Low-dose mannitol (0.3 g kg−1) improves the pulsatility index and minimum diastolic blood flow velocity in traumatic brain injury

Abstract

Objective: The aim of the study was to investigate the effects of using low-dose mannitol (0.3 g kg−1) on the pulsatility index (PI) and minimum diastolic blood flow velocity (FV-min) of the middle cerebral artery in a traumatic brain injury (TBI).Methods: Low-dose mannitol (0.3 g kg−1) was administered to a group of 20 patients with a TBI. Transcranial Doppler (TCD) ultrasonography was used to monitor the PI and FV-min. The study included patients with a diffuse traumatic brain injury and Glasgow coma score < 8. The initial TCD ultrasonography values were pathological (PI > 1.4 and FV-min < 20 cm s−1). TCD ultrasonography examinations were carried out before mannitol administration, immediately after administration and 1, 2 and 3 hours after the administration of mannitol.Results: A one-way analysis of variance revealed significant changes in the PI (F = 8.392; p < 0.001) and FV-min (F = 8.291; p = 0.001) after the use of mannitol.Conclusions: Low-dose mannitol administration appears to be efficacious for improving the indicators of disturbed circulation in a TBI (FV-min increase, PI decrease). The maximum decrease in the PI was recorded 1 hour after the administration of mannitol and was 10.9% of the initial value. The maximum increase in the FV-min was recorded 1 hour after administration and was 29.7% of the initial value. These changes were significant ∼ 2 hours later.