OBJECTIVETo detect the influence of mannitol on cerebral blood flow of post-resuscitation children by transcranial Doppler (TCD).

METHODSThe blood flow changes of left side middle cerebral artery (MCA) and extracranial internal carotid artery (EICA) were monitored by TCD in 21 post-resuscitation children. TCD waveforms, peak velocity (Vp), diastolic velocity (Vd), mean velocity (Vm) and pulsitility index (PI) of MCA and EICA were monitored daily and 30 minutes before and after the first dose of mannitol. Glasgow scores were estimated in the meantime. The patients were divided into 2 groups according to the patterns of diastolic flow. Patients in group I showed no diastolic flow or retrograde diastolic flow (n = 9), and patients in group II had positive diastolic flow (n = 12).

RESULTSVp, Vd, Vm, PI of MCA and EICA in group I patients had no significant change after the administration of mannitol and the Glasgow scores were much lower than that of group II patients (P < 0.05). TCD waveforms showed no improvement in group I patients and their outcomes were poor. Vd, Vm and Vp of MCA and Vd of EICA in group II patients increased, PI of MCA decreased (P < 0.05), while Vp, Vm, PI of EICA had no significant change. TCD waveforms recovered within one week. All the patients in this group survived.

CONCLUSIONSThe results suggested that mannitol could improve cerebral perfusion in patients with mild brain damage. These patients usually had increased diastolic blood flow in the early stage. Lack of or retrograde diastolic flow of TCD waveforms might be associated with severe brain damage with poor outcome. Mannitol had no effect on improving cerebral blood flow in these patients.