Transcranial color-code sonography non-invasive assessment of intracranial pressure after decompressive craniectomy in patients with acute severe traumatic brain injury

Objective To evaluate the accuracy of transcranial color-code sonography (TCCS) in non-invasive assessment of intracranial pressure(ICP). TCCS was used to monitor the cerebral hemodynamic parameters of patients with acute severe traumatic brain injury after decompressive craniectomy and make estimation of the non-invasive intracranial pressure(ICPtccs). Methods A total of 91 patients with acute severe traumatic brain injury involved in this retrospective study were divided into the ICP normal group(≤22 mmHg) and the ICP increased group (>22 mmHg). The correlation and consistency of middle cerebral artery blood flow parameters and ICPtccs with invasive intracranial pressure (iICP) were analyzed.According to Glasgow score (GCS), Patients(GCS 3-8) were divided into acute extremely severe traumatic brain injury(GCS 3-5) and acute severe traumatic brain injury(GCS 6-8). A comparison was made of ROC (ICPtccs) curve and the area under the curve(AUC) between the two groups were cornpared. Results ①No statistical differences were found in cerebral hemodynamic parameters between the side with and without decompressive craniectomy in patients with acute severe traumatic brain injury(all P>0.05). ②Monitored resistive index (RI), pulsatility index (PI) and ICPtccs between the normal ICP group and the increased ICP group showed statistically significant differences (all P 0.05). The correlations between RI, PI with iICP were low (r=0.247, 0.221; all P<0.05), while there was a moderate correlation between ICPtccs and iICP(r=0.417, P<0.001). ③Bland-Altman plot showed an overestimation of 2.3 mmHg (95% CI 0.00-4.59 mmHg) for ICPtccs compared to iICP. ④The AUC of Glasgow score (GCS 3-5 and GCS 6-8) in the two groups were 0.759, 0.781 (all P<0.05). All the cut-off points of ICPtccs were 19 mmHg, with a sensitivity of 83.33%, 81.82% and a specificity of 64.86%, 75.68%, respectively. Pairwise comparison of two AUCs showed no statistical difference (P=0.476). ICPtccs presented the same ability to estimate ICP in patients with acute severe and extremely severe traumatic brain injury. TCCS could accurately assess the elevation of ICP in 72.52% patients with acute severe traumatic brain injury. Conclusions TCCS can be used as a non-invasive screening tool to assess whether ICP of patients with acute severe traumatic brain injury is elevated and to semi-quantitatively estimate ICP, showing useful clinical value.