Pulsed ICA Doppler blood flow as a step in brain death diagnosis
© Current Science Ltd 1997
Published: 1 March 1997
Confirmation of brain death diagnosis, in addition to clinical examination, requires demonstration absent of cerebral blood flow with conventional cerebral angiography or magnetic resonance angiography. Transcranial Doppler is an alternate method to conventional cerebral angiography that is not invasive and does not require transport of the patient to the radiology department.
To evaluate the role of ICA Doppler as a step tool in brain death diagnosis.
A multidisciplinary ICU in our University Hospital.
Patients and methods
Twenty-four patients (mean age 23 ± 3, 15 male, 9 female) with diffuse cerebral edema on CT and had conventional anti-edema therapy were included in the study. In all patients at the time of the study GSC:3, spontaneous respiration (apnea test) and brain stem reflexes (including pupillary, corneal, oculocephalic, vestibulocephalic reflexes, tracheal gag) atropine test were absent.
Bilateral pulsed ICA Doppler blood flow measurements were done with Duplex (ATL ULTRAMARK 9/USA) and recorded. Extracranial blood flow velocity patterns of internal carotid arteries were bilaterally detected through the skin by a directional, 5–10 Hz pulsed-wave Doppler ultrasound.
ICA blood flow cessation was determined by the observation of early and small systolic spikes or reversal of blood flow in diastole.
In I5 patients normal ICA blood flow, in three patients early small systolic spikes and in six patients reversal of blood flow in diastole was observed.
In diagnosis of brain death our experience confirms that extracranial ICA Doppler in bedside is a clinically useful technique to separate the patients for further investigation (carotid angiography or magnetic resonance angiography). For 15 (63.5%) patients we could decide that there is no need for this invasive confirmatory technique. If transcranial Doppler is not available this non-invasive and most routinely available ICA Doppler method can be a good step for diagnosis of cerebral blood flow cessation in clinical brain death.