Application of transcranial Doppler ultrasonography for the diagnosis of brain death

Objective:To determine the clinical validity of transcranial Doppler ultras onographic (TCD) signs of total cerebral circulatory arrest for confirmatio n of brain death and to define the test protocol. Design: Study of a diagnostic test. Setting: General and neurosurgery intensive care units. Patients: 137 patie nts in a coma (Glasgow Coma Score 3-5), caused by various pathological cond itions, observed from January 1992 to July 1998. 84 patients met the clinic al criteria of brain death; 43 patients out of 137 received sedative drug t herapy and 31 of these developed brain death. Results: Total cerebral circulatory arrest was demonstrated by TCD in 81 pa tients. All of them proved to be brain dead according to subsequent clinica l examination In 29 of 31 patients who had received sedative drug therapy T CD examination showed total cerebral circulatory arrest 12-48 h before the formal confirmation of the diagnosis. In 1 out of 84 clinically brain dead patients a false negative result was obtained. In 2 of 84 cases, no clear s ignals from intracranial vessels were obtainable. Fifty-three patients who did not meet the clinical criteria for brain death showed no TCD signs of t otal cerebral circulatory arrest. The specificity of the TCD test for confi rmation of brain death was 100 % and the sensitivity 96.5 %. Conclusions: In agreement with previously published data, we conclude that TCD ultrasonography is a highly specific and sensitive confirmatory test an d should be included as an additional test in the protocol for the assessme nt of brain death.