Variability of brain death determination guidelines in leading US neurologic institutions
Kao-ChangLin, Neurology, Chi Mei Medical Center, 901, Jong Hwa Rd, Yung Kung City, Tainan Hsien, Taiwan[email protected]
Jinn-Rung Kuo, Neurosurgery, Chi Mei Medical Center
Submitted February 14, 2008
Since the diagnosis of brain death (BD) can be made based on neurological examination, CO2 apnea tests, ancillary studies as electroencephalography (EEG), arteriography, or radionuclide scan [6], the use of TCD to determine BD seemed uncommon in the US. [1] The timing of confirmed “true” circulatory death is an ethical issue for all countries and cultures.
From the 2004 AAN reports, transcranial Doppler (TCD) used to confirm BD was 91-100% in sensitivity and 97-100% in specificity. [4] This simple technique is useful as a supplementary apparatus to verify physiological death once clinically diagnosed BD was made. However, the criticism was partly made because of the timing in performance, the flow spectrum, and the controversy in interpretation. If a standard protocol is set, neurologists and neurosurgeons could perform neurological assessments, TCD and apnea tests and additional procedures could be avoided. In some countries, TCD is allowed to confirm BD by law. [5]
We performed a four-year survey of 101 clinically-diagnosed BD by TCD monitoring. [7] The sensitivity and specificity was high (77% vs 100%) in middle cerebral artery and basilar artery. The positive predictive value was 100% on both. Specific flow patterns (both reverberating and small systolic flow) were characteristic of cerebral circulatory arrest. Although the lag period of these flow patterns were time-dependent (6~36 hrs), TCD should remain a first-line tool in the diagnosis of BD. [7]
References
6. Paolin A, Manuali A, Di Paola F, et al. Reliability in diagnosis of brain death. Intensive Care Med 1995; 21: 657-662.
7. Kuo JR, Chen CF, Chio CC, et al. Time-Dependent Validity in the Diagnosis of Brain Death Using Transcranial Doppler Sonography. JNNP 2006; 77: 646-649.
Disclosure: The authors report no conflicts of interest.
Since the diagnosis of brain death (BD) can be made based on neurological examination, CO2 apnea tests, ancillary studies as electroencephalography (EEG), arteriography, or radionuclide scan [6], the use of TCD to determine BD seemed uncommon in the US. [1] The timing of confirmed “true” circulatory death is an ethical issue for all countries and cultures.
From the 2004 AAN reports, transcranial Doppler (TCD) used to confirm BD was 91-100% in sensitivity and 97-100% in specificity. [4] This simple technique is useful as a supplementary apparatus to verify physiological death once clinically diagnosed BD was made. However, the criticism was partly made because of the timing in performance, the flow spectrum, and the controversy in interpretation. If a standard protocol is set, neurologists and neurosurgeons could perform neurological assessments, TCD and apnea tests and additional procedures could be avoided. In some countries, TCD is allowed to confirm BD by law. [5]
We performed a four-year survey of 101 clinically-diagnosed BD by TCD monitoring. [7] The sensitivity and specificity was high (77% vs 100%) in middle cerebral artery and basilar artery. The positive predictive value was 100% on both. Specific flow patterns (both reverberating and small systolic flow) were characteristic of cerebral circulatory arrest. Although the lag period of these flow patterns were time-dependent (6~36 hrs), TCD should remain a first-line tool in the diagnosis of BD. [7]
References
6. Paolin A, Manuali A, Di Paola F, et al. Reliability in diagnosis of brain death. Intensive Care Med 1995; 21: 657-662.
7. Kuo JR, Chen CF, Chio CC, et al. Time-Dependent Validity in the Diagnosis of Brain Death Using Transcranial Doppler Sonography. JNNP 2006; 77: 646-649.
Disclosure: The authors report no conflicts of interest.