GUIDELINES FOR DECLARATION OF DEATH BY BRAIN CRITERIA 1*
05 November 2004
Brain Death2* is a clinical diagnosis which can be made when there is complete and irreversible cessation of all brain function. Since it is now technically possible to sustain cardiac, circulatory respiratory and other organ function after the brain has ceased to be alive, a diagnosis of brain death can be made before the heart beat stops.
The diagnosis of brain death is based primarily on clinical criteria. A confirmatory laboratory test may be done to supplement the clinical diagnosis.
An individual with irreversible cessation of all brain function, including the brain stem, is dead.
By Federal Law, you must notify the New England Organ Bank, 1-800-446-6362, as soon as you believe brain death may occur. Do not wait until after you have made the declaration.
The presence of sedative drugs, hypothermia, shock, or other potentially reversible conditions that may depress brain function must be excluded for these clinical criteria to be valid:
The clinical examination should be done by a neurologist, neurosurgeon, or critical care attending who is familiar with the neurological examination and with these criteria:
The patient should be deeply comatose with no movements, no withdrawal, seizures, or posturing (decerebrate or decorticate), spontaneously or to noxious stimulation. There may be spinal cord reflexes.
Apnea may be demonstrated by the absence of spontaneous respiration in the presence of an adequate carbon dioxide (CO2) drive.
The apnea test is a clinical bedside test to determine the response of the medullary brain stem respiratory center to a CO2 stimulus. In the absence of significant pulmonary disease or neuromuscular paralysis, a lack of respiratory effort to hypercarbia implies destruction of the most caudal part of the brain stem.
The test is begun by pre-oxygenation with 100% oxygen via the ventilator for about 5 minutes. The ventilator is withdrawn and the trachea is cannulated with an oxygen catheter. A passive flow of 100% oxygen at 4 1/min allows the PCO2 to rise without hypoxia. A baseline arterial blood gas (ABG) is drawn to ensure that the PCO2 is normalized. Observe the patient's undraped chest and abdomen for respiratory effort. After 5 and l0 minutes an ABG is drawn and the patient returned to the ventilator. A pulse oximeter should be used.
If in the presence of a negative drug screen and in the absence of metabolic intoxication, evidence of a paralyzing disease (e.g. Guillan-Barre, Myesthenia Gravis), or of neuromuscular blockade, there is no respiratory effort after an arterial PCO2 of more than 60 mm Hg has been achieved, the patient is apneic. Usually an ABG is drawn at baseline, 5 and 10 minutes.
The apnea test is done near the end of the period of observation. Patients whose PO2 cannot be maintained at normal levels may be excluded from a formal, apnea test.
It is recognized that on some occasions departure from the above procedures may be necessary. The reasons for such departure, if taken, should be documented in the patient's record.
Head is at 30°
horizontal semicircular canal into vertical and position of maximal sensitivity
auditory canal stimulated for 30 sec at temp of 30°
above & below body temp) with 5 minutes between each irrigation
stimulation: ipsilateral tonic deviation with nystagmus away
stimulation: nystagmus towards side of stimulation.
tonic downward deviation with nystagmus upward
Bilateral warm stimulation: tonic upward deviation with nystagmus downward.
The presence of deep tendon or other spinal reflexes does not preclude the diagnosis of brain death.
The clinical examination may be repeated after 12-24 hours. When there is a structural brain damage and the diagnosis is known with certainty, a shorter period of observation is adequate if central nervous system depressant drugs, metabolic and anoxic causes have been excluded.
A confimatory test supplements but is not a requirement for the clinical diagnosis of brain death. Absence of cerebral blood flow demonstrated by radionuclide flow study or angiogram or electrocerebral silence on electroencephalography is considered confirmatory.
EEG recording is done for at least 30 minutes, with electrode distances of at least 10 cm and impedances between 100 and 10, 000 ohms. It is considered isoelectric if there is no cerebral activity greater than 2 micro volts in amplitude.
Either confirmatory test should be repeated if the result is equivocal.
In situations where there is an inability to do an adequate clinical examination, such as high levels of barbiturates, or in cases of massive facial trauma, absence of brain circulation (to cerebral hemispheres and brain stem) on four vessel cerebral angiography is considered definitive of brain death. A radionuclear flow study is not sensitive for brain stem circulation and, therefore, a single scan is not adequate.
1* Note: These guidelines have been developed to assist the physician in the determination of brain death in adults and in children 5 years and older. For children younger than 5 years of age, consultation with a pediatric neurologist or neurosurgeon should be obtained.
2* Guidelines for determination of death: Report of the medical consultants on the diagnosis of death to the President's Commission for the study of ethical problems in medicine and biomedical behavioral research. JAMA. 246:2184-2186. 1981