The effect of arginine vasopressin on organ donor procurement and lung function

Patient management for thoracic organ donor candidates: the lung transplantation team's view

Despite the increasing demand for lung transplants, donor lungs remain in short supply. Although organ donations have been steadily increasing in Korea, with the utilization rate for donor lungs increasing to 40% in recent years, many potential donor organs remain unused. To match the increasing number of patients on the lung transplant waitlist, it is essential to increase the donor procurement rate through optimal management. Improvements in donor lung management programs can lead to expansion of the donor pool and optimal posttransplant outcomes. This review focuses on basic protocols for the optimal management of donor lungs and summarizes coronavirus disease 2019-related considerations for donor lung evaluation.

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.

Donor lung management: Changing perspectives

Worldwide, lung transplantation has been a therapeutic option for select end-stage lung disease patients who are on optimized medical regimens, but the underlying clinical condition continues to progress. For any successful lung transplantation program, it is important to have a robust donor lung management program. Lungs are commonly affected by the various factors related to trauma or neurogenic in brain stem death donors. This article would focus on the basic protocols to optimize donor lungs which would help in increasing donor pool. It would also elaborate COVID-specific points for donor lung evaluation. This article would also describe the criteria for ideal as well as marginal donor lungs. A comprehensive literature search was performed using PubMed to review various articles related to donor lung management.

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.

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.

Hormone replacement therapy in brain-dead organ donors: a comprehensive review with an emphasis on traumatic brain injury

BACKGROUND

Organ shortage is an ongoing problem in the United States. Most donor organs are procured following brain death and a significant portion of brain-dead donors result from devastating brain injury. Without a standard practice for hormone replacement therapy (HRT) in the setting of brain death, a comprehensive review of the literature was deemed necessary.

METHODS

A search of published literature was conducted with terms "TBI" or "brain injury" or "head injury" AND "hormone" or "management" AND "organ" AND "donor" or "donation." Abstracts and full texts were screened for relevance and inclusion of information on HRT. Additional studies were selected from references cited within these. Excluded studies were non-English, nonhuman based, or had small sample size, (i.e., case reports or series with fewer than five subjects).

RESULTS

Fifteen studies were selected for inclusion and contained Level III or Level IV evidence. Combinations of thyroid hormone, insulin, and corticosteroids were the most commonly cited HRT. Ninety-three percent of studies found a significant increase in organ procurement rate among donors who received HRT. Hormone replacement therapy was administered after brain death declaration in eight studies. Only two studies specifically explored the effects of starting HRT earlier and identified even greater procurement rates. Four studies were specific to traumatic brain injury (TBI); the remaining 11 studies involved TBI in 22% to 89% of the sample.

CONCLUSION

Organ shortage remains a growing problem in the United States. Donor management including HRT has been proposed to combat the endocrine derangement associated with brain death and, in particular, TBI. While the existing literature reported compelling outcomes using HRT, there remains a need for further Level I and Level II evidence studies to define optimal practice.

LEVEL OF EVIDENCE

Review article, level IV.

[Critical care management of the potential organ donor : Current recommendation for adults]

The shortage of donor organs has not improved in recent years. To increase the number and success of transplantation it is crucial to optimize the processes of early identification of potential organ donors and structured critical care management. The therapy starts long before brain death is diagnosed. Structured in-house organ donor management protocols ensure a highly qualified critical care that has a direct impact on the transplantation outcome. The therapy is based on the established standards. The main focus is on differentiated catecholamine and volume therapy. Vasopressin, in combination with norepinephrine, is effective for both treating vasoplegia and electrolyte disturbances. Despite poor evidence, steroids are useful for stabilizing hemodynamics and treating the consequences of neuroendocrine dysfunction. Overall, prospective studies are required to give general recommendations for critical care.

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.

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.

Pharmacists' guide to the management of organ donors after brain death

PURPOSE

This article reviews organ donor pathophysiology as it relates to medication use with the goal of maximizing the successful procurement and transplantation of donor organs.

SUMMARY

The number of patients requiring organ transplantation continues to grow, yet organ donation rates remain flat, making it critical to appropriately manage each organ donor in order to ensure viability of all transplantable organs. The care given to one organ donor is tantamount to the care of several transplant recipients. Aggressive donor management ensures that the largest number of organs can be successfully procured and improves the organs' overall quality. Hospital pharmacists are responsible for processing orders and preparing the medications outlined in donor management algorithms developed by their respective medical systems. It is important that pharmacists understand the details of the medications used in these protocols in order to critically evaluate each medication order and appropriately manage the donor. Typical medications used in organ donors after brain death include medications for blood pressure management and fluid resuscitation, medications necessary for electrolyte management, blood products, vasopressors, hormone replacement therapy, antiinfectives, anticoagulants, paralytics, and organ preservation solutions.

CONCLUSION

It is essential to provide optimal pharmacotherapy for each organ donor to ensure organ recovery and donation. Typical medications used in organ donors include agents for blood pressure management and fluid resuscitation, medications necessary for electrolyte management, blood products, vasopressors, hormone replacement therapy, antiinfectives, anticoagulants, paralytics, and organ preservation solutions.

Endocrine Considerations of the Pediatric Organ Donor

Patients determined to be neurologically deceased exhibit potentially harmful changes in various endocrine pathways due to disruptions of the body's neurohormonal control mechanisms. These deviations from endocrine homeostasis lead to hemodynamic, metabolic, and immunologic aberrations that are associated with reduced graft procurement and function for the purposes of organ donation. Existing literature has attempted to describe the pathophysiology that associates disruptions in endocrine pathways with organ dysfunction, both to increase understanding and to identify strategies to support the donor. For example, diabetes insipidus due to arginine vasopressin deficiency is commonly encountered, and should be anticipated. The significance of abnormalities in other pathways such as those involving cortisol and thyroid hormone is less established; however, there is increasing support for treating potential organ donors with combined hormonal therapies. While there are published documents aimed at guiding management of organ donors in general, many controversies exist and pediatric-specific literature is scarce. This article aims to review several of the important endocrine-specific aspects of managing the neurologically deceased organ donor, with an emphasis on pediatrics where information is available.

Trends in organ donor management: 2002 to 2012

BACKGROUND

Refinements in donor management have resulted in increased numbers and quality of grafts after neurologic death. We hypothesize that the increased use of hormone replacement therapy (HRT) has been accompanied by improved outcomes over time.

STUDY DESIGN

Using the Organ Procurement and Transplant Network donor database, all brain-dead donors procured from July 1, 2001 to June 30, 2012 were studied. Hormone replacement therapy was identified by an infusion of thyroid hormone. An expanded criteria donor was defined as age 60 years or older. Incidence of HRT administration and number of donors and organs recovered were calculated. Using the Organ Procurement and Transplant Network thoracic recipient database transplant list, wait times were examined.

RESULTS

There were 74,180 brain-dead donors studied. Hormone replacement therapy use increased substantially from 25.6% to 72.3% of donors. However, mean number of organs procured per donor remained static (3.51 to 3.50; p = 0.083), and the rate of high-yield donors decreased (46.4% to 43.1%; p < 0.001). Incidence of traumatic brain injury donors decreased (42.1% to 33.9%; p < 0.001) relative to an increased number of expanded criteria donors (22.1% to 26%). Despite this, there has been an increase in the raw number of donors (20,558 to 24,308; p < 0.001) and organs (5,857 to 6,945; p < 0.001). There has been an increase in organs per traumatic brain injury donor (4.02 to 4.12; p = 0.002) and a decrease in days on the waiting list (462.2 to 170.4 days; p < 0.001) for a thoracic transplant recipient.

CONCLUSIONS

The marked increase in the use of HRT in the management of brain-dead donors has been accompanied by increased organ availability overall. Potential mechanisms might include successful conversion of previously unacceptable donors and improved recovery in certain subsets of donors.

Treating the donor

PURPOSE OF REVIEW

Current pressures of organ supply and demand require maximization of potential for organ donation. The donor population is older and has more significant comorbidity than in the past.Optimal management of the donor after brain death (DBD) is essential to ensure that the greatest number of organs can be transplanted per donor. Defining evidence-based drugs and techniques to assist this has never been more important.

RECENT FINDINGS

Care of patients with catastrophic brain injury incorporating supportive therapy targeted at specific goals and delivered by experienced specialists provides the best donation outcomes. Such pathways represent best practice critical care applied to this population. In this context, the value of some previously recommended therapies appears questionable and warrants reassessment. Prolonged (>24 h) incorporeal organ conditioning may have significant benefits.Extracorporeal support in the resuscitation arena is emerging and, in patients who fail to respond, may yield a new source of donors.

SUMMARY

Early identification of potential DBD, best practice critical care, and achieving defined treatment goals are associated with more transplantable organs. Study of a complex intervention like donor management presents significant problems of organization, ethics and consent. This situation is recognized internationally and progress is being made.