Early outcomes of liver transplants in patients receiving organs from hypernatremic donors

Better liver transplant outcomes by donor interventions?

PURPOSE OF REVIEW

Donor risk factors and events surrounding donation impact the quantity and quality of grafts generated to meet liver transplant waitlist demands. Donor interventions represent an opportunity to mitigate injury and risk factors within donors themselves. The purpose of this review is to describe issues to address among donation after brain death, donation after circulatory determination of death, and living donors directly, for the sake of optimizing relevant outcomes among donors and recipients.

RECENT FINDINGS

Studies on donor management practices and high-level evidence supporting specific interventions are scarce. Nonetheless, for donation after brain death (DBD), critical care principles are employed to correct cardiocirculatory compromise, impaired tissue oxygenation and perfusion, and neurohormonal deficits. As well, certain treatments as well as marginally prolonging duration of brain death among otherwise stable donors may help improve posttransplant outcomes. In donation after circulatory determination of death (DCD), interventions are performed to limit warm ischemia and reverse its adverse effects. Finally, dietary and exercise programs have improved donation outcomes for both standard as well as overweight living donor (LD) candidates, while minimally invasive surgical techniques may offer improved outcomes among LD themselves.

SUMMARY

Donor interventions represent means to improve liver transplant yield and outcomes of liver donors and grafts.

Brazilian guidelines for the management of brain-dead potential organ donors. The task force of the AMIB, ABTO, BRICNet, and the General Coordination of the National Transplant System

OBJECTIVE

To contribute to updating the recommendations for brain-dead potential organ donor management.

METHOD

A group of 27 experts, including intensivists, transplant coordinators, transplant surgeons, and epidemiologists, joined a task force formed by the General Coordination Office of the National Transplant System/Brazilian Ministry of Health (CGSNT-MS), the Brazilian Association of Intensive Care Medicine (AMIB), the Brazilian Association of Organ Transplantation (ABTO), and the Brazilian Research in Intensive Care Network (BRICNet). The questions were developed within the scope of the 2011 Brazilian Guidelines for Management of Adult Potential Multiple-Organ Deceased Donors. The topics were divided into mechanical ventilation, hemodynamic support, endocrine-metabolic management, infection, body temperature, blood transfusion, and use of checklists. The outcomes considered for decision-making were cardiac arrest, number of organs recovered or transplanted per donor, and graft function/survival. Rapid systematic reviews were conducted, and the quality of evidence of the recommendations was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system. Two expert panels were held in November 2016 and February 2017 to classify the recommendations. A systematic review update was performed in June 2020, and the recommendations were reviewed through a Delphi process with the panelists between June and July 2020.

RESULTS

A total of 19 recommendations were drawn from the expert panel. Of these, 7 were classified as strong (lung-protective ventilation strategy, vasopressors and combining arginine vasopressin to control blood pressure, antidiuretic hormones to control polyuria, serum potassium and magnesium control, and antibiotic use), 11 as weak (alveolar recruitment maneuvers, low-dose dopamine, low-dose corticosteroids, thyroid hormones, glycemic and serum sodium control, nutritional support, body temperature control or hypothermia, red blood cell transfusion, and goal-directed protocols), and 1 was considered a good clinical practice (volemic expansion).

CONCLUSION

Despite the agreement among panel members on most recommendations, the grade of recommendation was mostly weak. The observed lack of robust evidence on the topic highlights the importance of the present guideline to improve the management of brain-dead potential organ donors.

Impact of donor sodium levels on clinical outcomes in liver transplant recipients: a systematic review

We performed a systematic review of the literature to examine the effects of donor sodium levels on liver graft function and recipient survival, as well as to identify the optimal serum sodium target in donors. We searched MEDLINE, Cochrane, and trial registries from 1946 to May 2019 for studies that evaluated the effect of serum sodium levels in neurologically deceased liver donors on transplant outcomes. We used a two-step review process with four independent reviewers to identify relevant articles based on inclusion/exclusion criteria. We summarize the results narratively, assess the risk of bias, and apply the Grading of Recommendations Assessment, Development, and Evaluation methods to evaluate the certainty in the evidence. We included 25 cohort studies were in our final analysis (total n = 19 389). Twenty-two reported on graft function and survival. Summary data suggest an association between donor serum sodium and recipient liver graft dysfunction, with very low certainty in evidence due to serious concerns with risk of bias, inconsistency, indirectness, and imprecision. Seven studies reported on recipient mortality, with results suggesting no association between donor sodium and recipient survival. The certainty in evidence for this outcome was also very low due to serious concerns with imprecision, indirectness, and risk of bias. Donor sodium dysregulation is associated with liver graft dysfunction, but not recipient mortality. Further research is needed to determine the effects of correcting donor sodium levels on transplant outcomes, quantify the dose-response curve, and identify liver recipients most vulnerable to sodium dysregulation.

Prognostic factors influencing outcome in adult liver transplantation using hypernatremic organ donation after brain death

BACKGROUND

Hypernatremic donors was regarded as the expanded criteria donors in liver transplantation. The study was to investigate the effects of donor hypernatremia on the outcomes of liver transplantation and identify the prognostic factors possibly contributing to the poor outcomes.

METHODS

Donor serum sodium levels before procurement were categorized as normal sodium (< 155 mmol/L), moderate high sodium (155-170 mmol/L), and severe high sodium (≥ 170 mmol/L). Furthermore, we subdivided the 142 hypernatremic donors (≥ 155 mmol/L) into two subgroups: subgroup A, the exposure time of liver grafts from hypernatremia to reperfusion was < 36 h; and subgroup B, the exposure time was ≥ 36 h. The outcomes included initial graft function, survival rates of grafts and recipients, graft loss and early events within the first year following liver transplantation.

RESULTS

There were no significant differences in the 1-year survival rates of grafts and recipients, 1-year graft loss rates and early events among the normal, moderate high and severe high sodium groups. However, the overall survival rates of grafts and recipients in subgroup A were significantly higher than those in subgroup B. Cox model showed that the exposure time (HR = 1.117; 95% CI: 1.053-1.186; P < 0.001), cold ischemia time (HR = 1.015; 95% CI: 1.006-1.024; P = 0.001) and MELD (HR = 1.061; 95% CI: 1.003-1.121; P = 0.037) were the important prognostic factors contributing to the poor outcomes of recipients with hypernatremic donors.

CONCLUSIONS

The level of donor sodium immediately before organ procurement does not have negative effects on the early outcomes following adult liver transplantation. For hypernatremia liver donors, minimization of the exposure time from hypernatremia to reperfusion is critical to prevent graft loss.

Diabetes Insipidus and Syndrome of Inappropriate Antidiuretic Hormone in Critically Ill Patients

Diabetes insipidus and the syndrome of inappropriate antidiuretic hormone secretion lie at opposite ends of the spectrum of disordered renal handling of water. Whereas renal retention of water insidiously causes hypotonic hyponatremia in syndrome of inappropriate antidiuretic hormone secretion, diabetes insipidus may lead to free water loss, hypernatremia, and volume depletion. Hypernatremia and hyponatremia are associated with worse outcomes and longer intensive care stays. Moreover, pathologies causing polyuria and hyponatremia in patients in intensive care may be multiple, making diagnosis challenging. We provide an approach to the diagnosis and management of these conditions in intensive care patients.

Extended criteria donors in liver transplantation Part I: reviewing the impact of determining factors

The definition and factors of extended criteria donors have already been set; however, details of the various opinions still differ in many respects. In this review, we summarize the impact of these factors and their clinical relevance. Elderly livers must not be allocated for hepatitis C virus (HCV) positives, or patients with acute liver failure. In cases of markedly increased serum transaminases, donor hemodynamics is an essential consideration. A prolonged hypotension of the donor does not always lead to an increase in post-transplantation graft loss if post-OLT care is proper. Hypernatremia of less than 160 mEq/L is not an absolute contraindication to accept a liver graft per se. The presence of steatosis is an independent and determinant risk factor for the outcome. The gold standard of the diagnosis is the biopsy. This is recommended in all doubtful cases. The use of HCV+ grafts for HCV+ recipients is comparable in outcome. The leading risk factor for HCV recurrence is the actual RNA positivity of the donor. The presence of a proper anti-HBs level seems to protect from de novo HBV infection. A favourable outcome can be expected if a donation after cardiac death liver is transplanted in a favourable condition, meaning, a warm ischemia time < 30 minutes, cold ischemia time < 8-10 hours, and donor age 50-60 years. The pathway of organ quality assessment is to obtain the most relevant information (e.g. biopsy), consider the co-existing donor risk factors and the reserve capacity of the recipient, and avoid further technical issues.

Strategies to optimize the use of marginal donors in liver transplantation

Liver transplantation is the treatment of choice for end stage liver disease, but availability of liver grafts is still the main limitation to its wider use. Extended criteria donors (ECD) are considered not ideal for several reasons but their use has dramatically grown in the last decades in order to augment the donor liver pool. Due to improvement in surgical and medical strategies, results using grafts from these donors have become acceptable in terms of survival and complications; nevertheless a big debate still exists regarding their selection, discharge criteria and allocation policies. Many studies analyzed the use of these grafts from many points of view producing different or contradictory results so that accepted guidelines do not exist and the use of these grafts is still related to non-standardized policies changing from center to center. The aim of this review is to analyze every step of the donation-transplantation process emphasizing all those strategies, both clinical and experimental, that can optimize results using ECD.