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.

• Low-dose mannitol
• minimum diastolic blood flow velocity
• pulsatility index
• traumatic brain injury
• transcranial Doppler ultrasonography

Acknowledgements

The authors thank the staff of the intensive care unit at the University Hospital Split who assisted in carrying out this research.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.