163 20 Organ Donation Process and Management of the Organ Donor THOMAS A NAKAGAWA, MUDIT MATHUR, AND ANTHONY A SOCHET • Successful organ recovery for transplantation requires perioper ative donor mana[.]
20 Organ Donation Process and Management of the Organ Donor TH OMAS A NAKAGAWA, MUDIT MATHUR, AND ANTHONY A SOCHET • A significant gap continues to exist between the numbers of organ transplants and transplant recipients on the national waiting list in the United States.1 Children less than 18 years of age account for approximately 1.5% of all patients waiting for a transplant.1 The majority of children and adults have end-stage renal failure and are waiting for a renal transplant, followed by those with hepatic disease waiting for a liver.1 Despite fewer pediatric donors following neurologic death, the total number of pediatric transplants is increasing.1 There is also a continued increase in children receiving organ transplants from pediatric donors.1–3 Unfortunately, children still die waiting for a life-saving transplant The highest death rate observed occurs in those less than year of age.1–3 At the same time, the proportion of children removed as a transplant candidate from the waitlist and die because their underlying illness progresses continues to increase.1 Taken in sum, there is a growing need for donated organs and improved therapies to preserve existing organ function for those awaiting transplantation The global importance of organ donation is recognized and supported by the American Academy of Pediatrics (AAP) and other organizations.3,4 The AAP emphasizes education, the need to shape public policy, and a system in which organ procurement, distribution, and costs are fair and equitable to children and adults.4 Each state has laws and regulations for the determination of death that have been modeled after the Uniform Determination of Death Act (UDDA) in most cases.5 The UDDA provides a definition of death, stating that an individual who has sustained • • • • • Successful organ recovery for transplantation requires perioperative donor management expertise to correct physiologic derangements associated with neurologic death A collaborative, multidisciplinary approach to end-of-life care and donation requires early referral to the organ procurement organization, allowing medical professionals to dialogue and improve authorization rates while supporting families with end-of-life care decisions Determination of neurologic death in children is based on clinical criteria that are consistent across the age spectrum • PEARLS Donation after circulatory death (DCD) permits donation from patients who have suffered a catastrophic brain injury but not progress to neurologic death The sustained practice of pediatric DCD donation accounts for roughly 10% of all DCD donors nationally Patient and graft survival for organs, especially kidneys, transplanted from DCD donors is comparable to organ transplants from donation after neurologic death Neonatal donation provides another valuable opportunity to recover organs for transplantation either (1) irreversible cessation of circulatory and respiratory functions or (2) irreversible cessation of all functions of the entire brain (including the brainstem) is dead A determination of death must be made in accordance with accepted medical standards Criteria for the determination of death have been established in national guidelines for adults and children.6–8 In accordance with the dead donor rule, donation can only occur after death has been declared Donation cannot result in the death of the patient.9 An ethical discussion about defining and determining death and the dead donor rule are beyond the scope of this chapter (see Chapter 18) Organ donation can occur following neurologic death (donation after brain death [DBD]), following circulatory death (donation after circulatory death [DCD]), or through living donation The vast majority of organs are recovered following death established by neurologic criteria Donor organs potentially recovered for transplantation are dependent on the type of donation Organs recovered from DBD include the heart, lungs, liver, kidneys, pancreas, and intestines Organs recovered following DCD include lung, liver, kidneys, and pancreas Additionally, hearts have been recovered from DCD donors.10,11 Tissues including skin, bone, cartilage, heart valves, and corneas can be recovered from both DBD and DCD donors Most pediatric deaths occur in intensive care units (ICUs) following the unplanned withdrawal of life-sustaining medical therapies,12 making opportunities for pediatric donation a rare event Missed opportunities for organ donation occur for many 163 164 S E C T I O N I I I Pediatric Critical Care: Psychosocial and Societal reasons, but the majority can be accounted for when a family declines the option of donation Families may not have been provided the opportunity for donation because the medical team did not recognize donor eligibility Approaching families about donation at an inappropriate time, failing to develop a shared cognitive model for the concept of brain or circulatory death, unreliable or misleading educational resources, and racial barriers may also contribute to declined authorization rates.3,13–16 Even after authorization, potential organs for transplantation may become unsuitable because of caregivers’ lack of familiarity with appropriate donor management, damage during recovery prior to transplantation, and medical examiner or coroner denials.13 Families who authorize donation are more likely to comprehend neurologic death and report a positive hospital experience compared with families that choose not to authorize donation.17 Unique aspects related to pediatric organ donation and transplantation are listed in eBox 20.1 Process of Organ Donation Organ donation should be viewed as a process Like many other aspects in medicine, this process evolves over time and includes (1) identification of a potential donor, (2) determination of neurologic death in a timely manner, (3) authorization for organ donation, (4) perioperative management of the donor, and (5) recovery of organs for transplantation The donation process begins when a critically ill or injured child is identified as a potential donor, with an early or timely referral to the organ procurement organization (OPO) A federal mandate requires notification of the designated OPO for any impending death Early involvement and timely notification prior to the determination of death generates a greater amount of time for collaboration with the OPO.18 This best practice permits coordination of the donation process with the medical team.3,4,14,18–20 Ensuring OPO engagement and the intensive care team’s understanding of the entire donation process is essential to eliminate confusion that may disrupt the donation process Ensuring this best practice not only improves authorization rates but also assists families with understanding and coping with end-of-life care issues A protective stance with parents or guardians of children because of preconceptions about donor eligibility may have the unintended consequence of denying families the opportunity to help or save the life of another person.21 Prior to approaching the family, the medical team and OPO should discuss potential donor suitability and coordinate the best way to approach a family about organ donation.3,4,14,18,19 Many national and international organizations have emphasized donation as a routine part of end-of-life care and have adopted this collaborative best practice to increase authorization and recovery of organs for transplantation.3,4,18,20,22,23 Discussions about donation with parents or guardians may differ from spouse or relatives of adult donors Contrary to the traditional approach of the OPO coordinator requesting donation and decoupling the death and authorization process, one study found that the timing of organ donation discussions did not appear to influence donation decisions.24 Parents want sufficient time to discuss end-of-life care issues, including donation, and may prefer discussions regarding donation with the pediatric intensivist or a member of the healthcare team they have come to trust.3,24 Few families of either adults or children appear to suffer psychological harm by having the option of donation presented to them.21 In addition to collaboration with the OPO, successful authorization for pediatric donation may include the engagement of palliative care specialists Palliative providers may act as an additional resource to assist the ICU team and provide family support during end-of-life care discussions and organ donation.25,26 The benefits of organ donation extend beyond the transplant recipient There are psychological and social benefits for the potential donor’s family Organ donation may assist families in finding solace in the belief that their child’s death was not without meaning and helped or saved the life of other people.3,27 Knowing that their child will be remembered after death is one important way that organ donation helps families heal Role of the Pediatric Intensivist and Critical Care Team in the Process of Organ Donation Management of critically ill children and pediatric organ donors is best accomplished at a tertiary or quaternary pediatric facility that provides specialized pediatric critical care expertise required to manage this select group of patients.14,18 Medical management of the potential pediatric organ donor requires knowledge of the physiologic derangements associated with this patient population Hemodynamic instability, alterations in oxygenation and ventilation, metabolic and endocrine abnormalities, and coagulation disturbances are common Support and care of the family provided by a team of physicians, nurses, social workers, chaplains, family service providers, organ donation specialists, and other support staff trained in the unique aspects of pediatric medicine are integral to the care of these children and their families.3,14,18 The pediatric intensivist is central in coordinating care to ensure the successful recovery of organs from pediatric donors The integral involvement of the pediatric intensivist and critical care team in the management of critically ill and injured children has been a foundation of clinical practice in many successful pediatric centers Involvement of critical care specialists— especially in pediatric donation, in which there is a limited and decreasing number of donors—improves the quality and number of organs recovered.14,18 Caring for the critically ill child and the child’s family through all phases of illness, including end-of-life issues, should be a seamless transition The continuum of care for the dying patient who progresses to death and becomes a donor requires the expertise of the pediatric intensivist and critical care team to preserve the option of donation.8 Patient management to prevent deterioration of organ systems and subsequent loss of transplantable organs while helping family members deal with the death of their child is fundamental to facilitating the donation process and successful recovery of organs for transplantation National and international best practices for deceased organ donation emphasize that patient management should preserve the option of donation for potential donors prior to and after declaration of death.3,4,14,17–20,22,23 Preconceptions about eligibility for donation by the critical care team may not be current or accurate Suitability of donor organs for transplantation is best assessed by the OPO.18 Thresholds for acceptable organ dysfunction can vary according to time of evaluation, transplant program comfort levels, and recipient urgency For example, serial echocardiograms may demonstrate donor response to effective medical therapy, enabling cardiac recovery for transplantation: a positive blood culture or bacterial meningitis may not preclude organ donation if antibiotic therapy has been administered.18 In the United States health policy changes have impacted donor eligibility The HIV Organ Policy Equity Act enacted in 2013 allows HIV-positive donors to donate organs for transplantation into HIV-positive recipients Additionally, organs 164.e1 • eBOX 20.1 Unique Issues With Pediatric Organ Donation and Transplantation • Parents and guardians must act as surrogate decision makers without benefit of being guided by the donor’s wishes, as is often possible with adults • There is age-related variation in the timing associated with determination of brain death • There are technical challenges related to surgical procedures in smaller children and infants • Acquisition and use of organs recovered from children may be limited by size and weight constraints • Specialized care required for the management of critically ill children and pediatric organ donors may be lacking at institutions without pediatric expertise CHAPTER 20 Organ Donation Process and Management of the Organ Donor from hepatitis-positive donors are now being transplanted Although these situations may be uncommon for pediatric patients, it emphasizes the need to be aware of the latest developments in public policy and use the expertise of the OPO as part of highquality end-of-life care.18 Collaboration with investigative teams, medical examiners, and coroners in cases of accidental or nonaccidental death is imperative to determine cause of death and allow the donation process to proceed.13,18 Preservation of evidence and early consultation and discussions with the coroner, medical examiner, or forensic team may result in requests for additional noninvasive imaging needed to supplement the death investigation without precluding donation Determination of Neurologic Death Most organ donations occur following neurologic death; therefore, the determination of neurologic death must precede any efforts to recover organs Timely and efficient determination of neurologic death is important for several reasons: it allows the family to begin the grieving process as they prepare for the loss of a loved one; if donation is planned, organ preservation and preparation for recovery can begin; and if donation is not planned, medical therapies can be stopped, permitting redistribution of scarce ICU resources to other critically ill and injured patients Determination of neurologic death must never be rushed or take priority over the needs of the patient or the family Appropriate emotional support for the family should be provided, including adequate time to grieve with their child after death has occurred Determination of neurologic death in children is a clinical process based on specific criteria consistent across the age spectrum Criteria for the determination of neurologic death in infants and children in the United States were revised in 2011.6,7 These guidelines outline the minimum criteria to determine neurologic death for infants greater than 37 weeks estimated gestational age to 18 years of age The guidelines not challenge the definition but rather provide criteria for the determination of death Although examination criteria for infants, children, and adults are similar, determination of irreversible injury and neurologic death can be more challenging in younger patients because of physiologic and anatomic differences, along with differences in the mechanism of injury in infants and children.6–8 Hypoxic-ischemic or traumatic brain injuries are the most common causes of neurologic death for infants and children.28 Two chronologically distinct, unbiased, independent neurologic examinations and age-based recommendations are a primary difference between adult and pediatric guidelines to determine neurologic death.6–8 eBox 20.2 lists the recommended observation periods based on the current pediatric guidelines for the determination of neurologic death A clinical history, known cause of coma, and neurologic injury consistent with the clinical presentation are prerequisites to establish that an irreversible condition has occurred Neurologic criteria to determine death in infants and children are listed in eBox 20.3 Normal physiologic parameters must be established and maintained before a determination of neurologic death or neurodiagnostic testing can be meaningful Coma and apnea must coexist In addition, confounding variables must be corrected before an evaluation of neurologic death Conditions that may interfere with the neurologic examination or factors capable of causing a comatose state imitating brain death should be considered, corrected, and ruled out 165 These include hypothermia, hypotension, severe hepatic or renal dysfunction, inborn errors of metabolism, metabolic disturbances including hypoglycemia, and toxic or iatrogenic ingestions Toxins can interfere with the neurologic examination and should be considered in cases in which a definitive etiology of coma cannot be established Longer-acting or continuous infusion of sedative agents and recent administration of neuromuscular blocking agents can interfere with the neurologic examination When determining the appropriate timing of the clinical examination, the half-life of previously administered agents must be considered End-organ dysfunction and the use of therapeutic hypothermia can delay pharmacologic clearance Adequate time for clearance of sedatives and neuromuscular blocking agents must be provided Testing for drug intoxication—including barbiturates, opiates, and alcohol—should be performed as indicated Clearance of neuromuscular blocking agents can be confirmed by use of a nerve stimulator There may be situations in which these conditions cannot be corrected and an ancillary study may be required to assist with the determination of neurologic death For instance, the use of barbiturate coma in traumatic brain injury may require a prolonged observation period to ensure that measured levels are in the lowto mid-therapeutic range before a clinical determination of neurologic death can occur Barbiturates reduce cerebral blood flow (CBF); however, there is no evidence that high-dose barbiturate therapy completely arrests CBF Radionuclide CBF study or cerebral arteriography can be used in patients receiving high-dose barbiturate therapy to demonstrate the absence of CBF.6,7 Patients receiving targeted temperature management and hypothermia protocols require adequate time for drug clearance following rewarming prior to initiating testing for neurologic death Current adult and pediatric guidelines in the United States and Canada recommend a minimum core body temperature of 35°C (95°F).6–9,29 The United States pediatric guidelines suggest waiting at least 24 hours following rewarming before instituting testing for neurologic death.6,7 A period greater than 24 hours following targeted temperature management may be required to determine neurologic prognostication and ensure that diagnostic error does not occur when determining neurologic death.30–33 Testing for Apnea Apnea testing is a critical and essential component of the clinical examination to determine neurologic death Testing for apnea will result in respiratory acidosis and potential hypoxemia Therefore testing must be performed safely with special attention to maintaining ideal oxygenation and hemodynamics Apnea testing should be performed only after the patient has met the clinical criteria for neurologic death.6,7 Apnea testing must allow adequate time for the partial pressure of carbon dioxide (Paco2) to increase to levels that would normally stimulate respiration Baseline Paco2 should be measured and allowed to rise to 60 mm Hg or greater and 20 mm Hg above the baseline to account for infants and children with chronic respiratory disease or insufficiency who may breathe only in response to supranormal Paco2 levels.6,7 The patient should be continually observed for any spontaneous respiratory movements over a 5- to 10-minute period or longer, with documentation of arterial blood gas(es) reaching the targeted threshold During apnea, the Paco2 rises approximately to mm Hg/min.6,7 Venous blood gas measurements have not been sufficiently studied to document elevated CO2 during apnea testing 165.e1 • eBOX 20.2 Recommended Observation Periods to Determine Brain Death in Infants and Children • Term infants (37 weeks’ estimated gestational age) to 30 days of age: Two examinations and apnea tests separated by at least 24 hoursa • More than 30 days to 18 years of age: Two examinations and apnea tests separated by at least 12 hoursb a The observation period may be decreased if an approved ancillary study is used A second clinical examination and apnea test must be performed following the ancillary study to declare death Data from Nakagawa TA, Ashwal S, Mathur M, et al Guidelines for the determination of brain death in infants and children: an update of the 1987 Task Force recommendations Crit Care Med 2011;39(9):2139–2155; and Nakagawa TA, Ashwal S, Mathur M, et al Clinical report—Guidelines for the determination of brain death in infants and children: an update of the 1987 task force recommendations Pediatrics 2011;128(3):e720–740 • eBOX 20.3 Neurologic Examination Criteria for Brain Death Determination in Infants and Children Coma Patient must lack all evidence of responsiveness Noxious stimuli should not produce a motor response other than spinally mediated reflexes Apnea The patient must have the complete absence of documented respiratory effort (if feasible) by formal apnea testing demonstrating a Paco2 60 mm Hg and 20 mm Hg increase above baseline Paco2 Loss of all brainstem reflexes, including: • Midposition or fully dilated pupils that not respond to light • Absence of movement of bulbar musculature, including facial and oropharyngeal muscles • Absent gag, cough, sucking, and rooting reflexes • Absent corneal reflexes • Absent oculovestibular reflexes Flaccid tone and absence of spontaneous or induced movements, excluding spinal cord events such as reflex withdrawal or spinal myoclonus Reversible conditions or conditions that can interfere with the neurologic examination must be excluded prior to brain death testing Data from Nakagawa TA, Ashwal S, Mathur M, et al Guidelines for the determination of brain death in infants and children: an update of the 1987 Task Force recommendations Crit Care Med 2011;39(9):2139–2155; and Nakagawa TA, Ashwal S, Mathur M, et al Clinical report—Guidelines for the determination of brain death in infants and children: an update of the 1987 task force recommendations Pediatrics 2011;128(3):e720–740 ... required to manage this select group of patients.14,18 Medical management of the potential pediatric organ donor requires knowledge of the physiologic derangements associated with this patient population... the determination of death generates a greater amount of time for collaboration with the OPO.18 This best practice permits coordination of the donation process with the medical team.3,4,14,18–20... donation process is essential to eliminate confusion that may disrupt the donation process Ensuring this best practice not only improves authorization rates but also assists families with understanding