharge and avoid unnecessary hospital stays. No such criteria exist for patients undergoing liver transplantation (LT). To achieve a consensus-based checklist of criteria for safe patient discharge after LT, this mixed-method study included the following: a systematic literature review and expert discussion to draft a first checklist of post-LT discharge criteria, defining patient recovery and indications for hospital discharge (functional recovery); an exploratory online electronic Delphi (e-Delphi) study; a single-center pilot study to test checklist feasibility; and a final e-Delphi study with an extended interdisciplinary expert panel to validate the final checklist. The first round provided a 10-point discharge checklist with 5 patient-centered items derived from discharge criteria after liver surgery and 5 graft-centered items derived from expert discussion. The restricted panel (9 experts) e-Delphi provided 100% consensus after the second round, with slight modifications to the criteria. During the pilot study, 19 of 45 (42.2%) patients included fulfilled the complete checklist (100% of 10 items) after median (IQR) 16 (8-21) days (functional recovery) and a length of stay of 20 (9-24) days. The item with the lowest completion rate was minimum serum tacrolimus level in the target on 2 consecutive blood samples (n = 21; 47%), achieved at 13 (9-15) days. The extended panel (66 experts) e-Delphi provided 95%-98% consensus after the third round, with slight modifications of the criteria. This study provided substantial consensus on discharge criteria after LT. We anticipate that these criteria will be useful in clinical practice to guide patient discharge and increase the comparability of results between future studies.

An international multicenter study of protocols for liver transplantation during a pandemic: A case for quadripartite equipoise

BACKGROUND & AIMS

The outbreak of COVID-19 has vastly increased the operational burden on healthcare systems worldwide. For patients with end-stage liver failure, liver transplantation is the only option. However, the strain on intensive care facilities caused by the pandemic is a major concern. There is an urgent need for ethical frameworks to balance the need for liver transplantation against the availability of national resources.

METHODS

We performed an international multicenter study of transplant centers to understand the evolution of policies for transplant prioritization in response to the pandemic in March 2020. To describe the ethical tension arising in this setting, we propose a novel ethical framework, the quadripartite equipoise (QE) score, that is applicable to liver transplantation in the context of limited national resources.

RESULTS

Seventeen large- and medium-sized liver transplant centers from 12 countries across 4 continents participated. Ten centers opted to limit transplant activity in response to the pandemic, favoring a "sickest-first" approach. Conversely, some larger centers opted to continue routine transplant activity in order to balance waiting list mortality. To model these and other ethical tensions, we computed a QE score using 4 factors - recipient outcome, donor/graft safety, waiting list mortality and healthcare resources - for 7 countries. The fluctuation of the QE score over time accurately reflects the dynamic changes in the ethical tensions surrounding transplant activity in a pandemic.

CONCLUSIONS

This four-dimensional model of quadripartite equipoise addresses the ethical tensions in the current pandemic. It serves as a universally applicable framework to guide regulation of transplant activity in response to the increasing burden on healthcare systems.

LAY SUMMARY

There is an urgent need for ethical frameworks to balance the need for liver transplantation against the availability of national resources during the COVID-19 pandemic. We describe a four-dimensional model of quadripartite equipoise that models these ethical tensions and can guide the regulation of transplant activity in response to the increasing burden on healthcare systems.

Approach to the liver transplant early postoperative period: an institutional standpoint

The liver transplant program in our center started in 1992, and post-liver transplant patients are still admitted to the intensive care unit. For the intensive care physician, a learning curve started then, skills were acquired, and a specific practice was established. Throughout this time, several concepts changed, improving the care of these patients. The practical approach varies between liver transplant centers, according to local specificities. Hence, we wanted to present our routine practice to stimulate the debate between dedicated teams, which can allow the introduction of new ideas and potentially improve each local standard of care.

A methodological review of clinical outcomes reported in liver transplantation trials

BACKGROUND

Liver Transplantation (LT) is a life-saving treatment for end-stage liver disease, for which various outcomes are measured in randomized clinical trials (RCT). The aim of this methodological review is to evaluate and classify outcomes reported in RCT in LT.

METHODS

PubMed and ClinicalTrials.gov were searched in July 2018 for published and ongoing RCTs on LT in the last 5 years. Studies were eligible if focusing on first LT in adult patients, with interventions during the perioperative period. Data extracted concerned LT characteristics, type of intervention, methodological characteristics and outcomes assessed.

RESULTS

Of 2685 references, 55 were included with a median of 78 (40-120) patients for published trials and planned to include 117 (55-218) patients for ongoing trials. Morbidity was the most frequently used as primary outcome in 37 published (67%) and 13 ongoing trials (54%). We identified 10 different definitions for graft dysfunction, 9 for recovery outcomes and 12 different time-points for mortality. For published trials, among the 397 outcomes specified in the method section, results were reported for 283 (71%).

CONCLUSION

Outcomes reported in LT trials are very heterogeneous. A consensus approach to develop a core outcome set (COS) should be considered allowing for comparisons of results across trials.

PROSPERO

CRD42018108146.

[Anesthesiological aspects of liver transplantation]

Liver transplantation (LTPL) is the only curative option for patients with end stage liver disease (ESLD) or with hepatocellular carcinoma (HCC). Eurotransplant in Leiden, the Netherlands, is responsible for organ allocation. The model of end stage liver disease (MELD) score, which describes the severity of the liver disease, is decisive for organ allocation. The heterogeneous patient collective and hepatic-related comorbidities and their dynamics represent challenges. The anesthesiologist is responsible for evaluating the overall prognosis, whereby cardiac, pulmonary, renal and neurological comorbidities must be taken into consideration. During LTPL surgery is divided into several stages. Besides volume management, heat preservation and coagulation management, major challenges for the anesthesiologist are hemodynamic stabilization and regulation of the acid-base balance.

Enhanced Recovery in Liver Transplantation: A Feasibility Study

BACKGROUND

Enhanced Recovery After Surgery (ERAS) programmes after surgery are effective in reducing length of stay, functional recovery and complication rates in liver surgery (LS) with the indirect advantage of reducing hospitalisation costs. Preoperative comorbidities, challenging surgical procedures and complex post-operative management are the points that liver transplantation (LT) shares with LS. Nevertheless, there is little evidence regarding the feasibility and safety of ERAS programmes in LT.

METHODS

We designed a pilot, small-scale, feasibility study to assess the impact on hospital stay, protocol compliance and safety of an ERAS programme tailored for LT. The ERAS arm was compared with a 1:2 match paired control arm with similar characteristics. All patients with MELD <25 were included. A dedicated LT-tailored protocol was derived from publications on ERAS liver surgery.

RESULTS

Ten patients were included in the Fast-Trans arm. It was observed a 47% reduction of the total LOS, as compared to the control arm: 9.5 (9.0-10.5) days versus 18.0 (14.3-24.3) days, respectively, p <0.001. The protocol achieved 72.9% compliance. No differences were observed in terms of post-operative complications or readmission rates after discharge between the two arms. Overall, it was observed a reduction of length of stay in ICU and surgical ward in the Fast-Trans arm compared with the control arm.

CONCLUSION

Considered the main points in common between LS and LT, this small-scale study suggests that the application of an ERAS programme tailored to the LT setting is feasible. Further testing will be appropriate to generalise these findings.

Delayed introduction of immunosuppressive regimens in critically ill patients after liver transplantation

BACKGROUND

The manipulation of immunosuppression therapy remains challenging in patients who develop infectious diseases or multiple organ dysfunction after liver transplantation. We evaluated the outcomes of delayed introduction of immunosuppression in the patients after liver transplantation under immune monitoring with ImmuKnow assay.

METHODS

From March 2009 to February 2014, 225 consecutive liver recipients in our institute were included. The delayed administration of immunosuppressive regimens was attempted in 11 liver recipients with multiple severe comorbidities.

RESULTS

The median duration of non-immunosuppression was 12 days (range 5-58). Due to the infectious complications, the serial ImmuKnow assay showed a significantly low ATP level of 64±35 ng/mL in the early period after transplantation. With the development of comorbidities, the ImmuKnow value significantly increased. However, the acute allograft rejection developed when a continuous distinct elevation of both ATP and glutamyltranspeptidase levels was detected. The average ATP level measured just before the development of acute rejection was 271±115 ng/mL.

CONCLUSIONS

The delayed introduction of immunosuppressive regimens is safe and effective in management of critically ill patients after liver transplantation. The serial ImmuKnow assay could provide a reliable depiction of the dynamics of functional immunity throughout the clinical course of a given patient.