Analysis of correlation between intracranial pressure and outcome in traumatic brain injury patients

Abstract

Objective To reveal the relationship of outcome to intracranial pressure in traumatic brain injury patients. Methods Clinical data of 50 patients with traumatic brain injury (TBI) admitted to Neurosurgical Intensive Care Unit, Renji Hospital, Shanghai Jiaotong University School of Medicine from November 2016 to October 2017 were retrospectively analyzed. All of them received intracranial pressure (ICP) and arterial blood pressure (ABP) monitoring and the ICP-derived parameters were monitored by Neumatic DCR system. The 50 TBI patients were divided into the group of poor prognosis [Glasgow Outcome Scale (GOS) Ⅰ-Ⅱ, n=20] and the group of good prognosis (GOS Ⅲ-Ⅴ, n=30) according to GOS at discharge. We analyzed and compared various ICP-derived parameters between those two groups. The receiver operating characteristic (ROC) curve was used to assess the outcome predictive power of the parameters. Results (1) Compared with those in group of good prognosis, patients in poor prognosis group tended to have higher ICP (26.2±13.4 mmHg vs. 14.0±5.6 mmHg), higher pressure reactivity index (PRx, 0.48±0.21 vs. 0.12±0.08) and closer ICP-ABP wave amplitude correlation (IAAC, 0.14 vs. 0.01), while their cerebral perfusion pressure (CPP) was lower than control (48.9±19.9 mmHg vs. 81.1±6.9 mmHg, all P 0.05). It was suggested by multiple logistic regression that ICP (OR=2.187, 95%CI: 1.079-4.431, P=0.031) and PRx (OR=21.608, 95%CI: 3.012-155.014, P=0.002)were two risk factors associated with poor outcome in TBI patients. (2) ICP dose in poor prognosis group under either threshold of 22 mmHg (DICP22) and 20 mmHg (DICP20) was higher than that in good prognosis group (P<0.05). The area under curve (AUC) of ROC was 0.70 for DICP20 and 0.71 for DICP22. PRx dose in poor prognosis group under either threshold of 0.25 (DPRx0.25) and 0.05 (DPRx0.05) was higher than that in good prognosis group (P<0.05). The area under curve (AUC) of ROC was 0.97 for DPRx0.25 and 0.96 for DPRx0.05. Conclusions ICP and PRx are two risk factors associated with poor outcome in TBI patients. Both ICP and PRx doses could help predict the outcome of death or vegetative state in TBI patients and PRx dose seems to have a relatively higher accuracy. Key words: Craniocerebral trauma; Prognosis; Intracranial pressure derived parameter