Care of the potential organ donor

Victory out of tragedy: organ donation

Major improvements in trauma care during the last decade have improved survival rates in the severely injured. The unintended consequence is the presentation of patients with non-survivable injuries in a time frame in which intervention is considered and often employed due to prognostic uncertainty. In light of this, discerning survivability in these patients remains increasingly problematic. Evidence-based cut-points of futility can guide early decisions for discontinuing aggressive treatment and use of precious resources in severely injured patients arriving in extremis.

Management of potential cardiac donors

Heart transplantation (HTx) outcomes have improved with careful donor selection and management; nonetheless, donor shortages remain a major challenge. Optimizing donor management is crucial for improving donor utility rates and post-HTx outcomes. Brain death leads to various pathophysiological changes that can affect multiple organs, including the heart. Understanding these alterations and corresponding management strategies is key to optimizing the donor organ condition. This review assesses several aspects of these pathophysiological changes, including hemodynamic and endocrinological considerations, and emphasizes special consideration for potential cardiac donors, including serial echocardiographic evaluations for reversible cardiac dysfunction and coronary assessments for donors with risk factors.

Impact of Donor Hemodynamics on Recipient Survival in Heart Transplantation

BACKGROUND

Heart transplantation is the gold-standard therapy for end-stage heart failure, but rates of donor-heart use remain low due to various factors that are often not evidence based. The impact of donor hemodynamics obtained via right-heart catheterization on recipient survival remains unclear.

METHODS

The United Network for Organ Sharing registry was used to identify donors and recipients from September 1999-December 2019. Donor hemodynamics data were obtained and analyzed using univariate and multivariable logistical regression, with the primary endpoints being 1- and 5-year post-transplant survival.

RESULTS

Of the 85,333 donors who consented to heart transplantation during the study period, 6573 (7.7%) underwent right-heart catheterization, of whom 5531 eventually underwent procurement and transplantation. Donors were more likely to undergo right-heart catheterization if they had high-risk criteria. Recipients who had donor hemodynamic assessment had 1- and 5-year survival rates similar to those without donor hemodynamic assessment (87% vs 86%, 1 year). Abnormal hemodynamics were common in donor hearts but did not impact recipient survival rates, even when risk-adjusted in multivariable analysis.

CONCLUSIONS

Donors with abnormal hemodynamics may represent an opportunity to expand the pool of viable donor hearts.

Multiorgan recovery in a cadaver body using mild hypothermic ECMO treatment in a murine model

BACKGROUND

Transplant candidates on the waiting list are increasingly challenged by the lack of organs. Most of the organs can only be kept viable within very limited timeframes (e.g., mere 4-6 h for heart and lungs exposed to refrigeration temperatures ex vivo). Donation after circulatory death (DCD) using extracorporeal membrane oxygenation (ECMO) can significantly enlarge the donor pool, organ yield per donor, and shelf life. Nevertheless, clinical attempts to recover organs for transplantation after uncontrolled DCD are extremely complex and hardly reproducible. Therefore, as a preliminary strategy to fulfill this task, experimental protocols using feasible animal models are highly warranted. The primary aim of the study was to develop a model of ECMO-based cadaver organ recovery in mice. Our model mimics uncontrolled organ donation after an "out-of-hospital" sudden unexpected death with subsequent "in-hospital" cadaver management post-mortem. The secondary aim was to assess blood gas parameters, cardiac activity as well as overall organ state. The study protocol included post-mortem heparin-streptokinase administration 10 min after confirmed death induced by cervical dislocation under full anesthesia. After cannulation, veno-arterial ECMO (V-A ECMO) was started 1 h after death and continued for 2 h under mild hypothermic conditions followed by organ harvest. Pressure- and flow-controlled oxygenated blood-based reperfusion of a cadaver body was accompanied by blood gas analysis (BGA), electrocardiography, and histological evaluation of ischemia-reperfusion injury. For the first time, we designed and implemented, a not yet reported, miniaturized murine hemodialysis circuit for the treatment of severe hyperkalemia and metabolic acidosis post-mortem.

RESULTS

BGA parameters confirmed profound ischemia typical for cadavers and incompatible with normal physiology, including extremely low blood pH, profound negative base excess, and enormously high levels of lactate. Two hours after ECMO implantation, blood pH values of a cadaver body restored from < 6.5 to 7.3 ± 0.05, pCO2 was lowered from > 130 to 41.7 ± 10.5 mmHg, sO2, base excess, and HCO3 were all elevated from below detection thresholds to 99.5 ± 0.6%, - 4 ± 6.2 and 22.0 ± 6.0 mmol/L, respectively (Student T test, p < 0.05). A substantial decrease in hyperlactatemia (from > 20 to 10.5 ± 1.7 mmol/L) and hyperkalemia (from > 9 to 6.9 ± 1.0 mmol/L) was observed when hemodialysis was implemented. On balance, the first signs of regained heart activity appeared on average 10 min after ECMO initiation without cardioplegia or any inotropic and vasopressor support. This was followed by restoration of myocardial contractility with a heart rate of up to 200 beats per minute (bpm) as detected by an electrocardiogram (ECG). Histological examinations revealed no evidence of heart injury 3 h post-mortem, whereas shock-specific morphological changes relevant to acute death and consequent cardiac/circulatory arrest were observed in the lungs, liver, and kidney of both control and ECMO-treated cadaver mice.

CONCLUSIONS

Thus, our model represents a promising approach to facilitate studying perspectives of cadaveric multiorgan recovery for transplantation. Moreover, it opens new possibilities for cadaver organ treatment to extend and potentiate donation and, hence, contribute to solving the organ shortage dilemma.

Evaluation of red blood cell transfusion threshold in the management of brain-dead organ donors

The disparity between the demand and supply of organs has necessitated an expansion of the criteria for organ donation. Consequently, numerous guidelines have been proposed for managing brain-dead organ donors (BDODs) to improve their organ function and the organ procurement rate. Therefore, we aimed to evaluate the previously recommended threshold for red blood cell transfusion in BDODs. Medical records of BDODs were retrospectively reviewed from January 2012 to December 2021. We enrolled BDODs who stayed for more than 24 hours at an hospital organ procurement organization. We analyzed their organ function and the rate of organ procurement according to the hemoglobin concentration. A total of 111 BDODs were enrolled and divided into the following 2 groups: hemoglobin (Hb) ≥ 10 g/dL (45.0 %) and Hb < 10 g/dL (55.0 %). There were no significant differences between the groups in the total bilirubin, creatinine, arterial blood lactate, and the rate of organ procurement. A correlation analysis did not reveal any association between the hemoglobin concentration and organ function of the BDODs. Hemoglobin concentration of 10 g/dL cannot be considered a threshold for red blood cell transfusion. Furthermore, organ function is not correlated with a hemoglobin concentration > 7 g/dL. Restrictive transfusion strategy is appropriate for BDOD management.

Early prediction model of brain death in out-of-hospital cardiac arrest patients: a single-center retrospective and internal validation analysis

Background

A shortage of donor organs amid high demand for transplantable organs is a worldwide problem, and an increase in organ donation would be welcomed by the global healthcare system. Patients with brain death (BD) are potential organ donors, and early prediction of patients with BD may facilitate the process of organ procurement. Therefore, we developed a model for the early prediction of BD in patients who survived the initial phase of out-of-hospital cardiac arrest (OHCA).

Methods

We retrospectively analyzed data of patients aged < 80 years who experienced OHCA with a return of spontaneous circulation (ROSC) and were admitted to our hospital between 2006 and 2018. We categorized patients into either a non-BD or BD group. Demographic and laboratory data on ED admission were used for stepwise logistic regression analysis. Prediction scores of BD after OHCA were based on β-coefficients of prognostic factors identified in the multivariable logistic model.

Results

Overall, 419 OHCA patients with ROSC were admitted to our hospital during the study period. Seventy-seven patients showed BD (18.3%). Age and etiology of OHCA were significantly different between the groups. Logistic regression analysis confirmed that age, low-flow time, pH, and etiology were independent predictors of BD. The area under the receiver operating characteristic curve for this model was 0.831 (95% confidence interval, 0.786–0.876).

Conclusions

We developed and internally validated a new prediction model for BD after OHCA, which could aid in the early identification of potential organ donors for early donor organ procurement.

Effects of polyethylene glycol-20k IV solution on donor management in a canine model of donor brain death

BACKGROUND

Traditionally, vasopressors and crystalloids have been used to stabilize brain dead donors; however, the use of crystalloid is fraught with complications. This study aimed to investigate the effectiveness of a newly developed impermeant solution, polyethylene glycol-20k IV solution (PEG-20k) for resuscitation and support of brain dead organ donors.

METHODS

Brain death was induced in adult beagle dogs and a set volume of PEG-20k or crystalloid solution was given thereafter. The animals were then resuscitated over 16 h with vasopressors and crystalloid as necessary to maintain mean arterial pressure of 80-100 mmHg. The kidneys were procured and cold-stored for 24 h, after which they were analyzed using the isolated perfused kidney model.

RESULTS

The study group required significantly less crystalloid volume and vasopressors while having less urine output and requiring less potassium supplementation than the control group. Though the two groups' mean arterial pressure and lactate levels were comparable, the study group's kidneys showed less preservation injury after short-term reperfusion indexed by decreased lactate dehydrogenase release and higher creatinine clearance than the control group.

CONCLUSIONS

The use of polyethylene glycol-20k IV solution for resuscitating brain dead donors decreases cell swelling and improves intravascular volume, thereby improving end organ oxygen delivery before procurement and so preventing ischemia-reperfusion injury after transplantation.

Tacrolimus Prevents Mechanical and Humoral Alterations in Brain Death-Induced Lung Injury in Pigs

RATIONALE

Donor brain death-induced lung injury may compromise graft function after transplantation. Establishing strategies to attenuate lung damage remains a challenge because the underlying mechanisms remain uncertain.

OBJECTIVES

The effects of tacrolimus pretreatment were evaluated in an experimental model of brain death-induced lung injury.

METHODS

Brain death was induced by slow intracranial infusion of blood in anesthetized pigs after randomization to tacrolimus (orally administered at 0.25 mg. kg-1 BID the day before the experiment and intravenously at 0.05 mg. kg-1 one hour before the experiment; n=8) or placebo (n=9) pretreatment. Hemodynamic measurements were performed 1, 3, 5 and 7 hours after brain death. After euthanasia of the animals, lung tissue was sampled for pathobiological and histological analysis, including lung injury scoring (LIS).

MEASUREMENTS AND MAIN RESULTS

Tacrolimus pretreatment prevented increases in pulmonary artery pressure, pulmonary vascular resistance and pulmonary capillary pressure and decreases in systemic artery pressure and thermodilution cardiac output associated with brain death. After brain death, the ratio of the partial arterial O2 pressure to the inspired O2 fraction (PaO2/FiO2) decreased, which was prevented by tacrolimus. Tacrolimus pretreatment prevented increases in the interleukin (IL)-6-to-IL-10 ratio, vascular cell adhesion molecule-1, circulating levels of IL-1β, IL-6-to-IL-10 ratio and glycocalyx-derived molecules. Tacrolimus partially decreased apoptosis [Bax-to-Bcl2 ratio (p=0.07) and the number of apoptotic cells in the lungs (p<0.05)] but failed to improve LIS.

CONCLUSIONS

Immunomodulation through tacrolimus pretreatment prevented pulmonary capillary hypertension as well as the activation of inflammatory and apoptotic processes in the lungs after brain death; however, LIS did not improve.

Heads, Bodies, Brains, and Selves: Personal Identity and the Ethics of Whole-Body Transplantation

Plans to attempt what has been called a head transplant, a body transplant, and a head-to-body transplant in human beings raise numerous ethical, social, and legal questions, including the circumstances, if any, under which it would be ethically permissible to attempt whole-body transplantation (WBT) in human beings, the possible effect of WBT on family relationships, and how families should shape WBT decisions. Our assessment of many of these questions depends partially on how we respond to sometimes centuries-old philosophical thought experiments about personal identity. As with so much in bioethics, it is impossible to escape, or at least inadvisable to try to bypass, the relevant foundational philosophical concerns.

First clinical-grade porcine kidney xenotransplant using a human decedent model

A radical solution is needed for the organ supply crisis, and the domestic pig is a promising organ source. In preparation for a clinical trial of xenotransplantation, we developed an in vivo pre-clinical human model to test safety and feasibility tenets established in animal models. After performance of a novel, prospective compatible crossmatch, we performed bilateral native nephrectomies in a human brain-dead decedent and subsequently transplanted two kidneys from a pig genetically engineered for human xenotransplantation. The decedent was hemodynamically stable through reperfusion, and vascular integrity was maintained despite the exposure of the xenografts to human blood pressure. No hyperacute rejection was observed, and the kidneys remained viable until termination 74 h later. No chimerism or transmission of porcine retroviruses was detected. Longitudinal biopsies revealed thrombotic microangiopathy that did not progress in severity, without evidence of cellular rejection or deposition of antibody or complement proteins. Although the xenografts produced variable amounts of urine, creatinine clearance did not recover. Whether renal recovery was impacted by the milieu of brain death and/or microvascular injury remains unknown. In summary, our study suggests that major barriers to human xenotransplantation have been surmounted and identifies where new knowledge is needed to optimize xenotransplantation outcomes in humans.

Primary Graft Dysfunction after Heart Transplantation - Unravelling the Enigma

Primary graft dysfunction (PGD) remains the main cause of early mortality following heart transplantation despite several advances in donor preservation techniques and therapeutic strategies for PGD. With that aim of establishing the aetiopathogenesis of PGD and the preferred management strategies, the new consensus definition has paved the way for multiple contemporaneous studies to be undertaken and accurately compared. This review aims to provide a broad-based understanding of the pathophysiology, clinical presentation and management of PGD.

Systematic review on potential brain dead donor estimations and conversion rates to actually realized organ donations

INTRODUCTION

Accurate estimations of potential organ donors (POTDs) are required to improve transplant systems. This systematic review analyses current studies on national estimations of potential donors for transplantation as well as the practical and policy implications of detected differences.

METHOD

A systematic review of literature published between 01.01.2010 and 01.04.2020 in PubMed was conducted. Data was extracted into a self-developed matrix, and further data retrieved on national population sizes, waiting lists and transplant activities.

RESULTS

Six studies were included. Investigated populations, underlying data collections and eligibility criteria for POTDs varied widely. Estimated POTDs per million population (p.m.p.) ranged from 25.8 to 333.6, conversion rates from 3.2% to 47.5% leading to 41.2 to 86.4 transplanted organs p.m.p.. Patients on the waiting lists varied from 66.7 to 338.9 p.m.p., defining gaps between organ supply and demand in countries. Not all studies adhered to the definitions and processes of the critical pathway for deceased donation which is the latest international consensus statement on deceased organ donation.

CONCLUSION

Differences in estimated POTDs and differences in supply and demand of donor organs between countries cannot be satisfactorily explained yet due to an obvious lack of evidence, consistent methodology, international consensus and robust underlying datasets. Future studies should be based on robust underlying data sets and aim for potential donor estimations that allow national comparisons due to the adherence to the international consensus on definitions, processes and methodology.

Brain death and management of the potential donor

One of the first attempts to define brain death (BD) dates from 1963, and since then, the diagnosis criteria of that entity have evolved. In spite of the publication of practice parameters and evidence-based guidelines, BD is still causing concern and controversies in the society. The difficulties in determining brain death and making it understood by family members not only endorse futile therapies and increase health care costs, but also hinder the organ transplantation process. This review aims to give an overview about the definition of BD, causes, physiopathology, diagnosis criteria, and management of the potential brain-dead donor. It is important to note that the BD determination criteria detailed here follow the AAN’s recommendations, but the standard practice for BD diagnosis varies from one country to another.

Deceased Organ Transplantation in Bangladesh: The Dynamics of Bioethics, Religion and Culture

Organ transplantation from living related donors in Bangladesh first began in October 1982, and became commonplace in 1988. Cornea transplantation from posthumous donors began in 1984 and living related liver and bone marrow donor transplantation began in 2010 and 2014 respectively. The Human Organ Transplantation Act officially came into effect in Bangladesh on 13th April 1999, allowing organ donation from both brain-dead and related living donors for transplantation. Before the legislation, religious leaders issued fatwa, or religious rulings, in favor of organ transplantation. The Act was amended by the Parliament on 8th January, 2018 with the changes coming into effect shortly afterwards on 28th January. However, aside from a few posthumous corneal donations, transplantation of vital organs, such as the kidney, liver, heart, pancreas, and other body parts or organs from deceased donors, has remained absent in Bangladesh. The major question addressed in this article is why the transplantation of vital organs from deceased donors is absent in Bangladesh. In addition to the collection of secondary documents, interviews were conducted with senior transplant physicians, patients and their relatives, and the public, to learn about posthumous organ donation for transplantation. Interviews were also conducted with a medical student and two grief counselors to understand the process of counseling the families and obtaining consent to obtain posthumous cornea donations from brain-dead patients. An interview was conducted with a professional anatomist to understand the processes behind body donation for the purposes of medical study and research. Their narrative reveals that transplant physicians may be reticent to declare brain death as the stipulations of the 1999 act were unclear and vague. This study finds that Bangladeshis have strong family ties and experience anxiety around permitting separating body parts of dead relatives for organ donation for transplantation, or donating the dead body for medical study and research purposes. Posthumous organ donation for transplantation is commonly viewed as a wrong deed from a religious point of view. Religious scholars who have been consulted by the government have approved posthumous organ donation for transplantation on the grounds of necessity to save lives even though violating the human body is generally forbidden in Islam. An assessment of the dynamics of biomedicine, religion and culture leads to the conclusion that barriers to posthumous organ donation for transplantation that are perceived to be religious may actually stem from cultural attitudes. The interplay of faith, belief, religion, social norms, rituals and wider cultural attitudes with biomedicine and posthumous organ donation and transplantation is very complex. Although overcoming the barriers to organ donation for transplantation is challenging, initiation of transplantation of vital organs from deceased donors is necessary within Bangladesh. This will ensure improved healthcare outcomes, prevent poor people from being coerced into selling their organs to rich recipients, and protect the solidarity and progeny of Bangladeshi families.

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.

Review 1: Lung transplant-from donor selection to graft preparation

For various end-stage lung diseases, lung transplantation remains one of the only viable treatment options. While the demand for lung transplantation has steadily risen over the last few decades, the availability of donor grafts is limited, which have resulted in progressively longer waiting lists. In the early years of lung transplantation, only the 'ideal' donor grafts are considered for transplantation. Due to the donor shortages, there is ongoing discussion about the safe use of 'suboptimal' grafts to expand the donor pool. In this review, we will discuss the considerations around donor selection, donor-recipient matching, graft preparation and graft optimisation.

EGF-GH Axis in Rat Steatotic and Non-steatotic Liver Transplantation From Brain-dead Donors

BACKGROUND

We evaluated the potential dysfunction caused by changes in growth hormone (GH) levels after brain death (BD), and the effects of modulating GH through exogenous epidermal growth factor (EGF) in steatotic and nonsteatotic grafts.

METHODS

Steatotic and nonsteatotic grafts from non-BD and BD rat donors were cold stored for 6 hours and transplanted to live rats. Administration of GH and EGF and their underlying mechanisms were characterized in recipients of steatotic and nonsteatotic grafts from BD donors maintained normotensive during the 6 hours before donation. Circulating and hepatic GH and EGF levels, hepatic damage, and regeneration parameters were evaluated. Recipient survival was monitored for 14 days. Somatostatin, ghrelin, and GH-releasing hormones that regulate GH secretion from the anterior pituitary were determined. The survival signaling pathway phosphoinositide-3-kinase/protein kinase B that regulates inflammation (suppressors of cytokine signaling, high-mobility group protein B1, oxidative stress, and neutrophil accumulation) was evaluated.

RESULTS

BD reduced circulating GH and increased GH levels only in steatotic livers. GH administration exacerbated adverse BD-associated effects in both types of graft. Exogenous EGF reduced GH in steatotic livers, thus activating cell proliferation and survival signaling pathways, ultimately reducing injury and inflammation. However, EGF increased GH in nonsteatotic grafts, which exacerbated damage. The benefits of EGF for steatotic grafts were associated with increased levels of somatostatin, a GH inhibitor, whereas the deleterious effect on nonsteatotic grafts was exerted through increased amounts of ghrelin, a GH stimulator.

CONCLUSIONS

GH treatment is not appropriate in rat liver transplant from BD donors, whereas EGF (throughout GH inhibition) protects only in steatotic grafts.

Liver Steatosis in Brain-Dead Donors: Progression Pattern and Affecting Factors

OBJECTIVES

No study has investigated the short-term effect of acute insulin resistance on liver steatosis in critically ill condition. We analyzed the effects of critically ill conditions of brain-dead donors (BDDs) on the development and progression of liver steatosis to investigate the influencing factors.

METHODS

This study was conducted retrospectively between January 2003 and December 2017. BDDs were for organ procurement. BDDs with body mass indexes (BMIs) < 18.5 kg/m² and ≥ 30 kg/m² were excluded. Liver steatosis was defined as ≥5% of the fat vacuole. The serum glucose level (SGL) was used to reflect insulin resistance.

RESULTS

Of the 179 BDDs, 87 (48.6%) had liver steatosis. BMI (r = 0.176, P = .019) and SGL (r = 0.267, P < .001) were correlated with steatosis. The length of the predonation period (LPDP) was negatively correlated with steatosis (r = -0.379, P < .001). BMI (odds ratio 1.266, P = .002), SGL ≥180 mg/dL (odds ratio 2.825, P = .003), and LPDP (odds ratio 0.885, P = .001) were independent risk factors for liver steatosis.

CONCLUSION

Liver steatosis is related to the SGL and BMI. Liver steatosis develops acutely in the early phase of critical illness and patients recover gradually.

Renal Procurement: Techniques for Optimizing the Quality of the Graft in the Cadaveric Setting

PURPOSE OF REVIEW

Kidney transplantation is the best treatment for end-stage renal disease. However, due to organ shortage, suboptimal grafts are increasingly being used.

RECENT FINDINGS

We carried out a review on the methods and techniques of organ optimization in the cadaveric setting. Donor care is the first link in a chain of care. Right after brain death, there is a set of changes, of which hormonal and hemodynamic changes are the most relevant. Several studies have been conducted to determine which drugs to administer, although in most cases, the results are not definitive. The main goal seems rather achieve a set of biochemical and hemodynamic objectives. The ischemia-reperfusion injury is a critical factor for kidney damage in transplantation. One of the ways found to deal with this type of injury is preconditioning. Local and remote ischemic preconditioning has been studied for various organs, but studies on the kidney are scarce. A new promising area is pharmacological preconditioning, which is taking its first steps. Main surgical techniques were established in the late twentieth century. Some minor new features have been introduced to deal with anatomical variations or the emergence of donation after circulatory death. Finally, after harvesting, it is necessary to ensure the best conditions for the kidneys until the time of transplantation. Much has evolved since static cold preservation, but the best preservation conditions are yet to be determined. Conservation in the cold has come to be questioned, and great results have appeared at temperatures closer to physiological.

A stroke volume-based fluid resuscitation protocol decreases vasopressor support and may increase organ yield in brain-dead donors

Brain-dead donors are frequently hypovolemic and hypotensive requiring vasopressor support. We studied a stroke volume-based fluid resuscitation and vasopressor weaning protocol prospectively on 64 hypotensive donors, with a recent control cohort of 30 hypotensive donors treated without a protocol. Stroke volume was measured every 30 minutes for 4 hours by pulse contour analysis or esophageal Doppler. A 500 mL saline fluid bolus was infused over 30 minutes and repeated if the stroke volume increased by 10%. No fluid was infused if the stroke volume did not increase by 10%. Vasopressors were weaned every 10 minutes if the mean arterial pressure was greater than 65 mm Hg. The protocol group received 1937 ± 906 mL fluid compared to 1323 ± 919 mL in the control group (P = .003). Mean time on vasopressors was decreased from 957.6 ± 586.2 to 176.3 ± 82.2 minutes (P<.001). Donors in the protocol group were more likely to donate four or more organs than donors in the control group (OR = 4.114, 95% Confidence Interval (CI) = 1.003-16.876). While more organs were transplanted per donor in the protocol group (3.39 ± 1.52) than in the control group (2.93 ± 1.44) (P = .268), the difference did not reach statistical significance. A goal-directed fluid resuscitation protocol decreased organ ischemia and may increase organs transplanted.

Comorbidities and Age in Brain-Dead Donors and Liver Transplantation: A 15-Year Retrospective Investigation

OBJECTIVES

Although livers from older donors (> 70 y) have been shown to be increasingly more efficiently used for transplant, donor comorbidities are considered additional risk factors. This is quite intriguing as comorbidities are known to increase with advancing age in the donor population.

MATERIALS AND METHODS

We assessed whether age and donor comorbidities influenced liver procurement over a 15-year period in a cohort of 1702 brain-dead donors in Tuscany, Italy.

RESULTS

Over the study period, age of potential donors significantly increased (P = .02) as well as the proportion of patients who were > 55 years old. The incidence of hypertension, diabetes mellitus, and previously known coronary artery disease also significantly increased. We observed a progressive increase in the number of transplanted livers from donors with advancing age despite an increase in comorbidities. The highest incidences of traumatic brain injury and anoxic brain injury were observed in the youngest donors. Transaminase levels and use of vasoactive drugs were lower in donors who were ≥ 72 years old.

CONCLUSIONS

According to our results, criteria for liver donors have already changed. Although age does not seem to be a limiting factor, older donors deserve a more accurate donor selection due to the higher incidence of risk factors (primarily diabetes mellitus).

Primary graft dysfunction after heart transplantation: a thorn amongst the roses

Primary graft dysfunction (PGD) remains the leading cause of early mortality post-heart transplantation. Despite improvements in mechanical circulatory support and critical care measures, the rate of PGD remains significant. A recent consensus statement by the International Society of Heart and Lung Transplantation (ISHLT) has formulated a definition for PGD. Five years on, we look at current concepts and future directions of PGD in the current era of transplantation.

Underutilization of potential donors for lung transplantation at a tertiary care center in North India

Objective:

Lung transplantation is infrequently performed in India due to several constraints, and whether the poor lung transplantation rates in India are due to a lack of eligible lung donors is unclear. In this study, we explored the availability of donors for lung transplantation.

Materials and Methods:

This was a retrospective analysis of all brain-dead participants who underwent assessment of eligibility for lung donation between August 2015 and June 2018. All participants underwent a detailed clinical evaluation that included history, physical examination, arterial blood gas analysis, chest radiograph, and bronchoscopy. The final eligibility for lung donation was assessed using the existing “ideal” criteria and the less stringent “extended” criteria.

Results:

A total of 55 brain-dead participants (41 [74.5%] males) were assessed for eligibility for lung donation. The mean (standard deviation [SD]) age of the participants was 38.4 (17.2) years. The mean (SD) duration of prior invasive mechanical ventilation at the time of assessment was 4 (3.1) days, with a mean (SD) partial pressure of arterial oxygen: inspired oxygen fraction ratio (PaO₂:FiO₂) of 326.6 (153.5). The proportion of participants who were found suitable for lung donation was 16 (29.1%) and 35 (63.6%) on employing the ideal and the extended criteria, respectively. Inadequate oxygenation status, abnormal chest radiograph, and sepsis were the most common reasons for excluding participants using either criteria. Despite the availability of adequate lung donors, only one lung transplantation could be performed.

Conclusion:

Even with the most stringent criteria for lung assessment, nearly one-third of the brain-dead participants had lungs suitable for lung transplantation. Lack of eligible lung donors is not a reason for the poor lung transplantation rates in India.

Management of the Pediatric Organ Donor

Management of the pediatric organ donor necessitates understanding the physiologic changes that occur preceding and after death determination. Recognizing these changes allows application of the therapeutic strategies designed to optimize hemodynamics and metabolic state to allow for preservation of end-organ function for maximal organ recovery and minimal damage to the donor grafts. The pediatric pharmacist serves as the medication expert and may collaborate with the organ procurement organizations for provision of pharmacologic hemodynamic support, hormone replacement therapy, antimicrobials, and nutrition for the pediatric organ donor.

Summary of Spanish recommendations on intensive care to facilitate organ donation

With the aim of consolidating recommendations about the practice of initiating or continuing intensive care to facilitate organ donation (ICOD), an ad hoc working group was established, comprising 10 intensivists designated by the Spanish Society of Intensive Care and Coronary Units (SEMICYUC) and the Spanish National Transplant Organization (ONT). Consensus was reached in all recommendations through a deliberative process. After a public consultation, the final recommendations were institutionally adopted by SEMICYUC, ONT, and the Transplant Committee of the National Health-Care System. This article reports on the resulting recommendations on ICOD for patients with a devastating brain injury for whom the decision has been made not to apply any medical or surgical treatment with a curative purpose on the grounds of futility. Emphasis is made on the systematic referral of these patients to donor coordinators, the proper assessment of the likelihood of brain death and medical suitability, and on transparency in communication with the patient's family. The legal and ethical aspects of ICOD are addressed. ICOD is considered a legitimate practice that offers more patients the opportunity of donating their organs upon their death and helps to increase the availability of organs for transplantation.

Impact of Donor Core Body Temperature on Graft Survival After Heart Transplantation

BACKGROUND

A previous donor intervention trial found that induction of mild therapeutic hypothermia in the brain-dead donor reduced the dialysis requirement after kidney transplantation. Consequences on the performance of cardiac allografts after transplantation were not explored to date.

METHODS

Cohort study investigating 3-year heart allograft survival according to spontaneous core body temperature (CBT) assessed on the day of organ procurement. The study is nested in the database of the randomized trial of donor pretreatment with low-dose dopamine (ClinicalTrials.gov identifier: NCT000115115).

RESULTS

Ninety-nine heart transplant recipients who had received a cardiac allograft from a multiorgan donor enrolled in the dopamine trial were grouped by tertiles of the donor's CBT assessed by a mere temperature reading 4 to 20 hours before procurement (lowest, 32.0-36.2°C; middle, 36.3-36.8°C; highest, 36.9-38.8°C). Baseline characteristics considering demographics of donors and recipients, concomitant donor treatments, donor hemodynamic, and respiratory parameters as well as underlying cardiac diseases in recipients, pretransplant hemodynamic assessments, including pretransplant inotropic/mechanical support, urgency, and waiting time were similar. A lower CBT was associated with inferior heart allograft survival (hazard ratio, 0.53; 95% confidence interval, 0.31-0.93, per tertile; P = 0.02, and hazard ratio, 0.68; 95% confidence interval, 0.50-0.93°C; P = 0.02) when CBT was included as continuous explanatory variable in the Cox regression analysis.

CONCLUSIONS

A lower CBT in the brain-dead donor before procurement may associate with an unfavorable clinical course after heart transplantation. More research is required, before therapeutic hypothermia can routinely be used in multiorgan donors when a cardiac transplantation is intended.

Successful transplantation of kidneys from deceased donors with terminal acute kidney injury

BACKGROUND

There are many doubts with regards to accepting deceased kidneys with acute kidney injury (AKI) for transplantation.

PURPOSE

The aim of this study was to present the 5-years outcome of kidney transplantation cases where deceased donors developed AKI before organ procurement.

METHODS

Two hundred twenty-six deceased renal transplants were analyzed. Data regarding donors and recipients were collected. Terminal AKI was defined as terminal serum creatinine concentration higher than 1.99 mg/dL and 66 such cases were diagnosed. All kidney transplant recipients were followed for 60 months.

RESULTS

AKI group presented more episodes of delayed graft function (DGF) compared to the non-AKI group (56% vs 35%, p < .05). No differences were observed between the groups in the rate of acute rejection episodes, kidney function as well as patient and graft survival.

CONCLUSIONS

Transplants with AKI present more often DGF and comparable graft survival to transplants without AKI. Kidneys with AKI can be a valuable source of organs provided attentive selection and appropriate care of deceased donors.

Neuroinflammation induced by lipopolysaccharide causes cognitive impairment in mice

In this study, we investigated lipopolysaccharide (LPS)-induced cognitive impairment and neuroinflammation in C57BL/6J mice by using behavioral tests, immunofluorescence, enzyme-linked immunosorbent assay (ELISA) and Western blot. We found that LPS treatment leads to sickness behavior and cognitive impairment in mice as shown in the Morris water maze and passive avoidance test, and these effects were accompanied by microglia activation (labeled by ionized calcium binding adaptor molecule-1, IBA-1) and neuronal cell loss (labeled by microtubule-associated protein 2, MAP-2) in the hippocampus. The levels of interleukin-4 (IL-4) and interleukin-10 (IL-10) in the serum and brain homogenates were reduced by the LPS treatment, while the levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), prostaglandin E2 (PGE2) and nitric oxide (NO) were increased. In addition, LPS promoted the expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in the brain homogenates. The Western blot analysis showed that the nuclear factor kappa B (NF-κB) signaling pathway was activated in the LPS groups. Furthermore, VIPER, which is a TLR-4-specific inhibitory peptide, prevented the LPS-induced neuroinflammation and cognitive impairment. These data suggest that LPS induced cognitive impairment and neuroinflammation via microglia activation by activating the NF-kB signaling pathway; furthermore, we compared the time points, doses, methods and outcomes of LPS administration between intraperitoneal and intracerebroventricular injections of LPS in LPS-induced neuroinflammation and cognitive impairment, and these data may provide additional insight for researchers performing neuroinflammation research.

Epidemiological changes in potential heart donors after brain death: a retrospective 15 year cohort study

Changes in the causes of brain death may influence the numbers of hearts that can be procured and transplanted. We retrospectively investigated whether the distribution of causes responsible for brain death have changed over a 15-year period in a cohort of 1286 potential heart donor (aged ≤ 60), and whether it influenced heart procurement. Between 2001 and 2016, the age of potential donors significantly increased (p < 0.0001) as well as the relative proportion of postanoxic brain death, while that of traumatic brain injury decreased (p = 0.0007). A significant increase in the use of norepinephrine was detectable. The number of transplanted hearts did not significantly change, with no differences in the age of donors or in the causes of brain death. According to our data, in our 15-year study period, significant changes in the causes of brain death occurred (indicated by a reduction in potential donors following traumatic brain injury) together with an increase in donor age. Nevertheless, the number of transplanted hearts did not change probably thanks to a modified donor management (as inferred by a different use of vasoactive drugs).

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.

Role of Methylprednisolone in the Management of Hemodynamically Unstable Brain-Dead Cases

OBJECTIVES

Optimal care of potential donors can lead to successful transplantation. Hemodynamic instability is a common complication in deceased potential donors. The most common underlying causes are hormonal and electrolyte disturbances as well as a hyperinflammatory state, which is rooted in activation of the cytokine cascade. In this study, our aim was to evaluate the efficacy of methylprednisolone injection, an agent introduced for inflammation suppression to achieve more stability in cases of hemodynamic disturbances.

MATERIALS AND METHODS

This study covered the period from April 2016 to June 2017 and included 45 randomly selected hemodynamically unstable brain-dead cases (mean arterial pressure < 60 mm Hg). For these cases, primary management included trying to achieve stability; however, after many hours, we experienced hemodynamic instability again. Because of no other correctable methods, we decided to use methylprednisolone injection. The potential deceased donors received a total of 1 g methylprednisolone in two 500-mg divided doses after transfer to the organ procurement unit.

RESULTS

Of 45 patients, 26 were male (58%), and the mean age of patients was 33 years. The most common causes of brain death were trauma (33%) and cerebrovascular accident (22%). Systolic and diastolic blood pressures increased significantly after methylprednisolone use. We observed no significant dif ferences in pulse rate. In addition, methylprednisolone could correct pH from 7.33 ± 0.11 to 7.38 ± 0.12 (P = .007).

CONCLUSIONS

Use of methylprednisolone in hemodynamically unstable deceased donors could allow better management of these cases. Because there are various factors such as infusion of vasopressor drugs or fluid therapy that could affect the hemodynamic status of these cases, future studies with larger sample sizes are recommended to control these confounding factors.

Donor Dopamine Does Not Affect Liver Graft Survival: Evidence of Safety From a Randomized Controlled Trial

Treatment of donation after brain death (DBD) donors with low-dose dopamine improves the outcomes after kidney and heart transplantation. This study investigates the course of liver allografts from multiorgan donors enrolled in the randomized dopamine trial between 2004 and 2007 (clinicaltrials.gov identifier: NCT00115115). There were 264 hemodynamically stable DBDs who were randomly assigned to receive low-dose dopamine. Dopamine was infused at 4 μg/kg/minute for a median duration of 6.0 hours (interquartile range, 4.4-7.5 hours). We assessed the outcomes of 212 liver transplantations (LTs) performed at 32 European centers. Donors and recipients of both groups were very similar in baseline characteristics. Pretransplant laboratory Model for End-Stage Liver Disease score was not different in recipients of a dopamine-treated versus untreated graft (18 ± 8 versus 20 ± 8; P = 0.12). Mean cold ischemia time was 10.6 ± 2.9 versus 10.1 ± 2.8 hours (P = 0.24). No differences occurred in biopsy-proven rejection episodes (14.4% versus 15.7%; P = 0.85), requirement of hemofiltration (27.9% versus 31.5%; P = 0.65), the need for early retransplantation (5.8% versus 6.5%; P > 0.99), the incidence of primary nonfunction (7.7% versus 8.3%; P > 0.99), and in-hospital mortality (15.4% versus 14.8%; P > 0.99). Graft survival was 71.2% versus 73.2% and 59.6% versus 62.0% at 2 and 3 years (log-rank P = 0.71). Patient survival was 76.0% versus 78.7% and 65.4% versus 69.4% at 1 and 3 years (log-rank P = 0.50). In conclusion, donor pretreatment with dopamine has no short-term or longterm effects on outcome after LT. Therefore, low-dose dopamine pretreatment can safely be implemented as the standard of care in hemodynamically stable DBDs.

Patient, caregiver and physician perspectives on participating in a thoracic rapid tissue donation program

OBJECTIVE

The collection of posthumous tissue from advanced stage lung cancer patients is beneficial to medical science. Recruiting living patients to a Rapid Tissue Donation Program (RTD) poses several psychosocial challenges and little is known about perceptions of joining this type of program. This study qualitatively examined perceptions of advanced stage lung cancer patients (n=14) participating in a lung cancer RTD program, their NoK (n=11), and physicians (n=6) at the Thoracic Oncology Clinic at H. Lee Moffitt Cancer Center & Research Institute, Tampa, Florida USA.

METHODS

Semi-structured interviews were conducted with participants and interview transcripts were analyzed using the constant comparison method.

RESULTS

Majority of patients joined to give back to research, discussed participation with family members, and desired for family to receive information about the use of the tissue after their death. All participating NoK were supportive of their family member's decision. Physicians described the program as running smoothly, but provided suggestions for process improvements.

CONCLUSION

Participants joined with intention to give back to research community and families were supportive of loved one's participation in RTD. Physicians agreed with overall process.

PRACTICE IMPLICATIONS

Key factors for a successful RTD program is tailoring to institutional and individual needs.

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.