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Brain Death and Organ Donation
L5885/00 $15.00 +-~ Neurotrauma
Brain Death and Organ Donation Darlene Lovasik, MN, RN, CCRN, CNRN
Critical care nurses and physicians work to delay death every day; however, when one asks these health care providers for the definition of death, the diverse answers include physiologic, legal, religious, and moral descriptions. Defining death is not as clear as it was in the past, and changes in the definition of death have been driven by advances in organ transplantation. One of the primary reasons for determining brain death is to ascertain if the patient is a potential organ donor. By recognizing the process of death, surgeons are able to recover transplantable organs. Other improvements in organ transplant surgery, immunology, and pharmacology, particularly the use of cyclosporin and other antirejection drugs, have saved and prolonged the lives of the organ recipients. Because of the biomedical advances of the past 40 years, patients surviving catastrophic events are connected to mechanical devices that sustain their lives, even without evidence of cerebral activity. Hospitals use established guidelines for the clinical diagnosis of brain death, then follow procedures for brain death certification. The primary causes of brain death are head trauma, particularly motor vehicle crashes and gunshot wounds, and cerebral hemorrhage.
From the University of Pittsburgh Hccalth System, Pittsburgh. Pennsylvania
Most people would describe death as the cessation of cardiac and pulmonary activity or heart-lung death. One funeral custom that continues today began as a process to determine death. After preparing a deceased person for burial, family and friends gathered together to eat and wait to see if the departed would wake up. "Wakes" continue to be observed today. The fear of being buried alive continued in England during the Middle Ages. The departed had a string tied to his or her wrist that went through the coffin, up through the ground, and tied to a bell. Someone would sit in the graveyard at night to listen to the bell, so on the graveyard shift, they would know that someone was "saved by the bell" or was a "dead ringer." Coffins with breathing tubes could be purchased in Germany in the late 19th century. 19 Other means of determining death included checking for respiration by using a candle or mirror, testing the nervous system through the use of smelling salts or a trumpet, and evaluating the circulation via bleeding. 15 20 With the introduction of mechanical ventilation, a new clinical condition was noted. Coma depasse or state beyond coma was first described in 1959 in France. 10 In 1967, Dr. Christian Bernard in South Africa performed the first human-to-human heart transplant. Although the donor may have met the criteria
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now used for brain death, she was removed from life support and became asystolic, and retrieval of the heart did not begin until 12 minutes after she had been declared dead. This controversial situation ignited medical, legal, moral, and ethical debate that continues today.
Criteria for Brain Death Anticipating further experimentation using cadaver organs, the Harvard Ad Hoc Committee on Irreversible Coma met in 1968 and published the first guidelines for establishing brain death in the Journal of the American Medical Association in August 1968. 1This was followed in 1970 by the Determination of Death Act in Kansas. In 1981, the President's Commission for the Study of Ethical Problems in Medicine and Biomedical and Behavior Research stated that criteria for brain death should include the following documentation: 1. The condition of the patient is irreversible and must have a known cause. 2. Cerebral and brain stem functions are absent. 3. Cessation of all brain functions has persisted through a period of observation.17, 21, 21 The President's Commission defined death as either the irreversible cessation of function of the heart and lungs or irreversible loss of all functions of the entire brain. This is significant because it states that brain death is not a different type of death but is equivalent to heartlung death. Since 1981, all 50 states have recognized the Uniform Determination of Death Act: 1. An individual who has sustained either: (1) irreversible cessation of circulatory and respiratory functions or (2) irreversible cessation of all functions of the entire brain, including the brain stem, is dead. A determination of death shall be made in accordance with accepted medical standards. 2. The irreversible loss of all brain function: (1) the cerebral hemispheres with loss of cognitive function and (2) the brain stem with loss of respiratory and circulatory activities. 17 · 21 · 22 · 24
Clinical Criteria for Brain Death Before making a clinical diagnosis of brain death, the cause of the patient's coma must
be established. Clinical or neuroimaging evidence must explain the irreversible cessation of all brain function. Factors other than primary brain injury that may impair brain function must be absent. The following complicating medical conditions should be excluded: (1) shock, (2) hypothermia, (3) absence of central nervous system depressants, (4) metabolic abnormality, and (5) correctable abnormalities. One of the primary signs of shock is a decreased level of consciousness as a result of reduced cerebral perfusion. The patient's blood pressure should be at least 90 mm Hg systolic or no greater than 10 mm Hg below the patient's usual systolic pressure with evidence of adequate tissue perfusion to exclude shock as the cause of a decreased level of consciousness. Hypothermia also drastically diminishes both cerebral blood flow and oxygen requirements. Although is it unusual, victims who appear to be clinically dead because of marked depression of brain and cardiovascular function may be resuscitated. Therefore, the core body temperature must be at least 32°C before declaring death. "No one is dead until they are warm and dead." 25 A substantial dose of central nervous system (CNS) depressants can also mimic brain death. When drugs are implicated as a possible cause or contributory factor in the comatose patient, or in a patient with a coma of unknown cause, toxicologic screening and analysis are required. This includes sedatives and anesthetics such as barbiturates, benzodiazepines, meprobamate, and alcohol. If neuromuscular blocking agents such as succinylcholine or vecuronium have been used, normal neuromuscular transmission is determined by using a nerve stimulator to evaluate function. Patients who have received recent general anesthesia must be observed for a sufficient period to allow for the elimination of the anesthetic based on the pharmacology of the agent. If the blood levels of CNS depressants are in the therapeutic or toxic range or if the blood alcohol level is equal to or greater than 100 mg/ dL, the patient cannot be declared brain dead without a confirmatory test an absence of blood flow to the brain. Patients with alcohol levels less than 100 mg/ dL or CNS depressant levels in the subtherapeutic range may be declared brain dead only when the patient has suffered an
BR/l,!f\1 DEATH AND ORGAN DONATION
obvious lethal brain injury as indicated clinical examination and supported by CT scanning blunt head injury with massive brain swelling and herniation or bihemispheric gunshot wounds). Both alcohol and CNS depressants must be absent to declare brain death in the patient with an unknown cause of coma. Metabolic abnormalities should be absent including electrolyte abnormalities, acidbase disturbances, or endocrine disturbances that are known to impair brain function (e.g., hepatic encephalopathy, hyperosmolar coma, severe uremia, or hypothyroidism). Finally, the patient undergoes a period of observation after treatment for potentially correctable abnormalities such as hypoxemia, hypotension, hypovolemia, hypothermia, and severe electrolyte disturbances before beginning an evaluation of brain death. i. P. 20-n 24
Clinical Brain Death Examination The clinical examination for brain death establishes the absence of cerebral and brain stem functions. Evaluation of the cerebral cortex begins by confirming unresponsiveness, a lack of verbal response, lack of coordinated eye movements, and an absence of motor activity, including decorticate and decerebrate posturing. Spontaneous motor activity, shivering, seizures, or any response to painful stimuli must be absent. JS. 26 · 27 · 29 The remainder of this assessment determines brain stem function. The pupillary response demonstrates function of cranial nerves II and III. The pupils should be nonreactive to light stimulation. This reflex may be unreliable after the use of cocaine, opiates, scopolamine, atropine, dopamine, or mydriatic eye drops or in the patient with eye trauma or disease, including cataracts. 15 · 2<' 27 • 29 The two ocular movements evaluated are the oculocephalic (doll's eyes) and oculovestibular (ice-water calorics) responses. The oculocephalic reflex illustrates function of cranial nerves III, VI, and VIII and is tested by rapidly turning the head laterally from rniclposition to 90° on both sides. The normal response (with an intact brain stem) is for the eyes to move opposite to the head turning. If the reflex is absent, the eyes will remain fo1ward with rapid head turning. Testing the oculocephalic reflex is contraindicated in the patient with a known or suspected cervical spinal inju1y. Ji. 26 · 29
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The oculovestibular reflex is controlled cranial nerves III and VIII and is tested by the irrigation of at least 50 mL of ice-cold water or saline into each external auditory canal with the patient's head elevated to 30°. The patient must be observed for any movement of the eyes. With an intact brain stem, the eyes will slowly move toward the irrigated ear. If the cortex is still functioning, this may be followed by rapid nystagmus in the opposite direction. An absent response reveals that the brain stem is no longer functioning. 10 Wait 5 minutes before injecting into each ear. Blood and cerumen in the ears, sedatives, anticholinergics, and ototoxic antibiotics may abolish this reflex. The corneal reflex measures the function of cranial nerves V and VII. The patient should have no facial grimacing to painful stimuli and the corneal reflex, tested by using a cottontippecl swab, should be absent. JS. 26 · 27 · 29 The gag or cough reflex is controlled by cranial nerves IX and X. The gag reflex should be absent with pharyngeal stimulation, and the patient should not cough following deep tracheal suctioning. 1'· 26 · 27 · 29 Atropine is used to assess the status of vagus nerve, cranial nerve X. Following a dose of atropine, 2 mg IV bolus, the heart rate should increase. If the vagus nerve nuclei is not responsive, less than a 5 beat per minute (bpm) response follows the injection. Apnea testing is based on evidence that carbon dioxide is the strongest stimulus for spontaneous respiration. Because the brain stem is responsible for sensing and responding to changes in Paco 2 (partial pressure of dissolved carbon dioxide) and pH, apnea is the result of a nonfunctioning brain stern. Spontaneous breathing or any evidence of respiratory effort must be absent while the ventilator is discontinued. The patient is provided 100% oxygen (OJ through the ventilator in the continuous positive airway pressure (CPAP) mode or through an oxygen cannula placed down the enc.lotracheal tube to the level of the carina with oxygen delivered at a minimum of 6 L/min. If the arterial Pco 2 increases to 60 mm Hg or greater or with an increase in Pco 2 of at least 20 mm Hg above the patient's normal Pco 2 without a respiratory response, it is evidence that the brain stem has ceased to function. Arterial blood gases (ABGs) are measured to document both Pao 2 and Paco 2 levels. There may be complications
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associated with apnea testing, including hypotension and cardiac dysrhythmias. 15 • 27 · 29
Adjunctive Tests The following tests are recommended when severe metabolic abnormalities such as uremia, hepatic encephalopathy, or other metabolic encephalopathies are present; apnea testing cannot be performed; when the primary brain insult is infratentorial; or when the cause of brain death is uncertain or is due to global ischemia or anoxic injury. These adjunctive tests can be performed at the bedside. A single 16- or 18-channel electroencephalogram (EEG) should demonstrate electrocerebral silence for at least 30 minutes of recording. It is recommended that a neurologist using the guidelines developed by the American Electroencephalographic Society makes the interpretation of the EEG. Because an EEG evaluates the cerebral cortex only, and not the function of the brain stem, it is not mandatory for confirming brain death. 20 A transcranial doppler can be used over the intracranial arteries to determine absent diastolic or reverberating flow, small systolic peaks, or absent signals in an unresponsive patient. This is particularly useful with the patient who previously had transcranial doppler signals. is, 26 · 27 • 29 Somatosensory evoked potentials (SSEPs) are used to measure bilateral median nerve stimulation. SSEPs and Brain Stem Auditory Evoked Responses (BAERs) will be absent in the brain-dead patient. is, 26 · 27 · 29 Sustained increased intrancranial pressure (ICP) within 10 to 20 mm Hg of the mean arterial pressure (MAP) is also a poor prognostic sign.
Confirmatory Tests Confirmatory tests that demonstrate absent cerebral blood flow are performed to verify clinical brain death examination when the patient examination is confounded by drug or alcohol intoxication, neuromuscular blockade, or hypothermia. They generally require transporting the patient to the diagnostic procedure area. Four-vessel (carotid and vertebral contrast cerebral angiogram will reveal absent intracranial filling at the level of the carotid bifurcation or circle of Willis.
Xenon cerebral blood flow (CBF) studies using either radioactive or stable xenon should demonstrate mean cerebral blood flow of less than 5 mL/100 g/min (normal is 50 mL/100 g/min) to authenticate brain death. Cranial radionuclide angiography using technetium 99m should demonstrate absent supratentorial flow. 23 The PET scanner measures cerebral metabolism, but the cost and limited availability of this technology makes this prohibitive at this time. 15 • 26· 27
Special Concerns It is recognized that there are some situations
that may require further testing. Spinal reflexes may produce movement of some muscle groups, and the origin of this activity should be verified by cerebral blood flow studies. The patient should not exhibit an autonomic response to pain, such as a change in pulse or blood presure. Finally, an EEG with random electric activity cannot be used to determine brain death. A few cerebral functions such as temperature regulation and anterior and posterior pituitary function continue following the diagnosis of brain death. Questions may also arise in patients with minimal cerebral blood flow or some preserved brain stem function. 14• is, 29
Brain Death in Pediatrics Guidelines have been established for the determination of brain death in infants and young children. These guidelines differ from the guidelines established for adults. The immature brain may be viable despite the absence of EEG activity or other classic determinants of brain death; therefore, a longer period of observation is recommended. For neonates, life support is continued until at least 7 days of age. The observation period recommended for infants 7 to 60 days of age is 48 hours; for infants 61 days to 12 months old, 14 hours; and for children over 1 year of age, 12 hours. 15 • 29
Certification of Death After the clinical examination and recommended diagnostic tests have been completed and the results show no evidence of
BRAIN DEATH AND ORGAN DONATION
continuing brain the patient is certified dead. A few states specify which medical specialties are permitted to declare brain death. Many institutions require two separate clinical examinations with an interval of 2 to 6 hours or examination by two physicians demonstrating complete absence of all brain function for certification of brain death. It is recommended that members of the transplantation team not be involved in the death certification of a brain-dead organ donor.
hospitals use a form for brain death certification that is completed by the physicians (Fig. 1). Brain death certification is equivalent to the traditional pronouncement of death, and the time of death documented for this certification is the time of death to be used for all legal documents. Life support may be withdrawn following certification and pronouncement of brain death except when the deceased is an organ donor. Cardiopulmonary and other essential
Clinical Evaluations C:mse of Brain D e a t h - - - - - - - - - - - - - - - - - -
#1
#2
Date of Exam Time of Exam I.
Absence of Confounding Factors A. Systolic blood pressure> 90 mm Hg B. Temperature> 32 C0 C. No central nervous depressants (e.g., anesthetics, sedatives, narcotics, alcohol) or neuromuscular blocking agents D. No uremia, meningoencephalitis, hepatic encephalopathy, or other metabolic encephalopathies
II.
Absence of Cei-ebral and Brainstem Function A. Unresponsiveness to painful stimuli (e.g., supraorbital) B. No spontaneous muscular movements, posturing, or seizures C. Pupils light-fixed D. Absent corneal reflexes E. Absent response to upper and lower airway stimulation F. Absent oculocephalic reflexes G. Absent oculovestibular reflexes (ice water calorics) H. No increase in heart rate after IV atropine 2 mg 1. Heart rate before atropine 2. Heart rate after atropine I. Apnea (at PaC0 2 > 60 mm Hg) l. Paco 2 at end of apnea test
m.
Confirmatory Tests
A. B.
IV,
Comments: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __
CERTIFICATION OF DEATH
Having considered the above findings, we hereby certify the death of: Name: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _-==----c=-=--=--------------Date: ________________Time of Death: _ _ _ _ _ _ _ _ _ _ __ Physicians' Signatures MD_ _ _ _ _ _ _ _ _ _----:MD Names Printed ------------=-MD MD Figure 1
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Checklist for clinical diagnosis of brain death.
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organ support will continue after pronouncement of death until the donated organs have been removed. When the coroner has jurisdiction over the body of the deceased, as in a homicide or motor vehicle crash, the coroner's consent must be obtained for removal of organs for transplantation.
Controversial Issues Related to Brain Death It is beyond the scope of this article to review
all the issues related to brain death. The debate over the definition of death continues with addition of cerebral cortical or higherbrain death criteria based on the irreversible loss of cognitive function that is essential to personhood. 3• rn, 30 · 32 Another ethical issue is organ donation involving anencephalic infants who are born without a cerebral cortex but cannot be declared brain dead with an intact brain stem. z, 7
Family In critical care, nursing includes the dying patient and the grieving family. Physicians and nurses acknowledge that there are few things more difficult than speaking with a family about brain death and organ donation. This family is in crisis and they need information, support, comfort, and a private area to meet with health care professionals. The suggestions of numerous researchers and clinicians include providing the family with frequent and current patient status information, presenting clear and concise statements from a limited number of health care providers, and providing time for family questions. Brain death can be a difficult concept for a family to understand, particularly in a highly charged emotional situation. It is essential to assess the family's comprehension of brain death because the patient appears to be breathing and the cardiac monitor continues to show a heartbeat. Health care providers can also use visual aids, such as simple drawings, educational materials, or descriptions of the results of the clinical tests. Death is a medical determination ;lnd the family should not be asked to be a partner in the decision to withdraw mechanical support or monitoring equipment. It is also not appropriate to dis-
cuss organ donation until the family understands that death has occurred. It is important to provide a delay, or decouple the death from the request for donation. 8
Organ Donation In January 2000, 66,067 patients were on the United Network for Organ Sharing (UNOS) National Patient Waiting List, and this list grows by 500 each month. 31 Ten people die every day in the United States while waiting for organ donation. 31 The need for donor organs has increased with improving success rates for organ transplant surgery, changing eligibility requirements, and the proliferation of transplants. Age limits for recipients have increased and diabetes or alcohol-related liver failure is no longer a contraindication. At the same time, the number of organ donors has shown little growth and successful safety measures (e.g., speed limits, seat belts, air bags, and designated drivers) have reduced the number of deaths in which organ donations might have been possible. In 1998, the number of cadaveric donors was 5799, although it has been estimated that there were more than 12,000 potential donors. 31 The current system of organ donation relies on the ethical principles of voluntarism and altruism. Voluntariness is consistent with respecting individual autonomy and respect for dignity after death. Altruism is the desire to help others. 16• 28 The focus is on the individual's prior consent to donate, including a donor card or documentation on a driver's license, but family consent is also obtained. There is also activity in the legislative arena. The Omnibus Budget Reconciliation Act of 1986 (Public Law 99-509) states that health care institutions that received Medicare must have written policies that give families of potential donors the right to be offered the option of organ and tissue donation. The Pennsylvania Act 102 in 1994 mandated that a routine referral system be established by all Pennsylvania acute care hospitals. Hospitals must notify the regional Organ Procurement Organization (OPO) of all deaths or impending deaths, then the OPO works with the medical team to evaluate the potential for donation.4 The Health Care Financing Administration (HCFA) established a routine notification pol-
BRAif\I DEATH .l\ND ORGAN DONATION
that became effective August 2l, 1998, with the issue of Hospital Conditions of Particfor Medicare ancl Medicaid. These regulations require all acute care hospitals to notify the appropriate OPO in a timely manner regarding imminent deaths or deaths in the hospital setting.<' The two most limiting factors in organ donation today are (1) failure to determine which patients are potential organ donors and lack of referral of those patients to the organ procurement organization and (2) refusal of patients' families to consent to donation. 0 8· 9 11 Recent studies have looked at variables that affect organ donation rates. These situational and demographic factors include the following: 1. Confusion about brain death in both health professionals and families 8 2. Staff preparedness to handle organ donation8 3. The timing of the request to provide a delay or decouple the death from the request for donation 8
Ii.
who shoc.ilcl
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5.
members of patients less than 50 years old more likely to donate than family members of patients more than 60 years olcl 8 6. Cause of death, with rates of donation higher for trauma patients than nontrauma patients 12 7. Racial and cultural demographics, with African-Americans less likely to clonate 12 Recommendations to improve organ donation rates as well as staff and family satisfaction are based on addressing the key issues of when to approach, where to approach, and who is involved in the approach. 8 Referral begins with routine notification of all hospital deaths and early referral of all brain-injured patients to the OPO. The family needs a private setting for ongoing communication with the physician and nursing staff. Allow the family time to accept death before introducing a request for organ donation, then introduce the OPO representative to the fan1ily to request consent at an appropriate time. 8
Critical care nurses are essential team members during the process of determining brain death and preparing for organ donation. Using their knowledge of the criteria for brain death, they care for the dying patient, support the grieving family, and participate in the consent process for organ donation. Nurses make a critical difference in saving the lives of others through the gift of life.
REFERENCES 1. Bec:cher I !KA: Definition of irreversible coma. Report
2.
3. 4.
5.
6.
of the Ad Hoc Committee of the Harvard Medical School to examine the: definition of brain death.JA.!v!A 205:337-340. 1968 Cady R: Anencephalics as organ donors: \Vhere do we stand? Amc:rican journal of Maternal/Child Nursing 24:51-52, 1999 Cranford R: Even the dead are not terminally ill anymore. Neurnlogy 51:1530-1531. 1998 Center for Organ Recove1y and Education (CORE): Legislative issues and news. Pittsburgh. PA. Available at: http:/hvww.core.org. Accessed January 12, 2000 Dc:Jong W, Franz HG, Wolfe SM, et al: Requc:sting organ donation: An interview study of donor and nonclonor families. Am] Crit Care 7: 13-23, 1998 Departmc:nt of Health anrl I i1,1n:•n Services, Health Care Financing Administration (I-!CFA). (June 22. 1998): Medicare and Medicaid programs; Hospital conditions of participation; Identification of potential
7.
8.
9.
10. 11.
12.
organ. tissue and eye donors. \Vashington, DC. Available at: http://ww1v.organdonor.gov. AccessedJanuaiy 12, 2000 Diaz JI-!: The: anencephalic organ donor: A challenge to existing moral and statutory laws. Crit Care Med 21:1781-1786, 1993 Ehrle RN, Shafer RJ, Nelson KR: Eeferral, request. and consc:nl for organ donation: Best Practice-a blueprint for success. Critical c~1re Nurse 19:21-33. 1999 Evanisko Mj, Beasley CL, Brigham LE. et al: Readiness of critical care physicians and nurses to handle: requests for organ donation. Am] Crit Care 7:4-12, 1998 Fisher CM: Brain death-a review of the concept. J Neurosci Nurs 23:330-:333, 1988 Franz I-IG, DeJong W, Wolfe SM, et al: Explaining brain death: A critical feature of the donation process. Journal of Transplant Coordination 7:11-21, 1997 Gortmaker SL, Beasley CL, Brigham LE: Organ donor potential and performance: Size and nature of thlo organ donor shortfall. Crit Care Med 21:432-439. 1996
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13. Hickey JV: Diagnostic procedures and laboratory tests for neuroscience patients. In The Clinical Practice of Neurological and Neurosurgical Nursing, ed 4. Philadelphia, Lippincott, 1997, pp 81-101 14. Hughes R, McGuire G: Neurologic disease and the determination of brain death: The importance of a diagnosis. Crit Care Med 25: 1923-1924, 1997 15. Kaufman HH, Brick], Frick M: Brain death. In Youmans JR Ced): Neurological Surgery, eel 4. Philadelphia, WB Saunders, 1996, pp 439-451 16. Klassen AC, Klassen DK: Who arethe donors in organ donation? The family's perspective in mandated choice. Ann Intern Med 125:70-73, 1995 17. Medical Consultants on the Diagnosis of Death to the President's Commission for the Study of Ethical Problems in Medicine and Biomedical and Behavioral Research. Report: Guidelines for the determination of death. JAMA 246:2184-2186, 1981 18. Ott BB: Defining and redefining death. Am] Crit Care 4:476-480, 1995 19. Pernick MS: Back from the grave: Recurring controversies over defining and diagnosing death in history. In Zanner RM (ed): Death: Beyond Whole-Brain Criteria. Boston, Kluwer Academic, 1988, pp 17-74 20. Practice parameters for determining brain death in adults summary statement. American Academy of Neurology. Neurology 45:1012-1014, 1995 21. President's Commission for the Study of Ethical Problems in Medical and Biomedical and Behavioral Research: Defining death. Washington, DC, US Government Printing Office, 1981
22. President's Commission for the Study of Ethical Problems in Medical and Biomedical and Behavioral Research: Summing up. Washington, DC, US Government Printing Office, 1983 23. Reilly PM, Alavi A, Jenkins DH: Imaging the brain. N Engl J Med 339:407-409, 1998 24. Reuler JB: Hypothermia: Pathophysiology, clinical settings and management. Ann Intern Med 89:519527, 1978 25. Report of the Medical Consultants on the Diagnosis of Death. Guidelines for the determination of death. JAMA 246:2184-2186, 1981 26. Rudy EB: Brain death. In Clouchesy JM, Breu C, Cardin S, et al (eds): Critical Care Nursing, eel 2. Philadelphia, WB Saunders, 1996, pp 803-811 27. Selby R: Brain death. In Wilkins RH, Rengachary SS (eds): Neurosurgery, ed 2. New York, McGraw-Hill, 1996, pp 4231-4251 28. Siminoff LA, Arnold RN, Caplan AL, et al: Public policy governing organ and tissue procurement in the United States: Results from the National Organ and Tissue Procurement study. Ann Intern Med 123:1017, 1995 29. Sullivan J, Seem DL, Chabalewski F: Determining brain death. Critical Care Nurse 19:37-46, 1999 30. Taylor RM: Reexamining the definition and criteria of death. Semin Neurol 17:265-270, 1997 31. United Network for Organ Sharing (UNOS): US facts about transplantation. Available at: http://www. unos.org. Accessed January 15, 2000 32. Williams MA, Suarez JI: Brain death determination in adults: More than meets the eye. Crit Care Med 25: 1787-1788, 1997
Address reprint requests to Darlene Lovasik, MN, RN, CCRN, CNRN 1118 Galaxy Circle Pittsburgh, PA 15241
Brain Death and Organ Donation Darlene Lovasik, MN, RN, CCRN, CNRN
Critical care nurses and physicians work to delay death every day; however, when one asks these health care providers for the definition of death, the diverse answers include physiologic, legal, religious, and moral descriptions. Defining death is not as clear as it was in the past, and changes in the definition of death have been driven by advances in organ transplantation. One of the primary reasons for determining brain death is to ascertain if the patient is a potential organ donor. By recognizing the process of death, surgeons are able to recover transplantable organs. Other improvements in organ transplant surgery, immunology, and pharmacology, particularly the use of cyclosporin and other antirejection drugs, have saved and prolonged the lives of the organ recipients. Because of the biomedical advances of the past 40 years, patients surviving catastrophic events are connected to mechanical devices that sustain their lives, even without evidence of cerebral activity. Hospitals use established guidelines for the clinical diagnosis of brain death, then follow procedures for brain death certification. The primary causes of brain death are head trauma, particularly motor vehicle crashes and gunshot wounds, and cerebral hemorrhage.
From the University of Pittsburgh Hccalth System, Pittsburgh. Pennsylvania
Most people would describe death as the cessation of cardiac and pulmonary activity or heart-lung death. One funeral custom that continues today began as a process to determine death. After preparing a deceased person for burial, family and friends gathered together to eat and wait to see if the departed would wake up. "Wakes" continue to be observed today. The fear of being buried alive continued in England during the Middle Ages. The departed had a string tied to his or her wrist that went through the coffin, up through the ground, and tied to a bell. Someone would sit in the graveyard at night to listen to the bell, so on the graveyard shift, they would know that someone was "saved by the bell" or was a "dead ringer." Coffins with breathing tubes could be purchased in Germany in the late 19th century. 19 Other means of determining death included checking for respiration by using a candle or mirror, testing the nervous system through the use of smelling salts or a trumpet, and evaluating the circulation via bleeding. 15 20 With the introduction of mechanical ventilation, a new clinical condition was noted. Coma depasse or state beyond coma was first described in 1959 in France. 10 In 1967, Dr. Christian Bernard in South Africa performed the first human-to-human heart transplant. Although the donor may have met the criteria
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now used for brain death, she was removed from life support and became asystolic, and retrieval of the heart did not begin until 12 minutes after she had been declared dead. This controversial situation ignited medical, legal, moral, and ethical debate that continues today.
Criteria for Brain Death Anticipating further experimentation using cadaver organs, the Harvard Ad Hoc Committee on Irreversible Coma met in 1968 and published the first guidelines for establishing brain death in the Journal of the American Medical Association in August 1968. 1This was followed in 1970 by the Determination of Death Act in Kansas. In 1981, the President's Commission for the Study of Ethical Problems in Medicine and Biomedical and Behavior Research stated that criteria for brain death should include the following documentation: 1. The condition of the patient is irreversible and must have a known cause. 2. Cerebral and brain stem functions are absent. 3. Cessation of all brain functions has persisted through a period of observation.17, 21, 21 The President's Commission defined death as either the irreversible cessation of function of the heart and lungs or irreversible loss of all functions of the entire brain. This is significant because it states that brain death is not a different type of death but is equivalent to heartlung death. Since 1981, all 50 states have recognized the Uniform Determination of Death Act: 1. An individual who has sustained either: (1) irreversible cessation of circulatory and respiratory functions or (2) irreversible cessation of all functions of the entire brain, including the brain stem, is dead. A determination of death shall be made in accordance with accepted medical standards. 2. The irreversible loss of all brain function: (1) the cerebral hemispheres with loss of cognitive function and (2) the brain stem with loss of respiratory and circulatory activities. 17 · 21 · 22 · 24
Clinical Criteria for Brain Death Before making a clinical diagnosis of brain death, the cause of the patient's coma must
be established. Clinical or neuroimaging evidence must explain the irreversible cessation of all brain function. Factors other than primary brain injury that may impair brain function must be absent. The following complicating medical conditions should be excluded: (1) shock, (2) hypothermia, (3) absence of central nervous system depressants, (4) metabolic abnormality, and (5) correctable abnormalities. One of the primary signs of shock is a decreased level of consciousness as a result of reduced cerebral perfusion. The patient's blood pressure should be at least 90 mm Hg systolic or no greater than 10 mm Hg below the patient's usual systolic pressure with evidence of adequate tissue perfusion to exclude shock as the cause of a decreased level of consciousness. Hypothermia also drastically diminishes both cerebral blood flow and oxygen requirements. Although is it unusual, victims who appear to be clinically dead because of marked depression of brain and cardiovascular function may be resuscitated. Therefore, the core body temperature must be at least 32°C before declaring death. "No one is dead until they are warm and dead." 25 A substantial dose of central nervous system (CNS) depressants can also mimic brain death. When drugs are implicated as a possible cause or contributory factor in the comatose patient, or in a patient with a coma of unknown cause, toxicologic screening and analysis are required. This includes sedatives and anesthetics such as barbiturates, benzodiazepines, meprobamate, and alcohol. If neuromuscular blocking agents such as succinylcholine or vecuronium have been used, normal neuromuscular transmission is determined by using a nerve stimulator to evaluate function. Patients who have received recent general anesthesia must be observed for a sufficient period to allow for the elimination of the anesthetic based on the pharmacology of the agent. If the blood levels of CNS depressants are in the therapeutic or toxic range or if the blood alcohol level is equal to or greater than 100 mg/ dL, the patient cannot be declared brain dead without a confirmatory test an absence of blood flow to the brain. Patients with alcohol levels less than 100 mg/ dL or CNS depressant levels in the subtherapeutic range may be declared brain dead only when the patient has suffered an
BR/l,!f\1 DEATH AND ORGAN DONATION
obvious lethal brain injury as indicated clinical examination and supported by CT scanning blunt head injury with massive brain swelling and herniation or bihemispheric gunshot wounds). Both alcohol and CNS depressants must be absent to declare brain death in the patient with an unknown cause of coma. Metabolic abnormalities should be absent including electrolyte abnormalities, acidbase disturbances, or endocrine disturbances that are known to impair brain function (e.g., hepatic encephalopathy, hyperosmolar coma, severe uremia, or hypothyroidism). Finally, the patient undergoes a period of observation after treatment for potentially correctable abnormalities such as hypoxemia, hypotension, hypovolemia, hypothermia, and severe electrolyte disturbances before beginning an evaluation of brain death. i. P. 20-n 24
Clinical Brain Death Examination The clinical examination for brain death establishes the absence of cerebral and brain stem functions. Evaluation of the cerebral cortex begins by confirming unresponsiveness, a lack of verbal response, lack of coordinated eye movements, and an absence of motor activity, including decorticate and decerebrate posturing. Spontaneous motor activity, shivering, seizures, or any response to painful stimuli must be absent. JS. 26 · 27 · 29 The remainder of this assessment determines brain stem function. The pupillary response demonstrates function of cranial nerves II and III. The pupils should be nonreactive to light stimulation. This reflex may be unreliable after the use of cocaine, opiates, scopolamine, atropine, dopamine, or mydriatic eye drops or in the patient with eye trauma or disease, including cataracts. 15 · 2<' 27 • 29 The two ocular movements evaluated are the oculocephalic (doll's eyes) and oculovestibular (ice-water calorics) responses. The oculocephalic reflex illustrates function of cranial nerves III, VI, and VIII and is tested by rapidly turning the head laterally from rniclposition to 90° on both sides. The normal response (with an intact brain stem) is for the eyes to move opposite to the head turning. If the reflex is absent, the eyes will remain fo1ward with rapid head turning. Testing the oculocephalic reflex is contraindicated in the patient with a known or suspected cervical spinal inju1y. Ji. 26 · 29
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The oculovestibular reflex is controlled cranial nerves III and VIII and is tested by the irrigation of at least 50 mL of ice-cold water or saline into each external auditory canal with the patient's head elevated to 30°. The patient must be observed for any movement of the eyes. With an intact brain stem, the eyes will slowly move toward the irrigated ear. If the cortex is still functioning, this may be followed by rapid nystagmus in the opposite direction. An absent response reveals that the brain stem is no longer functioning. 10 Wait 5 minutes before injecting into each ear. Blood and cerumen in the ears, sedatives, anticholinergics, and ototoxic antibiotics may abolish this reflex. The corneal reflex measures the function of cranial nerves V and VII. The patient should have no facial grimacing to painful stimuli and the corneal reflex, tested by using a cottontippecl swab, should be absent. JS. 26 · 27 · 29 The gag or cough reflex is controlled by cranial nerves IX and X. The gag reflex should be absent with pharyngeal stimulation, and the patient should not cough following deep tracheal suctioning. 1'· 26 · 27 · 29 Atropine is used to assess the status of vagus nerve, cranial nerve X. Following a dose of atropine, 2 mg IV bolus, the heart rate should increase. If the vagus nerve nuclei is not responsive, less than a 5 beat per minute (bpm) response follows the injection. Apnea testing is based on evidence that carbon dioxide is the strongest stimulus for spontaneous respiration. Because the brain stem is responsible for sensing and responding to changes in Paco 2 (partial pressure of dissolved carbon dioxide) and pH, apnea is the result of a nonfunctioning brain stern. Spontaneous breathing or any evidence of respiratory effort must be absent while the ventilator is discontinued. The patient is provided 100% oxygen (OJ through the ventilator in the continuous positive airway pressure (CPAP) mode or through an oxygen cannula placed down the enc.lotracheal tube to the level of the carina with oxygen delivered at a minimum of 6 L/min. If the arterial Pco 2 increases to 60 mm Hg or greater or with an increase in Pco 2 of at least 20 mm Hg above the patient's normal Pco 2 without a respiratory response, it is evidence that the brain stem has ceased to function. Arterial blood gases (ABGs) are measured to document both Pao 2 and Paco 2 levels. There may be complications
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associated with apnea testing, including hypotension and cardiac dysrhythmias. 15 • 27 · 29
Adjunctive Tests The following tests are recommended when severe metabolic abnormalities such as uremia, hepatic encephalopathy, or other metabolic encephalopathies are present; apnea testing cannot be performed; when the primary brain insult is infratentorial; or when the cause of brain death is uncertain or is due to global ischemia or anoxic injury. These adjunctive tests can be performed at the bedside. A single 16- or 18-channel electroencephalogram (EEG) should demonstrate electrocerebral silence for at least 30 minutes of recording. It is recommended that a neurologist using the guidelines developed by the American Electroencephalographic Society makes the interpretation of the EEG. Because an EEG evaluates the cerebral cortex only, and not the function of the brain stem, it is not mandatory for confirming brain death. 20 A transcranial doppler can be used over the intracranial arteries to determine absent diastolic or reverberating flow, small systolic peaks, or absent signals in an unresponsive patient. This is particularly useful with the patient who previously had transcranial doppler signals. is, 26 · 27 • 29 Somatosensory evoked potentials (SSEPs) are used to measure bilateral median nerve stimulation. SSEPs and Brain Stem Auditory Evoked Responses (BAERs) will be absent in the brain-dead patient. is, 26 · 27 · 29 Sustained increased intrancranial pressure (ICP) within 10 to 20 mm Hg of the mean arterial pressure (MAP) is also a poor prognostic sign.
Confirmatory Tests Confirmatory tests that demonstrate absent cerebral blood flow are performed to verify clinical brain death examination when the patient examination is confounded by drug or alcohol intoxication, neuromuscular blockade, or hypothermia. They generally require transporting the patient to the diagnostic procedure area. Four-vessel (carotid and vertebral contrast cerebral angiogram will reveal absent intracranial filling at the level of the carotid bifurcation or circle of Willis.
Xenon cerebral blood flow (CBF) studies using either radioactive or stable xenon should demonstrate mean cerebral blood flow of less than 5 mL/100 g/min (normal is 50 mL/100 g/min) to authenticate brain death. Cranial radionuclide angiography using technetium 99m should demonstrate absent supratentorial flow. 23 The PET scanner measures cerebral metabolism, but the cost and limited availability of this technology makes this prohibitive at this time. 15 • 26· 27
Special Concerns It is recognized that there are some situations
that may require further testing. Spinal reflexes may produce movement of some muscle groups, and the origin of this activity should be verified by cerebral blood flow studies. The patient should not exhibit an autonomic response to pain, such as a change in pulse or blood presure. Finally, an EEG with random electric activity cannot be used to determine brain death. A few cerebral functions such as temperature regulation and anterior and posterior pituitary function continue following the diagnosis of brain death. Questions may also arise in patients with minimal cerebral blood flow or some preserved brain stem function. 14• is, 29
Brain Death in Pediatrics Guidelines have been established for the determination of brain death in infants and young children. These guidelines differ from the guidelines established for adults. The immature brain may be viable despite the absence of EEG activity or other classic determinants of brain death; therefore, a longer period of observation is recommended. For neonates, life support is continued until at least 7 days of age. The observation period recommended for infants 7 to 60 days of age is 48 hours; for infants 61 days to 12 months old, 14 hours; and for children over 1 year of age, 12 hours. 15 • 29
Certification of Death After the clinical examination and recommended diagnostic tests have been completed and the results show no evidence of
BRAIN DEATH AND ORGAN DONATION
continuing brain the patient is certified dead. A few states specify which medical specialties are permitted to declare brain death. Many institutions require two separate clinical examinations with an interval of 2 to 6 hours or examination by two physicians demonstrating complete absence of all brain function for certification of brain death. It is recommended that members of the transplantation team not be involved in the death certification of a brain-dead organ donor.
hospitals use a form for brain death certification that is completed by the physicians (Fig. 1). Brain death certification is equivalent to the traditional pronouncement of death, and the time of death documented for this certification is the time of death to be used for all legal documents. Life support may be withdrawn following certification and pronouncement of brain death except when the deceased is an organ donor. Cardiopulmonary and other essential
Clinical Evaluations C:mse of Brain D e a t h - - - - - - - - - - - - - - - - - -
#1
#2
Date of Exam Time of Exam I.
Absence of Confounding Factors A. Systolic blood pressure> 90 mm Hg B. Temperature> 32 C0 C. No central nervous depressants (e.g., anesthetics, sedatives, narcotics, alcohol) or neuromuscular blocking agents D. No uremia, meningoencephalitis, hepatic encephalopathy, or other metabolic encephalopathies
II.
Absence of Cei-ebral and Brainstem Function A. Unresponsiveness to painful stimuli (e.g., supraorbital) B. No spontaneous muscular movements, posturing, or seizures C. Pupils light-fixed D. Absent corneal reflexes E. Absent response to upper and lower airway stimulation F. Absent oculocephalic reflexes G. Absent oculovestibular reflexes (ice water calorics) H. No increase in heart rate after IV atropine 2 mg 1. Heart rate before atropine 2. Heart rate after atropine I. Apnea (at PaC0 2 > 60 mm Hg) l. Paco 2 at end of apnea test
m.
Confirmatory Tests
A. B.
IV,
Comments: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __
CERTIFICATION OF DEATH
Having considered the above findings, we hereby certify the death of: Name: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _-==----c=-=--=--------------Date: ________________Time of Death: _ _ _ _ _ _ _ _ _ _ __ Physicians' Signatures MD_ _ _ _ _ _ _ _ _ _----:MD Names Printed ------------=-MD MD Figure 1
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Checklist for clinical diagnosis of brain death.
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organ support will continue after pronouncement of death until the donated organs have been removed. When the coroner has jurisdiction over the body of the deceased, as in a homicide or motor vehicle crash, the coroner's consent must be obtained for removal of organs for transplantation.
Controversial Issues Related to Brain Death It is beyond the scope of this article to review
all the issues related to brain death. The debate over the definition of death continues with addition of cerebral cortical or higherbrain death criteria based on the irreversible loss of cognitive function that is essential to personhood. 3• rn, 30 · 32 Another ethical issue is organ donation involving anencephalic infants who are born without a cerebral cortex but cannot be declared brain dead with an intact brain stem. z, 7
Family In critical care, nursing includes the dying patient and the grieving family. Physicians and nurses acknowledge that there are few things more difficult than speaking with a family about brain death and organ donation. This family is in crisis and they need information, support, comfort, and a private area to meet with health care professionals. The suggestions of numerous researchers and clinicians include providing the family with frequent and current patient status information, presenting clear and concise statements from a limited number of health care providers, and providing time for family questions. Brain death can be a difficult concept for a family to understand, particularly in a highly charged emotional situation. It is essential to assess the family's comprehension of brain death because the patient appears to be breathing and the cardiac monitor continues to show a heartbeat. Health care providers can also use visual aids, such as simple drawings, educational materials, or descriptions of the results of the clinical tests. Death is a medical determination ;lnd the family should not be asked to be a partner in the decision to withdraw mechanical support or monitoring equipment. It is also not appropriate to dis-
cuss organ donation until the family understands that death has occurred. It is important to provide a delay, or decouple the death from the request for donation. 8
Organ Donation In January 2000, 66,067 patients were on the United Network for Organ Sharing (UNOS) National Patient Waiting List, and this list grows by 500 each month. 31 Ten people die every day in the United States while waiting for organ donation. 31 The need for donor organs has increased with improving success rates for organ transplant surgery, changing eligibility requirements, and the proliferation of transplants. Age limits for recipients have increased and diabetes or alcohol-related liver failure is no longer a contraindication. At the same time, the number of organ donors has shown little growth and successful safety measures (e.g., speed limits, seat belts, air bags, and designated drivers) have reduced the number of deaths in which organ donations might have been possible. In 1998, the number of cadaveric donors was 5799, although it has been estimated that there were more than 12,000 potential donors. 31 The current system of organ donation relies on the ethical principles of voluntarism and altruism. Voluntariness is consistent with respecting individual autonomy and respect for dignity after death. Altruism is the desire to help others. 16• 28 The focus is on the individual's prior consent to donate, including a donor card or documentation on a driver's license, but family consent is also obtained. There is also activity in the legislative arena. The Omnibus Budget Reconciliation Act of 1986 (Public Law 99-509) states that health care institutions that received Medicare must have written policies that give families of potential donors the right to be offered the option of organ and tissue donation. The Pennsylvania Act 102 in 1994 mandated that a routine referral system be established by all Pennsylvania acute care hospitals. Hospitals must notify the regional Organ Procurement Organization (OPO) of all deaths or impending deaths, then the OPO works with the medical team to evaluate the potential for donation.4 The Health Care Financing Administration (HCFA) established a routine notification pol-
BRAif\I DEATH .l\ND ORGAN DONATION
that became effective August 2l, 1998, with the issue of Hospital Conditions of Particfor Medicare ancl Medicaid. These regulations require all acute care hospitals to notify the appropriate OPO in a timely manner regarding imminent deaths or deaths in the hospital setting.<' The two most limiting factors in organ donation today are (1) failure to determine which patients are potential organ donors and lack of referral of those patients to the organ procurement organization and (2) refusal of patients' families to consent to donation. 0 8· 9 11 Recent studies have looked at variables that affect organ donation rates. These situational and demographic factors include the following: 1. Confusion about brain death in both health professionals and families 8 2. Staff preparedness to handle organ donation8 3. The timing of the request to provide a delay or decouple the death from the request for donation 8
Ii.
who shoc.ilcl
537 the
5.
members of patients less than 50 years old more likely to donate than family members of patients more than 60 years olcl 8 6. Cause of death, with rates of donation higher for trauma patients than nontrauma patients 12 7. Racial and cultural demographics, with African-Americans less likely to clonate 12 Recommendations to improve organ donation rates as well as staff and family satisfaction are based on addressing the key issues of when to approach, where to approach, and who is involved in the approach. 8 Referral begins with routine notification of all hospital deaths and early referral of all brain-injured patients to the OPO. The family needs a private setting for ongoing communication with the physician and nursing staff. Allow the family time to accept death before introducing a request for organ donation, then introduce the OPO representative to the fan1ily to request consent at an appropriate time. 8
Critical care nurses are essential team members during the process of determining brain death and preparing for organ donation. Using their knowledge of the criteria for brain death, they care for the dying patient, support the grieving family, and participate in the consent process for organ donation. Nurses make a critical difference in saving the lives of others through the gift of life.
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13. Hickey JV: Diagnostic procedures and laboratory tests for neuroscience patients. In The Clinical Practice of Neurological and Neurosurgical Nursing, ed 4. Philadelphia, Lippincott, 1997, pp 81-101 14. Hughes R, McGuire G: Neurologic disease and the determination of brain death: The importance of a diagnosis. Crit Care Med 25: 1923-1924, 1997 15. Kaufman HH, Brick], Frick M: Brain death. In Youmans JR Ced): Neurological Surgery, eel 4. Philadelphia, WB Saunders, 1996, pp 439-451 16. Klassen AC, Klassen DK: Who arethe donors in organ donation? The family's perspective in mandated choice. Ann Intern Med 125:70-73, 1995 17. Medical Consultants on the Diagnosis of Death to the President's Commission for the Study of Ethical Problems in Medicine and Biomedical and Behavioral Research. Report: Guidelines for the determination of death. JAMA 246:2184-2186, 1981 18. Ott BB: Defining and redefining death. Am] Crit Care 4:476-480, 1995 19. Pernick MS: Back from the grave: Recurring controversies over defining and diagnosing death in history. In Zanner RM (ed): Death: Beyond Whole-Brain Criteria. Boston, Kluwer Academic, 1988, pp 17-74 20. Practice parameters for determining brain death in adults summary statement. American Academy of Neurology. Neurology 45:1012-1014, 1995 21. President's Commission for the Study of Ethical Problems in Medical and Biomedical and Behavioral Research: Defining death. Washington, DC, US Government Printing Office, 1981
22. President's Commission for the Study of Ethical Problems in Medical and Biomedical and Behavioral Research: Summing up. Washington, DC, US Government Printing Office, 1983 23. Reilly PM, Alavi A, Jenkins DH: Imaging the brain. N Engl J Med 339:407-409, 1998 24. Reuler JB: Hypothermia: Pathophysiology, clinical settings and management. Ann Intern Med 89:519527, 1978 25. Report of the Medical Consultants on the Diagnosis of Death. Guidelines for the determination of death. JAMA 246:2184-2186, 1981 26. Rudy EB: Brain death. In Clouchesy JM, Breu C, Cardin S, et al (eds): Critical Care Nursing, eel 2. Philadelphia, WB Saunders, 1996, pp 803-811 27. Selby R: Brain death. In Wilkins RH, Rengachary SS (eds): Neurosurgery, ed 2. New York, McGraw-Hill, 1996, pp 4231-4251 28. Siminoff LA, Arnold RN, Caplan AL, et al: Public policy governing organ and tissue procurement in the United States: Results from the National Organ and Tissue Procurement study. Ann Intern Med 123:1017, 1995 29. Sullivan J, Seem DL, Chabalewski F: Determining brain death. Critical Care Nurse 19:37-46, 1999 30. Taylor RM: Reexamining the definition and criteria of death. Semin Neurol 17:265-270, 1997 31. United Network for Organ Sharing (UNOS): US facts about transplantation. Available at: http://www. unos.org. Accessed January 15, 2000 32. Williams MA, Suarez JI: Brain death determination in adults: More than meets the eye. Crit Care Med 25: 1787-1788, 1997
Address reprint requests to Darlene Lovasik, MN, RN, CCRN, CNRN 1118 Galaxy Circle Pittsburgh, PA 15241