van der Naalt J, Baker A J
Critical Care Unit, St Michael's Hospital, Toronto, Canada.
Stroke. 1996 Jan;27(1):140-2. doi: 10.1161/01.str.27.1.140.
Confirmation of clinical brain death with transcranial Doppler (TCD) has been described. With the introduction of mechanical assist devices, it is important to know how these devices influence TCD measurements.
A patient who fulfilled the clinical criteria for brain death after cardiac arrest is described. An intra-aortic balloon pump (IABP) was necessary to maintain hemodynamic stability. A TCD examination was performed as an adjunct to the clinical diagnosis of brain death. A pattern of reversal of blood velocity typical of brain death was observed. With the IABP functioning, an increase of mean forward flow velocity without appreciable increase in the net flow velocities was seen. The results of the TCD measurements with the IABP functioning are not in concordance with values reported in the literature that confirm the clinical diagnosis of brain death.
Application of TCD in a patient with an IABP could lead to false interpretation of results if the TCD mean velocities are not registered with the IABP on standby or if the net flow velocities are not calculated.
