Management of the Brain-Dead Organ Donor: A Systematic Review and Meta-Analysis

Does liraglutide alleviate inflammation in brain-dead donors? A randomized clinical trial

Brain death triggers an inflammatory cascade that damages organs before procurement, adversely affecting the quality of grafts. This randomized clinical trial aimed to compare the efficacy of liraglutide compared to placebo in attenuating brain death-induced inflammation, endoplasmic reticulum stress, and oxidative stress. We conducted a double-blinded, placebo-controlled, randomized clinical trial with brain-dead donors. Fifty brain-dead donors were randomized to receive subcutaneous liraglutide or placebo. The primary outcome was the reduction in IL-6 plasma levels. Secondary outcomes were changes in other plasma pro-inflammatory (IL-1β, interferon-γ, TNF) and anti-inflammatory cytokines (IL-10), expression of antiapoptotic ( BCL2 ), endoplasmic reticulum stress markers ( DDIT3/CHOP , HSPA5/BIP ), and antioxidant ( superoxide dismutase 2 , uncoupling protein 2 ) genes, and expression TNF, DDIT3, and superoxide dismutase 2 proteins in liver biopsies. The liraglutide group showed lower cytokine levels compared to the placebo group during follow-up: Δ IL-6 (-28 [-182, 135] vs. 32 [-10.6, 70.7] pg/mL; p = 0.041) and Δ IL-10 (-0.01 [-2.2, 1.5] vs. 1.9 [-0.2, 6.1] pg/mL; p = 0.042), respectively. The administration of liraglutide did not significantly alter the expression of inflammatory, antiapoptotic, endoplasmic reticulum stress, or antioxidant genes in the liver tissue. Similar to gene expression, expressions of proteins in the liver were not affected by the administration of liraglutide. Treatment with liraglutide did not increase the organ recovery rate [OR = 1.2 (95% CI: 0.2-8.6), p = 0.82]. Liraglutide administration reduced IL-6 and prevented the increase of IL-10 plasma levels in brain-dead donors without affecting the expression of genes and proteins related to inflammation, apoptosis, endoplasmic reticulum stress, or oxidative stress.

Vasopressin Use in the Support of Organ Donors: Physiological Rationale and Review of the Literature

The objective of this review was to depict the physiological and clinical rationale for the use of vasopressin in hemodynamic support of organ donors. After summarizing the physiological, pharmacological concepts and preclinical findings, regarding vasopressin's pathophysiological impacts, we will present the available clinical data.

DATA SOURCES

Detailed search strategies in PubMed, OVID Medline, and EMBASE were undertaken using Medical Subject Headings and Key Words.

STUDY SELECTION

Physiological articles regarding brain death, and preclinical animal and human studies about the use of vasopressin or analogs, as an intervention in organ support for donation, were considered.

DATA EXTRACTION

Two authors independently screened titles, abstracts, and full text of articles to determine eligibility. Data encompassing models, population, methodology, outcomes, and relevant concepts were extracted.

DATA SYNTHESIS

Following brain death, profound reduction in sympathetic outflow is associated with reduced cardiac output, vascular tone, and hemodynamic instability in donors. In addition to reducing catecholamine needs and reversing diabetes insipidus, vasopressin has been shown to limit pulmonary injury and decrease systemic inflammatory response in animals. Several observational studies show the benefit of vasopressin on hemodynamic parameters and catecholamine sparing in donors. Small trials suggest that vasopressin increase organ procurement and have some survival benefit for recipients. However, the risk of bias is overall concerning, and therefore the quality of the evidence is deemed low.

CONCLUSIONS

Despite potential impact on graft outcome and a protective effect through catecholamine support sparing, the benefit of vasopressin use in organ donors is based on low evidence. Well-designed observational and randomized controlled trials are warranted.

Management of the Potential Lung Donor

The use of donor management protocols has significantly improved recovery rates; however, the inherent instability of lungs after death results in low utilization rates of potential donor lungs. Donor lungs are susceptible to direct trauma, aspiration, neurogenic edema, ventilator-associated barotrauma, and ventilator-associated pneumonia. After irreversible brain injury and determination of futility of care, the goal of medical management of the donor shifts to maintaining hemodynamic stability and maximizing the likelihood of successful organ recovery.

Hemodynamic Effects of High-dose Levothyroxine and Methylprednisolone in Brain-dead Potential Organ Donors

BACKGROUND

Hormonal replacement therapy is administered to many brain-dead organ donors to improve hemodynamic stability. Previous clinical studies present conflicting results with several randomized studies reporting no benefit.

METHODS

Consecutive adult donors (N = 199) were randomized to receive high-dose levothyroxine, high-dose methylprednisolone, both (Combo), or no hormonal therapy (Control). Vasopressor requirements using the vasoactive-inotropic score (VIS) were assessed at baseline, 4 h, and at procurement. Crossover to the Combo group was sufficient to require separate intention-to-treat and per-protocol analyses.

RESULTS

In the intention-to-treat analysis, the mean (±SD) reduction in VIS from baseline to procurement was 1.6 ± 2.6, 14.9 ± 2.6, 10.9 ± 2.6, and 7.1 ± 2.6 for the levothyroxine, methylprednisolone, Combo, and Control groups, respectively. While controlling for the baseline score, the reduction in VIS was significantly greater in the methylprednisolone and Combo groups and significantly less in the levothyroxine group compared with controls. Results were similar in the per-protocol analysis.

CONCLUSION

High-dose methylprednisolone alone or in combination with levothyroxine allowed for significant reduction in vasopressor support in organ donors. Levothyroxine alone offered no advantage in reducing vasopressor support. Organ yield, transplantation rates, and recipient outcomes were not adversely affected.

Peritransplant Cardiometabolic and Mitochondrial Function: The Missing Piece in Donor Heart Dysfunction and Graft Failure

Primary graft dysfunction is an important cause of morbidity and mortality after cardiac transplantation. Donor brain stem death (BSD) is a significant contributor to donor heart dysfunction and primary graft dysfunction. There remain substantial gaps in the mechanistic understanding of peritransplant cardiac dysfunction. One of these gaps is cardiac metabolism and metabolic function. The healthy heart is an "omnivore," capable of utilizing multiple sources of nutrients to fuel its enormous energetic demand. When this fails, metabolic inflexibility leads to myocardial dysfunction. Data have hinted at metabolic disturbance in the BSD donor and subsequent heart transplantation; however, there is limited evidence demonstrating specific metabolic or mitochondrial dysfunction. This review will examine the literature surrounding cardiometabolic and mitochondrial function in the BSD donor, organ preservation, and subsequent cardiac transplantation. A more comprehensive understanding of this subject may then help to identify important cardioprotective strategies to improve the number and quality of donor hearts.

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.

Pediatric donor management to optimize donor heart utilization

Optimal management of pediatric cardiac donors is essential in order to maximize donor heart utilization and minimize the rate of discarded organs. This review was performed after a systematic literature review and gives a detailed overview on current practices and guidelines. The review focuses on optimal monitoring of pediatric donors, donor workup, hormonal replacement, and obliterating the adverse effects of brain death. The current evidence on catecholamine support and thyroid hormone replacement is also discussed. Recognizing and addressing this shall help in a standardized approach toward donor management and optimal utilization of pediatric heart donors organs.

DONORS (Donation Network to Optimise Organ Recovery Study): Study protocol to evaluate the implementation of an evidence-based checklist for brain-dead potential organ donor management in intensive care units, a cluster randomised trial

INTRODUCTION

There is an increasing demand for multi-organ donors for organ transplantation programmes. This study protocol describes the Donation Network to Optimise Organ Recovery Study, a planned cluster randomised controlled trial that aims to evaluate the effectiveness of the implementation of an evidence-based, goal-directed checklist for brain-dead potential organ donor management in intensive care units (ICUs) in reducing the loss of potential donors due to cardiac arrest.

METHODS AND ANALYSIS

The study will include ICUs of at least 60 Brazilian sites with an average of ≥10 annual notifications of valid potential organ donors. Hospitals will be randomly assigned (with a 1:1 allocation ratio) to the intervention group, which will involve the implementation of an evidence-based, goal-directed checklist for potential organ donor maintenance, or the control group, which will maintain the usual care practices of the ICU. Team members from all participating ICUs will receive training on how to conduct family interviews for organ donation. The primary outcome will be loss of potential donors due to cardiac arrest. Secondary outcomes will include the number of actual organ donors and the number of organs recovered per actual donor.

ETHICS AND DISSEMINATION

The institutional review board (IRB) of the coordinating centre and of each participating site individually approved the study. We requested a waiver of informed consent for the IRB of each site. Study results will be disseminated to the general medical community through publications in peer-reviewed medical journals.

TRIAL REGISTRATION NUMBER

NCT03179020; Pre-results.

Catastrophic Non-Survivable Brain Injury Care-Role 2/3

A catastrophic brain injury is defined as any brain injury that is expected to result in permanent loss of all brain function above the brain stem level. These clinical recommendations will help stabilize the patient so that they may be safely evacuated from theater. In addition to cardiovascular and hemodynamic goals, special attention must be paid to their endocrine dysfunction and its treatment-specifically steroid, insulin and thyroxin (t4) replacement while evaluating for and treating diabetes insipidus. Determining the futility of care coupled with resource management must also be made at each echelon. Logistical coordination and communication is paramount to expedite these patients to higher levels of care so that there is an increased probability of reuniting them with their family.

Medical Management of Brain-Dead Organ Donors

With improving healthcare services, the demand for organ transplants has been increasing daily worldwide. Deceased organ donors serve as a good alternative option to meet this demand. The first step in this process is identifying potential organ donors. Specifically, brain-dead patients require aggressive and intensive care from the declaration of brain death until organ retrieval. Currently, there are no specific protocols in place for this, and there are notable variations in the management strategies implemented across different transplant centers. Some transplant centers follow their own treatment protocols, whereas other countries, such as Bangladesh, do not have any protocols for potential organ donor care. In this review, we discuss how to identify brain-dead donors and describe the physiological changes that occur following brain death. We then summarize the management of brain-dead organ donors and, on the basis of a review of the literature, we propose recommendations for a treatment protocol to be developed in the future.

Renal effects of exendin-4 in an animal model of brain death

Organ transplantation is the gold standard therapy for the majority of patients with terminal organ failure. However, it is still a limited treatment especially due to the low number of brain death (BD) donors in relation to the number of waiting list recipients. Strategies to increase the quantity and quality of donor organs have been studied, and the administration of exendin-4 (Ex-4) to the donor may be a promising approach. Male Wistar rats were randomized into 3 groups: (1) control, without central nervous system injury; (2) BD induced experimentally, and (3) BD induced experimentally + Ex-4 administered immediately after BD induction. After BD induction, animals were monitored for 6 h before blood collection and kidney biopsy. Kidney function was assessed by biochemical quantification of plasma kidney markers. Gene and protein expressions of inflammation- and stress-related genes were evaluated by RT-qPCR and immunoblot analysis. Animals treated with Ex-4 had lower creatinine and urea levels compared with controls. BD induced oxidative stress in kidney tissue through increased expression of Ucp2, Sod2 and Inos, and Ex-4 administration reduced the expression of these genes. Ex-4 also induced increased expression of the anti-apoptotic Bcl2 gene. Nlrp3 and Tnf expressions were up-regulated in the BD group compared with controls, but Ex-4 treatment had no effect on these genes. Our findings suggest that Ex-4 administration in BD rats reduces BD-induced kidney damage by decreasing the expression of oxidative stress genes and increasing the expression of Bcl2.

Novel Fusion Protein Targeting Mitochondrial DNA Improves Pancreatic Islet Functional Potency and Islet Transplantation Outcomes

Long-term graft survival is an ongoing challenge in the field of islet transplantation. With the growing demand for transplantable organs, therapies to improve organ quality and reduce the incidence of graft dysfunction are of paramount importance. We evaluated the protective role of a recombinant DNA repair protein targeted to mitochondria (Exscien I-III), as a therapeutic agent using a rodent model of pancreatic islet transplantation. We first investigated the effect of therapy on isolated rat islets cultured with pro-inflammatory cytokines (interleukin-1 β, interferon γ, and tumor necrosis factor α) for 48 h and documented a significant reduction in apoptosis by flow cytometry, improved viability by immunofluorescence, and conserved functional potency in vitro and in vivo in Exscien I-III-treated islets. We then tested the effect of therapy in systemic inflammation using a rat model of donor brain death (BD) sustained for a 6-h period. Donor rats were allocated to 4 groups: (non-BD + vehicle, non-BD + Exscien I-III, BD + vehicle, and BD + Exscien I-III) and treated with Exscien I-III (4 mg/kg) or vehicle 30 min after BD induction. Sham (non-BD)-operated animals receiving either Exscien I-III or vehicle served as controls. Islets purified from BD + Exscien I-III-treated donors showed a significant increase in glucose-stimulated insulin release in vitro when compared to islets from vehicle-treated counterparts. In addition, donor treatment with Exscien I-III attenuated the effects of BD and significantly improved the functional potency of transplanted islets in vivo. Our data indicate that mitochondrially targeted antioxidant therapy is a novel strategy to protect pancreas and islet quality from the deleterious effects of cytokines in culture and during the inflammatory response associated with donation after BD. The potential for rapid translation into clinical practice makes Exscien I-III an attractive therapeutic option for the management of brain-dead donors or as an additive to islets in culture after isolation setting.

Adherence to guidelines for the management of donors after brain death

PURPOSE

Guideline adherence for the management of a donor after brain death (DBD) is largely unknown. This study aimed to perform an importance-performance analysis of prioritized key interventions (KIs) by linking guideline adherence rates to expert consensus ratings for the management of a DBD.

MATERIALS AND METHODS

This observational, cross-sectional multicenter study was performed in 21 Belgian ICUs. A retrospective review of patient records of adult utilized DBDs between 2013 and 2016 used 67 KIs to describe adherence to guidelines.

RESULTS

A total of 296 patients were included. Thirty-five of 67 KIs had a high level of adherence congruent to a high expert panel rating of importance. Nineteen of 67 KIs had a low level of adherence in spite of a high level of importance according to expert consensus. However, inadequate documentation proved an important issue, hampering true guideline adherence assessment. Adherence ranged between 3 and 100% for single KI items and on average, patients received 72% of the integrated expert panel recommended care set.

CONCLUSIONS

Guideline adherence to an expert panel predefined care set in DBD donor management proved moderate leaving substantial room for improvement. An importance-performance analysis can be used to improve implementation and documentation of guidelines.

Development of key interventions and quality indicators for the management of an adult potential donor after brain death: a RAND modified Delphi approach

Background

A substantial degree of variability in practices exists amongst donor hospitals regarding the donor detection, determination of brain death, application of donor management techniques or achievement of donor management goals. A possible strategy to standardize the donation process and to optimize outcomes could lie in the implementation of a care pathway. The aim of the study was to identify and select a set of relevant key interventions and quality indicators in order to develop a specific care pathway for donation after brain death and to rigorously evaluate its impact.

Methods

A RAND modified three-round Delphi approach was used to build consensus within a single country about potential key interventions and quality indicators identified in existing guidelines, review articles, process flow diagrams and the results of the Organ Donation European Quality System (ODEQUS) project. Comments and additional key interventions and quality indicators, identified in the first round, were evaluated in the following rounds and a subsequent physical meeting. The study was conducted over a 4-month time period in 2016.

Results

A multidisciplinary panel of 18 Belgian experts with different relevant backgrounds completed the three Delphi rounds. Out of a total of 80 key interventions assessed throughout the Delphi process, 65 were considered to contribute to the quality of care for the management of a potential donor after brain death; 11 out of 12 quality indicators were validated for relevance and feasibility. Detection of all potential donors after brain death in the intensive care unit and documentation of cause of no donation were rated as the most important quality indicators.

Conclusions

Using a RAND modified Delphi approach, consensus was reached for a set of 65 key interventions and 11 quality indicators for the management of a potential donor after brain death. This set is considered to be applicable in quality improvement programs for the care of potential donors after brain death, while taking into account each country’s legislation and regulations regarding organ donation and transplantation.

Electronic supplementary material

The online version of this article (10.1186/s12913-018-3386-1) contains supplementary material, which is available to authorized users.

Systematic review on the treatment of deceased organ donors

BACKGROUND

Currently, there is no consensus on which treatments should be a part of standard deceased-donor management to improve graft quality and transplantation outcomes. The objective of this systematic review was to evaluate the effects of treatments of the deceased, solid-organ donor on graft function and survival after transplantation.

METHODS

Pubmed, Embase, Cochrane, and Clinicaltrials.gov were systematically searched for randomized controlled trials that compared deceased-donor treatment versus placebo or no treatment.

RESULTS

A total of 33 studies were selected for this systematic review. Eleven studies were included for meta-analyses on three different treatment strategies. The meta-analysis on methylprednisolone treatment in liver donors (two studies, 183 participants) showed no effect of the treatment on rates of acute rejection. The meta-analysis on antidiuretic hormone treatment in kidney donors (two studies, 222 participants) indicates no benefit in the prevention of delayed graft function. The remaining meta-analyses (seven studies, 334 participants) compared the effects of 10 min of ischaemic preconditioning on outcomes after liver transplantation and showed that ischaemic preconditioning improved short-term liver function, but not long-term transplant outcomes.

CONCLUSIONS

There is currently insufficient evidence to conclude that any particular drug treatment or any intervention in the deceased donor improves long-term graft or patient survival after transplantation.

Organ-specific responses during brain death: increased aerobic metabolism in the liver and anaerobic metabolism with decreased perfusion in the kidneys

Hepatic and renal energy status prior to transplantation correlates with graft survival. However, effects of brain death (BD) on organ-specific energy status are largely unknown. We studied metabolism, perfusion, oxygen consumption, and mitochondrial function in the liver and kidneys following BD. BD was induced in mechanically-ventilated rats, inflating an epidurally-placed Fogarty-catheter, with sham-operated rats as controls. A 9.4T-preclinical MRI system measured hourly oxygen availability (BOLD-related R2*) and perfusion (T1-weighted). After 4 hrs, tissue was collected, mitochondria isolated and assessed with high-resolution respirometry. Quantitative proteomics, qPCR, and biochemistry was performed on stored tissue/plasma. Following BD, the liver increased glycolytic gene expression (Pfk-1) with decreased glycogen stores, while the kidneys increased anaerobic- (Ldha) and decreased gluconeogenic-related gene expression (Pck-1). Hepatic oxygen consumption increased, while renal perfusion decreased. ATP levels dropped in both organs while mitochondrial respiration and complex I/ATP synthase activity were unaffected. In conclusion, the liver responds to increased metabolic demands during BD, enhancing aerobic metabolism with functional mitochondria. The kidneys shift towards anaerobic energy production while renal perfusion decreases. Our findings highlight the need for an organ-specific approach to assess and optimise graft quality prior to transplantation, to optimise hepatic metabolic conditions and improve renal perfusion while supporting cellular detoxification.

Organ-Protective Intensive Care in Organ Donors

BACKGROUND

The ascertainment of brain death (the irreversible, total loss of brain function) gives the physician the opportunity to limit or stop further treatment. Alternatively, if the brain-dead individual is an organ donor, the mode of treatment can be changed from patient-centered to donationcentered. Consensus-derived recommendations for the organ-protective treatment of brain-dead organ donors are not yet available in Germany.

METHODS

This review is based on pertinent publications retrieved by a selective search in PubMed, and on the authors' clinical experience.

RESULTS

Brain death causes major pathophysiological changes, including an increase in catecholamine levels and a sudden drop in the concentration of multiple hormones, among them antidiuretic hormone, cortisol, insulin, and triand tetraiodothyronine. These changes affect the function of all organ systems, as well as the hemodynamic state and the regulation of body temperature. The use of standardized donor management protocols might well increase the rate of transplanted organs per donor and improve the quality of the transplanted organs. In addition, the administration of methylprednisolone, desmopressin, and vasopressin could be a useful supplement to treatment in some cases. Randomized controlled trials have not yet demonstrated either improved organ function or prolonged survival of the transplant recipients.

CONCLUSION

The evidence base for organ-protective intensive care is weak; most of the available evidence is on the level of expert opinion. There is good reason to believe, however, that the continuation of intensive care, in the sense of early donor management, can make organ transplantation more successful both by increasing the number of transplantable organs and by improving organ quality.

Ischemia/reperfusion-associated tubular cells injury in renal transplantation: Can metabolomics inform about mechanisms and help identify new therapeutic targets?

Tubular cells are central targets of ischemia-reperfusion (I/R) injury in kidney transplantation. Inflammation and metabolic disturbances occurring within these cells are deleterious by themselves but also favor secondary events, such as activation of immune response. It is critical to have an in depth understanding of the mechanisms governing tubular cells response to I/R if one wants to define pertinent biomarkers or to elaborate targeted therapeutic interventions. As oxidative damage was shown to be central in the patho-physiological mechanisms, the impact of I/R on proximal tubular cells metabolism has been widely studied, contrary to its effects on expression and activity of membrane transporters of the proximal tubular cells. Yet, temporal modulation of transporters over ischemia and reperfusion periods appears to play a central role, not only in the induction of cells injury but also in graft function recovery. Metabolomics in cell models or diverse biofluids has the potential to provide large pictures of biochemical consequences of I/R. Metabolomic studies conducted in experimental models of I/R or in transplanted patients indeed retrieved metabolites belonging to the pathways known to be particularly affected. Interestingly, they also revealed that metabolic disturbances and transporters activities are in very close mutual interplay. As well as helping to select diagnostic biomarkers, such analyses could also contribute to identify new pharmacological targets and to set up innovative nephroprotective strategies for the future. Even if various therapeutic approaches have been evaluated for a long time to prevent or treat I/R injuries, metabolomics has helped identifying new ones, those related to membrane transporters seeming to be of particular interest. However, considering the very complex and multifactorial effects of I/R in the context of kidney transplantation, all tracks must be followed if one wants to prevent or limit its deleterious consequences.

Organ Donor Management: Part 1. Toward a Consensus to Guide Anesthesia Services During Donation After Brain Death

Worldwide 715 482 patients have received a lifesaving organ transplant since 1988. During this time, there have been advances in donor management and in the perioperative care of the organ transplant recipient, resulting in marked improvements in long-term survival. Although the number of organs recovered has increased year after year, a greater demand has produced a critical organ shortage. The majority of organs are from deceased donors; however, some are not suitable for transplantation. Some of this loss is due to management of the donor. Improved donor care may increase the number of available organs and help close the existing gap in supply and demand. In order to address this concern, The Organ Donation and Transplantation Alliance, the Association of Organ Procurement Organizations, and the Transplant and Critical Care Committees of the American Society of Anesthesiologists have formulated evidence-based guidelines, which include a call for greater involvement and oversight by anesthesiologists and critical care specialists, as well as uniform reporting of data during organ procurement and recovery.

Knowledge of the Concept of Brain Death Among the Latin-American Population Residing in Spain

OBJECTIVES

The knowledge of brain death is fundamental for being able to understand the organ donation process and for ensuring its acceptance or rejection. Here, we analyzed the level of knowledge of the concept of brain death among Latin-American individuals who are residents of Spain to determine the factors affecting this knowledge.

MATERIALS AND METHODS

Our patient group was a sample of 1314 Latin-American residents of Spain, obtained randomly and stratified according to the respondent's nationality, age, and sex. Their attitude was assessed using a validated questionnaire. The survey was self-administered and completed anonymously.

RESULTS

The questionnaire completion rate was 94% (n = 1237). Of total respondents, 25% (n = 313) knew the concept of brain death, which they considered to be an individual's death, 56% (n = 697) did not know the term, and 19% (n = 227) believed that it did not mean death. The variables related to knowledge of the brain death concept included (1) country of origin, with a better knowledge among those with Mexican nationality (P < .001); (2) male sex (30% vs 23%; P = .003); (3) having university-level education (35% vs 23%; P = .044); (4) having discussed the matter within the family (29% vs 23%; P = .044); (5) having a partner with a favorable attitude toward donation (39% vs 21%; P = .001); and (6) the respondent's religion (47% vs 7%; P < .001). The following factors persisted in the multivariate analysis: country of origin (odds ratio of 2.972), sex (odds ratio of 1.416), education level (odds ratio of 2.228), attitude of the respondent's partner (odds ratio of 1.835), and religion (odds ratio of 4.490).

CONCLUSIONS

Knowledge of the concept of brain death is limited among Latin-American residents of Spain, with marked differences among country of origin and other socio-personal factors.

Anesthesia Management of Organ Donors

The shortage of suitable organs is the biggest obstacle for transplants. At present, most organs for transplant in the United States are from donation after neurologic determination of death (brain death). Potential organs for transplant need to maintain their viability during a series of insults, including the original disease, physiologic derangements during the dying process, ischemia, and reperfusion. Proper donor management before, during, and after procurement has potential to increase the number and quality of organs from donors. Anesthesiologists need to understand the physiologic derangements associated with brain death and the updated donor management during the periprocurement period.

Emerging graft protective strategies in clinical liver transplantation

There have been remarkable efforts to characterize the key responsible pathophysiologic mechanisms, as well as to ameliorate the organ preservation and ischemia reperfusion injury with the ultimate goal of expanding the donor pool and further improvement of the outcomes of liver transplantation. Attempts to translate the experimental results from bench to bedside have yielded no valid protective concepts in the field of clinical liver transplantation yet. Nonetheless, there has been a considerable amount of ongoing clinical research to develop clinically relevant graft protective strategies. Areas covered: This review focuses on the most recent evidence based findings and ongoing clinical trials that might lead to emerging graft protective strategies in the field of clinical liver transplantation. New evidence-based findings in the donor preconditioning, organ preservation, and perioperative pharmacologic graft protection strategies in the recipient are reviewed. Expert commentary: Few strategies have been shown to exert some graft protective effects against ischemia reperfusion injury in recent clinical trials in liver transplantation. Among others, 'dynamic graft preservation' techniques have been emerging as more promising graft optimization strategies.

Effect of corticosteroid administration on neurologically deceased organ donors and transplant recipients: a systematic review and meta-analysis

OBJECTIVES

This review investigates the impact of corticosteroids on donation rates and transplant outcomes in light of findings from randomised controlled trials (RCTs) and to highlight the sources of uncertainty in this unresolved donor management issue.

DATA SOURCES

We searched electronic databases, trial registries and conference proceedings for RCTs evaluating corticosteroid therapy in neurologically deceased donors.

STUDY SELECTION AND DATA EXTRACTION

Independent reviewers assessed eligibility, evaluated risk of bias and abstracted data, including donor haemodynamic data, number of organs recovered and transplant outcomes. Where possible, we pooled results. For each outcome, we assessed the overall quality of evidence using The Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology.

DATA SYNTHESIS

Eleven RCTs with different corticosteroid regimens were included. Most trials assessed a once-daily infusion of methylprednisolone. Aside from one study showing improved liver graft function, no individual study or pooled analysis showed benefit of corticosteroids for any outcome: vasopressor use (three trials; relative risk (RR) 0.96; 95% CI 0.89 to 1.05), multiple organs recovered (two trials; RR 0.82; 95% CI 0.61 to 1.11), acute graft rejection (three trials; RR 0.91; 95% CI 0.60 to 1.39) or graft dysfunction (eight trials; RR 1.01; 95% CI 0.83 to 1.24). Two trials investigated adverse effects and found similar rates between groups. Quality of evidence was moderate or low for all outcomes.

CONCLUSION

Current clinical trials are limited in numbers and size to identify benefits or harms of corticosteroid therapy for deceased organ donors. In the face of these results, administering or withholding steroids both appear reasonable courses of action.

Organ donor management: Eight common recommendations and actions that deserve reflection

Despite major advances in our understanding of the physiopathology of brain death (BD), there are important controversies as to which protocol is the most appropriate for organ donor management. Many recent reviews on this subject offer recommendations that are sometimes contradictory and in some cases are not applied to other critically ill patients. This article offers a review of the publications (many of them recent) with an impact upon these controversial measures and which can help to confirm, refute or open new areas of research into the most appropriate measures for the management of organ donors in BD, and which should contribute to discard certain established recommendations based on preconceived ideas, that lead to actions lacking a physiopathological basis. Aspects such as catecholamine storm management, use of vasoactive drugs, hemodynamic objectives and monitoring, assessment of the heart for donation, and general care of the donor in BD are reviewed.

Study of the Role of Transforming Growth Factor β-1 in Organ Damage Protection in Porcine Model of Brain Death

BACKGROUND

From the medical and ethical points of view, donation after brain death is a more acceptable organ source than that from a living donor because it has the advantage of providing multiple organs from a single donor source. Hence, it has become a more promising field of research which focuses on the protection of organs at brain death Here we investigated the role of transforming growth factor (TGF)-β1 in a porcine model of brain death.

METHODS

A porcine model of brain death was established by increasing the intracranial pressure (ICP) after which TGF-β1 was monitored by immunofluorescence at the following time points: before ICP was performed (t1), at brain death (t2), and at 3 (t3), 6 (t4), 9 (t5), and 18 (t6) hours after brain death. The data were analyzed using the fixed effect regression method and the correlation between the results was determined by Pearson analysis.

RESULTS

Our results showed that there was a significant increase in the levels of TGF-β1 (P < .05), urea (P < .01), creatinine (P < .01), and aspartate aminotransferase (AST; P < .01) during the 18-hour brain death process. There were negative correlations between TGF-β1 and urea, creatinine, alanine aminotransferase, AST, and total bilirubin. The negative correlations between TGF-β1 and creatinine and AST achieved statistical significance (P < .05).

CONCLUSIONS

These findings taken together confirm that significant damages are caused to the myocardial fiber cell and kidney glomerulus during brain death process, and that TGF-β1 is associated with the protection of these organs.

How can we improve the quality of transplantable lungs?

INTRODUCTION

Optimization of lungs for organ donation is becoming increasingly important as donation rates stagnate despite growing waiting lists. Improving procurement and utilization of donated lungs has the ability to reduce mortality and time on the lung transplantation (LTx) waiting list. Additionally, assessment and optimization of donor lungs can reduce both early and late post-LTx morbidity and mortality, as well as reduce overall costs and resource utility. Areas covered: Strategies that we will discuss in detail include intensive care management practices, such as targeted ventilation protocols and therapeutic bronchoscopy, as well as the ever expanding possibilities within the arena of ex vivo lung perfusion (EVLP). Expert commentary: Donor lung quality is currently optimized both in vivo prior to organ procurement, and also via EVLP circuits. Despite good evidence demonstrating the utility of both approaches, data remain elusive as to whether EVLP is beneficial for all donor lungs prior to implantation, or instead as a tool by which we can evaluate and recondition sub-optimal donor lungs.

Recommendations for further improvement of the deceased organ donation process in Belgium

Belgium has achieved high deceased organ donation rates but according to the medical record data in the Donor Action database, deceased potential donors are still missed along the pathway. Between 2010 and 2014, 12.9 ± 3.3% of the potential donors after brain death (DBD) and 24.6 ± 1.8% of the potential donors after circulatory (DCD) death were not identified. Conversion rates of 41.7 ± 2.1% for DBD and 7.9 ± 0.9% for DCD indicate room for further improvement. We identify and discuss different issues in the monitoring of donation activities, practices and outcomes; donor pool; legislation on deceased organ donation; registration; financial reimbursement; educational and training programs; donor detection and practice clinical guidance. The overall aim of this position paper, elaborated by a Belgian expert panel, is to provide recommendations for further improvement of the deceased organ donation process up to organ procurement in Belgium.

Prediction, prevention, and management of delayed graft function: where are we now?

Delayed graft function (DGF) remains a major barrier to improved outcomes after kidney transplantation. High-risk transplant recipients can be identified, but no definitive prediction model exists. Novel biomarkers to predict DGF in the first hours post-transplant, such as neutrophil gelatinase-associated lipocalin (NGAL), are under investigation. Donor management to minimize the profound physiological consequences of brain death is highly complex. A hormonal resuscitation package to manage the catecholamine "storm" that follows brain death is recommended. Donor pretreatment with dopamine prior to procurement lowers the rate of DGF. Hypothermic machine perfusion may offer a significant reduction in the rate of DGF vs simple cold storage, but costs need to be evaluated. Surgically, reducing warm ischemia time may be advantageous. Research into recipient preconditioning options has so far not generated clinically helpful interventions. Diagnostic criteria for DGF vary, but requirement for dialysis and/or persistent high serum creatinine is likely to remain key to diagnosis until current work on early biomarkers has progressed further. Management centers on close monitoring of graft (non)function and physiological parameters. With so many unanswered questions, substantial reductions in the toll of DGF in the near future seem unlikely but concentrated research on many levels offers long-term promise.

The role of hormone replacement therapy in the intensive care management of deceased organ donors: a primer for nurses

Donation after brain death remains the primary contributor to the supply of organs available for transplantation in the United States. After brain death, both a surge of catecholamines and a dysregulation of the neurohormonal axis may result in hypotension, decreased organ perfusion, and reduced viability of organs to be transplanted. Hormone replacement therapy is widely used to maintain organ perfusion and has been shown to increase the number of organs procured. This article reviews the literature and mechanisms supporting the use of hormone replacement therapy in brain-dead organ donors and provides clinicians with information regarding the administration, monitoring, and preparation of thyroid hormone, arginine vasopressin, and corticosteroids.

Anti-Apoptotic Effects of 3,3',5-Triiodo-L-Thyronine in the Liver of Brain-Dead Rats

Background

Thyroid hormone treatment in brain-dead organ donors has been extensively studied and applied in the clinical setting. However, its clinical applicability remains controversial due to a varying degree of success and a lack of mechanistic understanding about the therapeutic effects of 3,3’,5-Triiodo-L-thyronine (T₃). T₃ pre-conditioning leads to anti-apoptotic and pro-mitotic effects in liver tissue following ischemia/reperfusion injury. Therefore, we aimed to study the effects of T₃ pre-conditioning in the liver of brain-dead rats.

Methods

Brain death (BD) was induced in mechanically ventilated rats by inflation of a Fogarty catheter in the epidural space. T₃ (0.1 mg/kg) or vehicle was administered intraperitoneally 2 h prior to BD induction. After 4 h of BD, serum and liver tissue were collected. RT-qPCR, routine biochemistry, and immunohistochemistry were performed.

Results

Brain-dead animals treated with T₃ had lower plasma levels of AST and ALT, reduced Bax gene expression, and less hepatic cleaved Caspase-3 activation compared to brain-dead animals treated with vehicle. Interestingly, no differences in the expression of inflammatory genes (IL-6, MCP-1, IL-1β) or the presence of pro-mitotic markers (Cyclin-D and Ki-67) were found in brain-dead animals treated with T₃ compared to vehicle-treated animals.

Conclusion

T₃ pre-conditioning leads to beneficial effects in the liver of brain-dead rats as seen by lower cellular injury and reduced apoptosis, and supports the suggested role of T₃ hormone therapy in the management of brain-dead donors.

Exendin-4 protects rat islets against loss of viability and function induced by brain death

Islet quality loss after isolation from brain-dead donors still hinders the implementation of human islet transplantation for treatment of type 1 diabetes. In this scenario, systemic inflammation elicited by donor brain death (BD) is among the main factors influencing islet viability and functional impairment. Exendin-4 is largely recognized to promote anti-inflammatory and cytoprotective effects on β-cells. Therefore, we hypothesized that administration of exendin-4 to brain-dead donors might improve islet survival and insulin secretory capabilities. Here, using a rat model of BD, we demonstrate that exendin-4 administration to the brain-dead donors increases both islet viability and glucose-stimulated insulin secretion. In this model, exendin-4 treatment produced a significant decrease in interleukin-1β expression in the pancreas. Furthermore, exendin-4 treatment increased the expression of superoxide dismutase-2 and prevented BD-induced elevation in uncoupling protein-2 expression. Such observations were accompanied by a reduction in gene expression of two genes often associated with endoplasmic reticulum (ER) stress response in freshly isolated islets from treated animals, C/EBP homologous protein and immunoglobulin heavy-chain binding protein. As ER stress response has been shown to be triggered by and to participate in cytokine-induced β-cell death, we suggest that exendin-4 might exert its beneficial effects through alleviation of pancreatic inflammation and oxidative stress, which in turn could prevent islet ER stress and β-cell death. Our findings might unveil a novel strategy to preserve islet quality from brain-dead donors. After testing in the human pancreatic islet transplantation setting, this approach might sum to the ongoing effort to achieve consistent and successful single-donor islet transplantation.

Cardio-pulmonary resuscitation of brain-dead organ donors: a literature review and suggestions for practice

"Organ preserving cardiopulmonary resuscitation (OP-CPR)" is defined as the use of CPR in cases of cardiac arrest to preserve organs for transplantation, rather than to revive the patient. Is it ethical to provide OP-CPR in a brain-dead organ donor to save organs that would otherwise be lost? To answer this question, we review the literature on brain-dead organ donors, conduct an ethical analysis, and make recommendations. We conclude that OP-CPR can benefit patients and families by fulfilling the wish to donate. However, it is an aggressive procedure that can cause physical damage to patients, and risks psychological harm to families and healthcare professionals. In a brain-dead organ donor, OP-CPR is acceptable without specific informed consent to OP-CPR, although advance discussion with next of kin regarding this possibility is strongly advised. In a patient where brain death is yet to be determined, but there is known wish for organ donation, OP-CPR would only be acceptable with a specific informed consent from the next of kin. When futility of treatment has not been established or it is as yet unknown if the patient wished to be an organ donor then OP-CPR should be prohibited, in order to avoid any conflict of interest.

Increased Procurement of Thoracic Donor Organs After Thyroid Hormone Therapy

Hormonal therapy to the brain-dead organ donor can include thyroid hormone (triiodothyronine [T3] or levothyroxine [T4]), antidiuretic hormone, corticosteroids, or insulin. There has been a controversy on whether thyroid hormone enables more organs to be procured. Data on 63,593 donors of hearts and lungs (2000-2009) were retrospectively reviewed. Documentation on T3/T4 was available in all donors (study 1), and in 40,124 details of all 4 hormones were recorded (study 2). In this cohort, group A (23,022) received T3/T4 and group B (17,102) no T3/T4. Univariate analyses and multiple regressions were performed. Posttransplant graft and recipient survival at 1 and 12 months were compared. In study 1, 30,962 donors received T3/T4, with 36.59% providing a heart and 20.05% providing 1 or both lungs. Of the 32,631 donors who did not receive T3/T4, only 29.62% provided a heart and 14.61% provided lungs, an increase of 6.97% hearts and 5.44% lungs from T3/T4-treated donors (both P < 0.0001). In study 2, 34.99% of group A provided a heart and 20.99% provided lungs. In group B only 25.76% provided a heart and 15.09% provided lungs, an increase of 9.23% (hearts) and 5.90% (lungs), respectively, in group A (both P < 0.0001). The results of multiple regression analyses indicated a beneficial effect of T3/T4 on heart (P < 0.0001) and lung (P < 0.0001) procurement independent of other factors. T3/T4 therapy to the donor was associated with either improved posttransplant graft and recipient survival or no difference in survival. T3/T4 therapy results in more transplantable hearts and lungs, with no detriment to posttransplant graft or recipient survival.

MicroRNAs in liver tissue engineering - New promises for failing organs

miRNA-based technologies provide attractive tools for several liver tissue engineering approaches. Herein, we review the current state of miRNA applications in liver tissue engineering. Several miRNAs have been implicated in hepatic disease and proper hepatocyte function. However, the clinical translation of these findings into tissue engineering has just begun. miRNAs have been successfully used to induce proliferation of mature hepatocytes and improve the differentiation of hepatic precursor cells. Nonetheless, miRNA-based approaches beyond cell generation have not yet entered preclinical or clinical investigations. Moreover, miRNA-based concepts for the biliary tree have yet to be developed. Further research on miRNA based modifications, however, holds the promise of enabling significant improvements to liver tissue engineering approaches due to their ability to regulate and fine-tune all biological processes relevant to hepatic tissue engineering, such as proliferation, differentiation, growth, and cell function.

Brain death and management of a potential organ donor in the intensive care unit

The concept of brain death developed with the advent of mechanical ventilation, and guidelines for determining brain death have been refined over time. Organ donation after brain death is a common source of transplant organs in Western countries. Early identification and notification of organ procurement organizations are essential. Management of potential organ donors must take into consideration specific pathophysiologic changes for medical optimization. Future aims in intensive and neurocritical care medicine must include reducing practice variability in the operational guidelines for brain death determination, as well as improving communication with families about the process of determining brain death.

Steroid Anti-Inflammatory Effects Did Not Improve Organ Quality in Brain-Dead Rats

Effect of glucocorticoid administration on improving the outcomes of kidney and liver allografts has not been clearly elucidated. This study investigated the effect of prednisolone administration after onset of brain death (BD) on kidney and liver in a controlled rat model of BD. BD was induced in rats by inflating an epidurally placed balloon catheter. Animals were treated with saline or prednisolone (5, 12.5, or 22.5 mg/kg) one hour after the onset of BD. After 4 hours of BD, experiments were terminated and serum and tissues were collected. Tissue gene and protein expression were measured for markers of inflammation, apoptosis, and cellular stress response markers. Prednisolone caused a reduction of plasma levels of IL-6, while the tissue expression of IL-6, IL-1β, and MCP-1 in both kidney and liver were also reduced. Creatinine plasma levels, complement (C3) expression, HSP-70, HO-1, Bcl2/BAX ratio, and PMN influx did not significantly change in kidney nor liver. Plasma AST and LDH levels were increased in the prednisolone treated group. Our results demonstrate prednisolone can has an anti-inflammatory effect mediated through reducing serum circulating cytokines. However, this anti-inflammatory effect does not translate into improved kidney function and indeed was associated with increased liver injury markers.

Anesthetic considerations in organ procurement surgery: a narrative review

PURPOSE

While a few publications specify the anesthetic implications of either brain or cardiac death, they lack detail on how to provide anesthesia during organ donation surgery. We provide a thorough description of important anesthetic considerations during organ donation surgery in patients with either brain or cardiac death.

SOURCE

A thorough literature review was undertaken to locate all relevant articles that describe systemic effects of brain and cardiac death and their anesthetic implications. We searched PubMed, Pubget, and EMBASE™ for relevant articles using the following search terms: anesthesia, management, donation cardiac death, donation brain death. In addition, we reviewed the relevant protocols at our own institution.

PRINCIPAL FINDINGS

Highly specific intraoperative management by an anesthesiologist is required during organ procurement after brain death. To manage the heart-beating brain-dead donor, the anesthesiologist must incorporate knowledge of the effects of brain death on each organ system as well as the effects of the preoperative measures that the donor required in the intensive care unit. It is also important to know which organs are going to be procured in order to establish specific goals and implement strategies (e.g., lung-protective ventilation or intraoperative glycemic control) to optimize donor outcome. During organ procurement after cardiac death, an anesthesiologist's direct involvement is particularly important for lung donors.

CONCLUSION

Anesthesiologist-guided physiological optimization of the brain-dead donor may be a factor in determining the outcome of the organ recipient. Additionally, anesthesiologists have an important role in helping to ensure that the highest quality and most appropriate care are rendered to non-heart-beating donors. This is achieved through establishing protocols in their hospitals for donation after cardiac death that maximize the number of available organs with the best chance for long-term graft viability.