[Clinical diagnostic of brain death and transcranial Doppler, looking for middle cerebral arteries and intracranial vertebral arteries. Agreement with scintigraphic techniques].

INTRODUCTION

The Real Ordinance 2070/1999 meant an important modification in the legislation, when including transcranial Doppler (TCD) in explorations to confirm the clinical diagnosis of brain death (BD). Habitually for their employment in the diagnosis of BD, we look for blood flow signal from the middle cerebral arteries (MCA) and the basilar artery (BA).

OBJECTIVES

To check the effectiveness of the TCD like test of BD, looking for both middle cerebral arteries (MCA) and both intracranial vertebral arteries (VA), instead of the BA, and taking as Gold Standard cerebral scintigraphic techniques.

PATIENTS AND METHODS

. We present 25 patients diagnosed clinically with BD; on these TCD was carried out to confirm BD. Later on we proceeded to carry out cerebral scintigraphic techniques in all these cases. As statistical tool the test of c2 is used with confidence interval of 95%.

RESULTS

In 24 of the 25 cases, the TCD was effective in confirming the diagnosis of BD. In the remaining patient, a false positive result was obtained, since the TCD didn't reveal flow in the infratentorial compartment, as contrary to the cerebral scintigraphic techniques which showed the presence of residual flow at this level; this residual flow disappeared in 36 hours. This patient was hemodynamically unstable during TCD exploration.

CONCLUSIONS

In our results the TCD obtains a reliability of 100% when confirming the absence of blood flow in the supratentorial compartment; nevertheless the false positive result obtained at the infratentorial level, warns us to be cautious in accepting the flow from the VA as a test of absence of flow at the infratentorial compartment, especially in those patients with hemodynamic instability.