The effect of ICP monitoring in severe traumatic brain injury: a propensity score–weighted and adjusted regression approach

OBJECTIVE The use of intracranial pressure (ICP) monitoring has been postulated to be beneficial in patients with severe traumatic brain injury (TBI), although studies investigating this hypothesis have reported conflicting results. The objective of this study was to evaluate the effect of inserting an ICP monitor on survival in patients with severe TBI. METHODS The Oslo University Hospital trauma registry was searched for the records of all patients admitted between January 1, 2002, and December 31, 2013, who fulfilled the Brain Trauma Foundation criteria for intracranial hypertension and who survived at least 24 hours after admission. The impact of ICP monitoring was investigated using both a logistic regression model and a multiple imputed, propensity score–weighted logistic regression analysis. RESULTS The study involved 1327 patients, in which 757 patients had an ICP monitor implanted. The use of ICP monitors significantly increased in the study period (p < 0.01). The 30-day overall mortality was 24.3% (322 patients), divided into 35.1% (200 patients, 95% confidence interval [CI] 31.3%–39.1%) in the group without an ICP monitor and 16.1% (122 patients, 95% CI 13.6%–18.9%) in the group with an ICP monitor. The impact of ICP monitors on 30-day mortality was found to be beneficial both in the complete case analysis logistic regression model (odds ratio [OR] 0.23, 95% CI 0.16–0.33) and in the adjusted, aggregated, propensity score–weighted imputed data sets (OR 0.22, 95% CI 0.15–0.35; both p < 0.001). The sensitivity analysis indicated that the findings are robust to unmeasured confounders. CONCLUSIONS The authors found that the use of an ICP monitor is significantly associated with improved survival in patients with severe head injury.