To-and-Fro Movement and External Escape of Carotid Arterial Blood in Brain Death Cases. A Doppler Ultrasonic Study

Abstract

Abstract:To • In brain death cases who showed nonfilling phenomena in the internal carotid angiograms, the blood flow velocity patterns of the common carotid arteries were characterized by involvement of a single systolic peak and a marked reverse flow component which had never been observed in healthy subjects.The individuality of each blood flow velocity pattern in the common, internal and external carotid arteries was made clear by placing the transducer in contact with the respective artery in a certain case. The Doppler signal from the internal carotid artery involving a signal from a reverse flow was slightly detectable, even if the blood pressure was elevated by norepinephrine infusion and the external carotid artery was temporarily compressed. The blood flow velocity pattern of the external carotid artery was similar to the pattern of the common carotid artery. The peculiar flow pattern indicates that a brain death case has a to-and-fro movement in the internal carotid blood flow and an external carotid escape of common carotid arterial blood.

The case against confirmatory tests for determining brain death in adults

“…During the years since that report, additional confirmatory tests have been introduced in the medical literature 11,[16][17][18][19][20][21][22][23] (table 1), and a picture has emerged that reliable tests are available. The tests can be divided into those that evaluate electrical function and those that assess blood flow.…”

Transcranial Doppler Ultrasonography in the Assessment of Cerebral Circulation Arrest: Improving Sensitivity by Trancervical and Transorbital Carotid Insonation and Serial Examinations

“…It has been demonstrated that the insonation of the ICA at the level of the siphon and at the extracranial level, through transorbital and cervical insonation, may show a sonographic pattern of circulatory arrest [39,40]. This gives evidence for the absence of flow in the whole anterior cerebral circulation, even in case of lack of temporal windows.…”

Brain Death Guidelines Explained

“…76 Transcranial Doppler is a validated confirmatory test, with sensitivity varying from 91% to 99% and a specificity of 100%. [77][78][79][80][81][82][83][84][85][86][87][88] A portable Doppler device is used with insonating of both middle cerebral arteries through the temporal bone above the zygomatic arch. The posterior circulation should be insonated, but the distal basilar artery cannot be reliably seen.…”