Abstract
Background
As a noninvasive monitoring measure, transcranial Doppler ultrasound (TCD) has been widely used to monitor the secondary brain injury in patients with traumatic brain injury (TBI). There are different physiological theories on the noninvasive assessment of intracranial pressure by TCD parameters, including ONSD and PI, which may cause that the change of ONSD and PI is not always synchronous with that of ICP. Therefore, the objective of this study was to investigate the relationship between PI or ONSD and ICP at different levels or in different periods after the operation, and the ability of prediction intracranial hypertension with these parameters in patients with TBI.
Methods
The clinical data of 68 patients with TBI were retrospectively analyzed. The statistical correlation analysis was performed to investigate the relationship between the PI or ONSD and ICP one week after the operation. Besides, the area under the curve (AUC) of ONSD or PI alone or a combination of them was calculated to determine the ability of intracranial hypertension.
Results
1. There was a correlation between ONSD and ICP ≥ 20 mmHg (r = 0.665, p < 0.001), ICP < 20 mmHg (r = 0.358, p = 0.006). The correlation still remained at ONSD ≥ 5 mm (r = 0.644, p < 0.001), but no correlation at ONSD < 5 mm (p = 0.137). 2. There was a strong correlation between PI and ICP at ICP of 15–20 mmHg (r = 0.705, p < 0.001), and ICP ≥ 20 mmHg (r = 0.716, p < 0.001). Nevertheless, it revealed a weak correlation at PI < 1.2 (r = 0.271, p = 0.021), PI ≥ 1.2 (r = 0.350, p = 0.020). In different period after the operation, there was a moderate correlation between ICP and PI on days 3, 4, and 5 (r = 0.508, p < 0.001), a strong correlation on days 6 and 7 after the operation (r = 0.645, p < 0.001). 3. For prediction intracranial hypertension with PI ≥ 1.2 or ONSD ≥ 5 mm alone or a combination of ONSD ≥ 5 mm and PI ≥ 1.2, the AUC value was 0.729 (p < 0.001), 0.900 (p < 0.001), and 0.943 (p < 0.001), respectively.
Conclusion
The correlation between the parameters of TCD, including ONSD and PI, and invasive ICP vary at different levels of ICP and in different periods in patients with TBI post-operation. It could also allow for a more accurate prediction of elevated intracranial pressure with a combination of ONSD ≥ 5 mm and PI ≥ 1.2.
Transcranial Doppler Ultrasound Examination in Dogs with Suspected Intracranial Hypertension Caused by Neurologic Diseases
