Non⁃invasive evaluation of intracranial pressure by transcranial Doppler ultrasound in patients with traumatic brain injury

Abstract

Objective To investigate the non⁃invasive evaluation of intracranial pressure (ICP) by transcranial Doppler ultrasound (TCD) in patients with traumatic brain injury (TBI). Methods The clinical data of 68 patients with TBI were retrospectively analyzed. Pulsatility index (PI) and optic nerve sheath diameter (ONSD) were performed by TCD, simultaneous recording of ICP parameter one week after surgery. The relationship between ONSD, PI and ICP was analyzed by Pearson correlation analysis. The area under the curve (AUC) was used to evaluate the diagnostic sensitivity of ONSD and PI for prediction intracranial hypertension. Results One week after surgery,ICP was positively correlated with ONSD (r= 0.679, P=0.000). There was also a positive correlation between ONSD and ICP ≥ 20 mm Hg (r=0.665, P= 0.000) and ICP<20mmHg (r=0.358, P=0.006). The positive correlation remained between ONSD and ICP at ONSD ≥ 5mm (r=0.644, P=0.000). There was a positive correlation between ICP and PI (r= 0.458, P=0.000),so does the correlation at ICP 15-20 mm Hg (r=0.705, P=0.000) and ICP ≥ 20 mm Hg (r=0.716, P=0.000). The positive correlation still remained between ICP and PI<1.20 (r=0.282, P=0.029) and PI≥1.20 (r=0.350, P=0.021). For prediction intracranial hypertension, the AUC value was 0.900(95%CI:0.831 0.969, P=0.000)for ONSD ≥ 5 mm, with sensitivity 0.821 and specificity 0.931, and the critical value of ONSD was 5 mm; the AUC value was 0.729 (95%CI:0.623-0.834, P=0.000) for PI ≥ 1.20, with sensitivity 0.483 and specificity 0.860, and the critical value of PI was 1.20; while the AUC valuewas 0.943 (95%CI:0.866-1.000, P=0.000) for a combination of ONSD ≥ 5 mm and PI ≥ 1.20, with sensitivity 1.000 and specificity 0.857, respectively. Conclusions ONSD and PI could be the non⁃ invasive evaluation of ICP level, but the degree of correlation with ICP varies at different levels of ICP. It is necessary to understand the meaning of the parameters according to the pathophysiology of TBI and then guide the clinical treatment.

DOI：10.3969/j.issn.1672⁃6731.2020.07.006