Reliability in diagnosis of brain death

Brain death in children

In 1981, the Report of the Medical Consultants on the Diagnosis of Death established guidelines for the diagnosis of brain death and, in 1995, the American Academy of Neurology published practice parameters to standardize determination of brain death. In 1987, the American Academy of Pediatrics established guidelines for determining brain death in children. Despite the establishment of these guidelines, the declaration of "death" based on the cessation of brain function remains complex and controversial. In this review are discussed the current guiding principles and the controversies in the diagnosis of brain death in children.

Transcranial Doppler during suspected brain death in children: Potential limitation in patients with cardiac "shunt"

OBJECTIVES: We report a potential limitation of transcranial Doppler for assessing cerebral circulation during suspected brain death in children. DESIGN: Review of two case series identified during our clinical practice. PATIENTS: Eight children with suspected brain death and seven with intact-brain and cardiovascular anomalies. MEASUREMENTS AND MAIN RESULTS: Brain-death criteria included lack of cerebral-brainstem reactivity, electrocortical silence and absent blood flow by brain scintigraphy ((99m)Tc-hexamethylpropylenamine oxime). Five intracranial Doppler patterns were found in eight cases of suspected brain death: A) orthograde continuous flow; B) reduced systolic flow velocity with absence of diastolic flow; C) reduced systolic flow velocity with retrograde diastolic flow, sometimes with antegrade late diastolic flow; D) systolic spikes of very low flow velocity; and E) absence of Doppler signals. Only patterns "C," "D," and "E" were associated with the absence of supra- and infratentorial brain perfusion. The most common Doppler alterations in patients with intact-brain and cardiovascular anomalies were the absence of diastolic flow (pattern "B") or the presence of retrograde flow during diastole (pattern "C"). CONCLUSION: Transcranial Doppler monitoring of pediatric patients may have value in identifying patients who have severe cerebral compromise, who may progress to brain death. However, key Doppler alterations, such as absent or retrograde flow during diastole, are not uniquely associated with the diagnosis of brain death, particularly in the setting of congential heart disease. The use of conventional methodology for the diagnosis of brain death in infants and children remains the "gold standard."

Consensus opinion on diagnosis of cerebral circulatory arrest using Doppler-sonography: Task Force Group on cerebral death of the Neurosonology Research Group of the World Federation of Neurology

BACKGROUND AND PURPOSE

Oscillating flow or systolic spikes are typical Doppler-sonographic flow signals found in the presence of cerebral circulatory arrest, which if irreversible, results in brain death. The Neurosonology Research Group (NSRG) of the World Federation of Neurology (WFN) created a Task Force Group in order to evaluate the role of Doppler-sonography as a confirmatory test for determining brain death.

METHODS

The available evidence from the literature has been reviewed and discussed by a group of experts, the members of the Task Force Group on cerebral death of the NSRG.

RESULTS AND CONCLUSIONS

Extra- and intracranial Doppler-sonography is a useful confirmatory test to establish irreversibility of cerebral circulatory arrest as optional part of a brain death protocol. Doppler-sonography is of special value when the therapeutic use of sedative drugs renders electroencephalography unreliable. Doppler-sonographic criteria are defined and guidelines for the use of Doppler-sonography in this setting are presented.