Organ Donation, the Non-Perfect Lung Donor, and Variability in Conversion to Transplant

Rates of lung donation have increased over the past several years. This has been accomplished through the utilization of donors with extended criteria, the creation of donor hospitals or centers, and the optimization of lungs through the implementation of donor management protocols. These measures have resulted in augmenting the pool of available donors thereby decreasing the wait time for lung transplantation candidates. Although transplant programs vary significantly in their acceptance rates of these organs, studies have not shown any difference in the incidence of primary graft dysfunction or overall mortality for the recipient when higher match-run sequence organs are accepted. Yet, the level of comfort in accepting these donors varies among transplant programs. This deviation in practice results in these organs going to lower-priority candidates thereby increasing the waitlist time of other recipients and ultimately has a deleterious effect on an institution's waitlist mortality.

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.

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.

Lung Ultrasound Assisted Comparison of Volume Effects of Fluid Replacement Regimens in Pediatric Patients Undergoing Penile Hypospadias Repair: A Randomized Controlled Trial

Background

Effective perioperative fluid therapy is a great consideration.

Objectives

Using lung ultrasound (LUS), this study evaluated the preference of the conventional and restrictive fluid replacement regimens for their volume impact in pediatric patients undergoing a relatively long procedure with limited volume loss (hypospadias repair).

Methods

Eighty pediatric patients scheduled for hypospadias repair surgery were enrolled for conventional (CG) or restrictive fluid management groups (RG). The CG obtained Ringer's lactate at the conventional calculated doses, while the RG obtained infusion of Ringer's lactate at a rate of 3 mL/kg/h. B-line numbers in the LUS, recovery score, urine output, blood pressure (BP), heart rate HR, and oxygen saturation (SpO₂) were recorded.

Results

As evidenced by the LUS, RG showed a higher incidence of normal lung morphology with a mean and SD of 1.3 ± 2.2 for B-line numbers, whereas, in CG, they were 3.1 ± 2.2 with a P-value < 0.001. Urine output was 3.2 ± 0.8 and 2.9 ± 0.7 for CG and RG, respectively, with a P-value equal to 0.07. HR, BP, and SpO₂ differences between groups were statistically insignificant. The recovery score was higher in RG (5.8 ± 0.4) than in CG (5.1 ± 0.8) at the first postoperative 20 minutes, with a P-value < 0.001.

Conclusions

In lengthy procedures with limited volume loss, using a moderately restrictive regimen is preferred over the conventional intraoperative fluid regimen considering both respiratory dysfunctions and recovery score.

Management of the brain-dead organ donor

Organ transplantation is a life-saving intervention for patients suffering from end-stage organ failure, but it relies on the availability of donor organs. However, even when donors are available, the brain-dead organ donor is a clinically complex patient who presents many management challenges. Donor management with a goal of optimization of organ function is essential to maximizing the number of patients who can be helped by each individual donor. Thoughtful critical care management of the potential organ donor, with a focus on meeting donor management goals, can lead to improved donation outcomes.

The Low Utilization Rate of Donor Lungs in China: A Single-Center Experience

BACKGROUND Despite the increasing number of organ donations, the utilization rate of donor lungs in China is much lower than that in many other countries. MATERIAL AND METHODS The donor lungs were evaluated before departure (stage 1), after on-site management (stage 2), and after harvesting (stage 3). Variables of donor lungs from medical institutions with lung transplant qualification (group A) and those without qualification (group B) were compared. The outcome measurements for lung recipients were early survival and primary graft dysfunction. RESULTS Among the 277 donor lungs, 140 (51%) were suitable for transplantation and 101 were sent to our institution for 62 single-lung transplantations and 50 double-lung transplantations. The acceptability rates at stage 1, stage 2, and stage 3 were 78%, 56%, and 51%, respectively. In addition, 69 (50.4%) donor lungs were abandoned for poor quality related to management, 24 (17.5%) for no adequate recipients, 15 (10.9%) for family refusal, 14 (10.2%) for organ procurement organization-related reasons, and 15 (10.9%) for other reasons. Donors in group A were ventilated longer and had longer ischemic time than those in group B. However, bronchoscopy, imaging, and oxygenation in group A achieved better results than in group B. No between-group difference in 30-day mortality or rate of grade 3 primary graft dysfunction was observed. CONCLUSIONS Problems at supply and demand ends contribute to the low utilization rate of donor lungs in China. The poor management of donor lungs and the short waiting list for lung transplantation are major reasons.

The impact of neurologically deceased donors' blood pressures on clinical outcomes in transplant recipients: a systematic review

PURPOSE

We performed a systematic review of the literature to identify the ideal blood pressure (BP) target in neurologically deceased organ donors to optimize outcomes of recipient organ function and survival, and organs transplanted per donor.

SOURCE

We searched MEDLINE and EMBASE from inception to December 2018 for studies that evaluated BP targets in neurologically deceased organ donors. A two-step review process with three independent reviewers was employed. We assessed the risk of bias and applied Grading of Recommendations Assessment, Development, and Evaluation methodology to evaluate the certainty of the evidence by outcome.

PRINCIPAL FINDINGS

Twelve cohort studies were included in our final analysis. Seven studies showed that hypotension was associated with worse post-transplant graft function or survival, while three studies found no association between hypotension and post-transplant graft function or survival. Two other studies showed no association between hypotension and organs transplanted per donor. Overall, six of the identified studies had serious risk of bias.

CONCLUSION

A systolic BP less 90 mmHg may be associated with graft dysfunction in kidney recipients, but this is based on very low certainty in evidence. Although an ideal and universal BP target in neurologically deceased organ donors is not clearly identifiable in the literature, this could reflect the complexity of donor hemodynamics and the need for individualized targets for different organs. Further prospective research is required to address these questions.

Goal-Directed Fluid Therapy Does Not Improve Early Glomerular Filtration Rate in a Porcine Renal Transplantation Model

BACKGROUND:

Insufficient fluid administration intra- and postoperatively may lead to delayed renal graft function (DGF), while fluid overload increases the risk of heart failure, infection, and obstipation. Several different fluid protocols have been suggested to ensure optimal fluid state. However, there is a lack of evidence of the clinical impact of these regimens. This study aimed to determine whether individualized goal-directed fluid therapy (IGDT) positively affects the initial renal function compared to a high-volume fluid therapy (HVFT) and to examine the effects on renal endothelial glycocalyx, inflammatory and oxidative stress markers, and medullary tissue oxygenation. The hypothesis was that IGDT improves early glomerular filtration rate (GFR) in pigs subjected to renal transplantation.

METHODS:

This was an experimental randomized study. Using a porcine renal transplantation model, animals were randomly assigned to receive IGDT or HVFT during and until 1 hour after transplantation from brain-dead donors. The kidneys were exposed to 18 hours of cold ischemia. The recipients were observed until 10 hours after reperfusion, which included GFR measured as clearance of chrom-51-ethylendiamintetraacetat (⁵¹Cr-EDTA), animal weight, and renal tissue oxygenation by fiber optic probes. The renal expression of inflammatory and oxidative stress markers as well as glomerular endothelial glycocalyx were analyzed in the graft using polymerase chain reaction (PCR) technique and immunofluorescence.

RESULTS:

Twenty-eight recipient pigs were included for analysis. We found no evidence that IGDT improved early GFR compared to HVFT (P = .45), while animal weight increased more in the HVFT group (a mean difference of 3.4 kg [1.96–4.90]; P < .0001). A better, however nonsignificant, preservation of glomerular glycocalyx (P = .098) and significantly lower levels of the inflammatory marker cyclooxygenase 2 (COX-2) was observed in the IGDT group when compared to HVFT. COX-2 was 1.94 (1.50–2.39; P = .012) times greater in the HVFT group when compared to the IGDT group. No differences were observed in outer medullary tissue oxygenation or oxidative stress markers.

CONCLUSIONS:

IGDT did not improve early GFR; however, it may reduce tissue inflammation and could possibly lead to preservation of the glycocalyx compared to HVFT.

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.

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.

Guidelines for the management of a brain death donor in the rhesus macaque: A translational transplant model

Introduction

The development of a translatable brain death animal model has significant potential to advance not only transplant research, but also the understanding of the pathophysiologic changes that occur in brain death and severe traumatic brain injury. The aim of this paper is to describe a rhesus macaque model of brain death designed to simulate the average time and medical management described in the human literature.

Methods

Following approval by the Institutional Animal Care and Use Committee, a brain death model was developed. Non-human primates were monitored and maintained for 20 hours after brain death induction. Vasoactive agents and fluid boluses were administered to maintain hemodynamic stability. Endocrine derangements, particularly diabetes insipidus, were aggressively managed.

Results

A total of 9 rhesus macaque animals were included in the study. The expected hemodynamic instability of brain death in a rostral to caudal fashion was documented in terms of blood pressure and heart rate changes. During the maintenance phase of brain death, the animal’s temperature and hemodynamics were maintained with goals of mean arterial pressure greater than 60mmHg and heart rate within 20 beats per minute of baseline. Resuscitation protocols are described so that future investigators may reproduce this model.

Conclusion

We have developed a reproducible large animal primate model of brain death which simulates clinical scenarios and treatment. Our model offers the opportunity for researchers to have translational model to test the efficacy of therapeutic strategies prior to human clinical trials.

ICU Management of the Potential Organ Donor: State of the Art

End-organ failure is associated with high mortality and morbidity, in addition to increased health care costs. Organ transplantation is the only definitive treatment that can improve survival and quality of life in such patients; however, due to the persistent mismatch between organ supply and demand, waiting lists continue to grow across the world. Careful intensive care management of the potential organ donor with goal-directed therapy has the potential to optimize organ function and improve donation yield.

Organ donation protocols

Organ transplantation improves survival and quality of life in patients with end-organ failure. Waiting lists continue to grow across the world despite remarkable advances in the transplantation process, from the creation of public engagement campaigns to the development of critical pathways for the timely identification, referral, approach, and treatment of the potential organ donor. The pathophysiology of dying triggers systemic changes that are intimately related to organ viability. The intensive care management of the potential organ donor optimizes organ function and improves the donation yield, representing a significant step in reducing the mismatch between organ supply and demand. Different beliefs and cultures reflect diverse legislations and donation practices amongst different countries, creating a challenge to standardized practices. Maintaining public trust is necessary for continued progress in organ donation and transplantation, hence the urge for a joint effort in creating uniform protocols that ensure transparent practices within the medical community.

Influence of specific thoracic donor therapy on kidney donation and long-term kidney graft survival

OBJECTIVE

To analyze the impact of a specific thoracic donor-treatment protocol (including restrictive fluid balance) on kidney donation and on kidney graft survival.

METHODS

A cohort study. Lung Donors and kidney recipients from 2003 to 2008 were the pre-protocol cohort, and those from 2009 to 2013 were the protocol cohort. The main outcome variables were graft survival and rate of kidney donation.

RESULTS

Kidney donation rates were similar in both periods (86.2 vs. 86.2 %; p > 0.05). Both donors and kidney recipients were older and with more comorbidities in the protocol group and this is the reason there were more cases of delayed graft function (differences not statistically significant) and with higher sequential creatinine levels of kidney recipients during the protocol period. However, graft survival was similar in both groups. The probability of graft survival 5 years after transplantation was 0.75 (95 % confidence interval 0.65-0.85) in the pre-protocol cohort and 0.81 (0.70-0.92) in the protocol cohort.

CONCLUSIONS

Specific treatment for multi-organ donors including restrictive fluid balance does not affect kidney donation or kidney graft loss, and has no impact on long-term viability. Hemodynamics must be closely monitored by medical personnel with specific training.

Brain death and care of the organ donor

Brain death has specific implications for organ donation with the potential for saving several lives. Awareness on maintenance of the brain dead has increased over the last decade with the progress in the field of transplant. The diagnosis of brain death is clinical and can be confirmed by apnea testing. Ancillary tests can be considered when the apnea test cannot be completed or is inconclusive. Reflexes of spinal origin may be present and should not be confused against the diagnosis of brain death. Adequate care for the donor targeting hemodynamic indices and lung protective ventilator strategies can improve graft quality for donation. Hormone supplementation using thyroxine, antidiuretic hormone, corticosteroid and insulin has shown to improve outcomes following transplant. India still ranks low compared to the rest of the world in deceased donation. The formation of organ sharing networks supported by state governments has shown a substantial increase in the numbers of deceased donors primarily by creating awareness and ensuring protocols in caring for the donor. This review describes the steps in the establishment of brain death and the management of the organ donor. Material for the review was collected through a Medline search, and the search terms included were brain death and organ donation.

Management of the Potential Organ Donor in the ICU: Society of Critical Care Medicine/American College of Chest Physicians/Association of Organ Procurement Organizations Consensus Statement

This document was developed through the collaborative efforts of the Society of Critical Care Medicine, the American College of Chest Physicians, and the Association of Organ Procurement Organizations. Under the auspices of these societies, a multidisciplinary, multi-institutional task force was convened, incorporating expertise in critical care medicine, organ donor management, and transplantation. Members of the task force were divided into 13 subcommittees, each focused on one of the following general or organ-specific areas: death determination using neurologic criteria, donation after circulatory death determination, authorization process, general contraindications to donation, hemodynamic management, endocrine dysfunction and hormone replacement therapy, pediatric donor management, cardiac donation, lung donation, liver donation, kidney donation, small bowel donation, and pancreas donation. Subcommittees were charged with generating a series of management-related questions related to their topic. For each question, subcommittees provided a summary of relevant literature and specific recommendations. The specific recommendations were approved by all members of the task force and then assembled into a complete document. Because the available literature was overwhelmingly comprised of observational studies and case series, representing low-quality evidence, a decision was made that the document would assume the form of a consensus statement rather than a formally graded guideline. The goal of this document is to provide critical care practitioners with essential information and practical recommendations related to management of the potential organ donor, based on the available literature and expert consensus.

Current research on organ donor management

A shortage of organs is available for transplantation, with 116,000 patients on the Organ Procurement and Transplantation Network/United Network for Organ Sharing wait list. Because the demand for organs outweighs the supply, considerable care must be taken to maximize the number of organs transplanted per donor and optimize the quality of recovered organs. Studies designed to determine optimal donor management therapies are limited, and this research has many challenges. Although evidenced-based guidelines for managing potential organ donors do not exist, research in this area is increasing. This article reviews the existing literature and highlights recent trials that can guide management.

Donor management and lung preservation for lung transplantation

Although lung transplantation has become a life-saving option for patients with end-stage lung disease, this intervention is hampered by a shortage of lungs in view of the growing number of people on the waiting list. Lungs are retrieved from only a small percentage of multiorgan donors, and the transplantation and intensive-care communities have recognised the need to develop innovative methods to expand the donor pool. Advancements in lung-preservation techniques in the preretrieval and postretrieval periods have increased the pool of available donors, and novel research and discoveries in this area have steadily improved post-transplantation adverse events. This Review summarises current best practice and the latest research on intensive-care management of a potential lung donor. We also discuss lung-preservation techniques, including advancements in normothermic ex-vivo lung perfusion, and the potential for a personalised medicine approach to the organ.

Management of the heartbeating brain-dead organ donor

The main factor limiting organ donation is the availability of suitable donors and organs. Currently, most transplants follow multiple organ retrieval from heartbeating brain-dead organ donors. However, brain death is often associated with marked physiological instability, which, if not managed, can lead to deterioration in organ function before retrieval. In some cases, this prevents successful donation. There is increasing evidence that moderation of these pathophysiological changes by active management in Intensive Care maintains organ function, thereby increasing the number and functional quality of organs available for transplantation. This strategy of active donor management requires an alteration of philosophy and therapy on the part of the intensive care unit clinicians and has significant resource implications if it is to be delivered reliably and safely. Despite increasing consensus over donor management protocols, many of their components have not yet been subjected to controlled evaluation. Hence the optimal combinations of treatment goals, monitoring, and specific therapies have not yet been fully defined. More research into the component techniques is needed.