Transcranial pulsed Doppler ultrasound findings in brain stem death.

Continuous recording of middle cerebral artery blood velocity in clinical neurosurgery

“…The value of short term blood velocity recording in the prediction of brain tamponade and brain death has been shown in several studies 4,5,8,20,28,29 All four patients with severely impaired CO2 reactivity and three other critically ill patients showed corresponding changes in MCA blood velocity and CPP throughout the observed CPP range (up to 120 mm Hg). This pressure-passive velocity pattern suggests that these patients had an abolished blood velocity autoregulation.…”

Utility of transcranial doppler ultrasonography for confirmatory diagnosis of brain death: two sides of the coin

“…Transcranial Doppler ultrasonography (TCD) fulfils these criteria and has been demonstrated to be highly sensitive in documenting the arrest of cerebral circulation in brain-dead patients in many studies (7)(8)(9)(10)(11). Waveform abnormalities documented by TCD occur when intracranial pressure increases above the mean arterial pressure and are indicative of arrest or near arrest of cerebral circulation (8,12,13).…”

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

“…Nevertheless, 12 falsepositives have been reported to date [13][14][15][16][17][18][19][20][21][22][23][24]. Specifically, Kirkham et al [18] and Newell et al [13] reported a preserved weak spontaneous respiration for a short period of time (*1 h) in patients with TCD evidence of CCA. In neither of those studies, the cases were regarded as falsepositives by those authors, because the signs of circulatory arrest proved to be irreversible, and the patients soon became apnoeic.…”