Transcranial Doppler for early identification of potential organ transplant donors

Background: Encouraging results in transplant medicine create a growing demand for organ transplant donors. Transcranial Doppler (TCD) has been used by several investigators to assess arrest of the cerebral circulation in brain dead patients. We report on TCD as a monitoring tool for early identification of potential organ transplant donors. Design: A prospective clinical study. Setting: Intensive care unit (ICU) of a 900-bed community hospital (primary and tertiary care center) in Vienna, Austria. Subjects and methods: All patients with acute intracranial lesions admitted to our intensive care unit underwent TCD examination at least once daily, In patients with Glasgow Coma Scores <7, TCD waveforms with high resistance profiles unchanged by therapeutic attempts to lower intracranial pressure indicated the need for repeated TCD up to four times a day. TCD waveform abnormality consisting of absent or reversed diastolic flow or small early systolic spikes in at least two intracranial arteries was considered to constitute intracranial circulatory arrest. Brain death was confirmed by clinical criteria, an isoelectric electroencephalography (EEG) or non filling of the intracerebral arteries on arteriography. Results: From January 1994 to July 1996 we identified 11 comatose patients as potential organ transplant donors with typical TCD findings indicating intracranial circulatory arrest. Diagnosis was subarachnoid hemorrhage in 7 and intracerebral hemorrhage in 4 patients. Brain death diagnosis according to the criteria of Austrian law was initiated immediately after the TCD findings suggested intracranial circulatory arrest. Confirmation of brain death was obtained by clinical criteria and either EEG (6 patients) or cerebral angiography (5 patients). Conclusion: TCD examinations on a daily routine basis offer a noninvasive monitoring method for early assessment of intracranial circulatory arrest. TCD enables quick identification and further diagnosis of candidates for organ transplant donation.