The Determination of Brain Death James Zisfein, M.D. Chief, Division of Neurology Lincoln Medical Center, Bronx, NY James.Zisfein@nychhc.org
The early history of brain death Until recently, death was determined only when the heart stopped. Heart stoppage was irreversible and also stopped all other organs. In total brain failure, breathing also stopped, which stopped the heart. Heart stoppage was an easily assessed marker for death. No need to choose which organ is the source of life, except in Talmudic arguments. Enter the positive-pressure ventilator and other critical care measures. The ventilator was lifesaving in reversible pulmonary conditions, but when used in brain failure, there were unanticipated outcomes. Neurology: a condition beyond coma EEG: electrocerebral silence Pathology: liquefaction necrosis of the brain How do we determine when death occurs when we block the usual signs?
Published guidelines Harvard Criteria (1968) President's Commission Criteria (1981) American Academy of Pediatrics (1987) American Academy of Neurology (1995, 2010) New York State Department of Health (2005, 2011) This presentation is based on guidelines of the AAN (2010) and NYSDOH (2011) All of these guidelines are 100% specific Despite aggressive treatment, a patient who is found to be brain dead never regains any brain functions
Definition Brain death is the irreversible loss of all brain functions "Functions" are clinically ascertainable, e.g., animation and respiration Generation of electrical activity, cerebral blood circulation, and metabolism are not brain functions A person who is brain dead is dead according to standards of medical practice and the law in all US jurisdictions This is not optional However, reasonable accommodations can be made to support the family in case of religious or moral objections The time of death is the time that this determination is made (usually at the conclusion of an apnea test) It is not sometime later when the heart stops
The brain death evaluation Begin the evaluation when the patient Is unresponsive Has unreactive pupils Requires a ventilator When the evaluation begins, make 3 calls: Inform the next-of-kin or surrogate decision-maker. If that person is unknown or unreachable, get help from hospital administration. Call your regional organ procurement organization (OPO). You must do this even if the patient will not be an organ donor. Obtain consultation from a brain death expert. Requirements for privileging vary by institution.
The diagnosis of brain death in 5 easy steps 1. The cause of brain failure is irreversible. 2. The patient is unresponsive. 3. Brainstem reflexes are absent. 4. An apnea test shows no breathing. 5. Ancillary tests are not required unless the clinical diagnosis is uncertain. Note: the guidelines are different for diagnosis of brain death in infants under 1 year of age.
1. Brain failure is irreversible Most brain deaths occur from Severe brain trauma Massive stroke (usually hemorrhage) Prolonged cardiac arrest Sufficient time has elapsed to ensure irreversibility Post-cardiac arrest, 6 hours is a reasonable interval Absence of cerebral blood flow (on a CBF test) also documents an irreversible process.
2. The patient is unresponsive We're talking here about cerebral unresponsiveness. Grimacing and other cranial-nerve responses are absent (except for CN XI). Spinal reflexes (including spinal withdrawal ) can be present. Less common spinal movements include: Fragments of decerebrate posturing (including neck extension) The undulating toe or finger sign Lazarus sign
3. Brainstem reflexes are absent Pupillary light reflex Pupils should be mid-position or large Vestibulo-ocular reflex (eye movements) Doll's eyes and ice-water calorics Corneal reflex Gag and cough reflex Response to suctioning
4. An apnea test shows no breathing Prerequisites: normal PaCO 2 and absence of respiratory depressants (CNS or peripheral), hypotension (SBP<100), or hypothermia (<36ºC). If the OPO or family has not yet been notified, please do so now! Test for apnea even if patient is overbreathing the ventilator. Obtain pre-test PaCO 2, preoxygenate, then remove ventilator for 8-10 minutes while giving O 2 by tracheal cannula. Observe closely for breathing. Monitor BP and O 2 saturation continuously. The apnea test confirms brain death if the end-of-test PaCO 2 is 60 mmhg (or, 20 mmhg above pre-test PaCO 2 ). If the apnea test cannot be completed, repeat it with better patient preparation, or do a cerebral blood flow test.
5. Ancillary tests Are not required unless the clinical diagnosis of brain death is uncertain. The most commonly performed tests are serum chemistry and toxicology and CT scan of the brain. CT can be normal post-cardiac arrest. Please put ancillary test findings in clinical context! Abnormal chemistry or toxicology does not invalidate a diagnosis of brain death unless the clinical diagnosis is uncertain. Presence of an intoxicant is relevant only if the quantity present would cause intoxication EEG is of very limited value for diagnosis of brain death, however it is mentioned in some pediatric brain death protocols.
5. Ancillary tests (continued) Perform a cerebral blood flow study (catheter angiogram, CTA, MRA, radionuclide study, transcranial doppler) when cranial nerve examination is inhibited by peripheral lesions the apnea test is invalidated by central or peripheral respiratory depressant drugs (you still do the apnea test) the apnea test cannot be completed due to hypotension or hypoxia (do as much of the apnea test as can be done safely) the brain failure is not clearly due to an irreversible process the patient is under the age of 1 year >95% of brain death evaluations do not require a CBF study
One exam or two? Prior to 2010, brain death guidelines specified that the brain death exam had to be performed twice. AAN (1995): suggested 6 hour interval between exams. There was never any evidence supporting this! There are no reports of recovery after a properly performed brain death exam shows no brain functions. Lustbader et al. (2011): 2nd exam unnecessary on 1300 brain death evaluations, also 24-hour delay in diagnosis. AAN 2010, NYSDOH 2011: single exam is sufficient if performed by qualified examiner "several hours" after incident event.
Guidelines for infants <1 year of age Below age 1 year, the observation period should be at least 24 hours, and a confirmatory test should be performed. Below age 2 months, the observation period should be 48 hours. Below age 1 week (and in premature infants), the diagnosis of brain death may be unreliable. (AAP, 1987) Note: more recent pediatric guidelines have been published, but these are problematic and have not received the approval of the AAN.
Brain death in California Brain death is death. The determination of death is made in accordance with accepted medical standards. An independent confirmation is required by a second physician. The physicians determining and confirming death shall not participate in the transplantation of organs or tissues.
Family notification Notify the family (or other qualified surrogate) when a brain death evaluation is initiated. Notify does not mean ask permission. Consent is not required for neurologic examination, apnea testing, or any ancillary tests needed to diagnose death. Stay in communication and make the process transparent. Family members are allowed to be present during the brain death exam and apnea test. Be prepared to answer questions regarding spinal movements. Notify the family again when the declaration of death is made. The OPO Family Services Coordinator should be involved at this time.
Objection to a brain death determination The determination of death must still be made and a declaration of death note must be written. The objection may disappear after your careful explanation. Involve risk management and your clinical ethics consultation service if the objection continues. For objections on a religious or moral basis: reasonable efforts to accommodate the objection must be made. Reasonable may vary by hospital. For objections that are not on a religious or moral basis: New York State guidelines do not require reasonable accommodation and medical support may be removed after discussion with risk management. Being nice is always required.
Reasonable accommodation, California style An acute care hospital shall provide family or next of kin with a reasonably brief period of accommodation from the time that a patient is declared dead by reason of irreversible cessation of all brain functions through discontinuation of cardiopulmonary support. During this reasonably brief period of accommodation, a hospital is required to continue only previously ordered cardiopulmonary support. No other medical intervention is required. For purposes of this section, a "reasonably brief period" means an amount of time afforded to gather family or next of kin at the patient's bedside. A hospital subject to this section shall provide the patient's legally recognized health care decisionmaker, if any, or the patient's family or next of kin, if available, with a written statement of the policy described in subdivision (a), upon request, but no later than shortly after the treating physician has determined that the potential for brain death is imminent. California Health & Safety Code Section 1254.4
Reasonable accommodation, California style If the patient's legally recognized health care decisionmaker, family, or next of kin voices any special religious or cultural practices and concerns of the patient or the patient's family surrounding the issue of death by reason of irreversible cessation of all functions of the entire brain of the patient, the hospital shall make reasonable efforts to accommodate those religious and cultural practices and concerns. For purposes of this section, in determining what is reasonable, a hospital shall consider the needs of other patients and prospective patients in urgent need of care. There shall be no private right of action to sue pursuant to this section. California Health & Safety Code Section 1254.4
Reasonable accommodation, HHC style Reasonable accommodation after the determination of death includes: The continued provision of ventilator support and routine nursing care for a reasonable period (generally not to exceed 72 hours from the time of pronouncement). Reasonable accommodation does not require: Treatment for an indefinite period of time after the determination of death. Performance of diagnostic or therapeutic procedures, e.g., blood tests, radiologic tests, physiologic monitoring, administration of medications for any purpose, nutrition or hydration support, cardio-pulmonary resuscitation (notwithstanding absence of a DNR order), or treatment in a critical care unit. Reference: New York City Health and Hospitals Corporation Corporate Brain Death Policy
Organ donation in brain death Contact your OPO immediately when a brain death diagnosis is considered. Clinical triggers will vary by institution. Contact the OPO even if the patient will not be an organ donor. Brain death determination is not contingent on the possibility of organ donation. Work cooperatively with the transplant coordinator and follow best practices for preservation of organ function. This is best accomplished in a critical care unit. It is ethical to start this before the declaration of death. Avoid discussion of organ donation before death is declared and family is informed.
Why is brain death death? Brain death is death because brain dead patients die soon anyway. This is a logical fallacy. It is not always factually true (e.g., McMath). Brain death is death because of loss of somatic integration. Some brain dead patients can be maintained in a non-critical-care setting. Brain death is death because an individual permanently without any brain function has ceased to be a person. Thought experiment: dismemberment Thought experiment: immortality Brain death is death because it is good public policy. Brain death allows for organ donation without violating the dead donor rule. Brain death allows for termination of medical support without family consent in hopeless cases. You can be legally blind without being blind. How about being legally dead?
References New York State Department of Health: Guidelines for determining brain death, 2011. New York City Health and Hospitals Corporation Corporate Brain Death Policy (email me at James.Zisfein@nychhc.org for a copy) Wijdicks E.F.M, et al. Evidence-based guideline update: Determining brain death in adults: Report of the quality standards subcommittee of the American Academy of Neurology. Neurology 2010; 74:1911-1918. Lustbader D, et al. Second brain death examination may negatively affect organ donation. Neurology 2011; 76:1-6.