A prospective observational study on intracranial pressure management: A comparison of three ultrasound techniques

Objective: This prospective observational study aimed to assess the effectiveness of B-mode ultrasound, colorcoded Doppler, and shear-wave elastography in predicting intracranial pressure (ICP) and their capability to evaluate the efficacy of ICP lowering therapy. Materials and methods: Forty-eight neuro-critical care patients were enrolled and categorized into 2 groups based on ICP measurements obtained through external ventricular drainage: the intracranial hypertension (IH) and normal ICP groups. The optic nerve (ON) sheath diameter (ONSD), end diastolic velocity, peak systolic velocity, resistance index of the central retinal artery (CRA), and Young's modulus (YM) of the ON were recorded after external ventricular drainage placement and following ICP lowering treatment in the IH group. Results: The median values of ONSD (5.35 mm [IQR 5.03, 5.80 mm] vs. 4.38 mm [IQR 4.25, 4.60 mm]) and YM of the ON (23.69 kPa [IQR 18.83, 30.90 kPa] vs. 10.48 kPa [IQR 9.84, 12.41 kPa]) were remarkably higher in the IH group than in the normal ICP group (both P < 0.001). However, no obvious differences were observed in end diastolic velocity, peak systolic velocity, or resistance index of the CRA between the two groups (all P > 0.05). Additionally, analysis of the differences in ultrasound parameters before and after treatment revealed that Delta YM of the ON exhibited higher sensitivity and specificity in detecting successful treatment of IH compared to Delta ONSD. Conclusion: Delta YM of the ON may serve as a more valuable parameter for reflecting changes in ICP and predicting the efficacy of treatment. In contrast, the color-coded Doppler indices of the CRA had limited values in evaluating ICP.