Is There an Optimal Time Window of Placement of Intracranial Pressure (ICP) Monitor for Elderly Patients with Severe Traumatic Brain Injury? An 11-Year Institutional Cohort Study with Restricted Cubic Spline Analysis

Severe Traumatic brain injury (sTBI) is a prominent contributor to both morbidity and mortality in the elderly population. The monitoring of intracranial pressure (ICP) is crucial in the management of sTBI patients. Nevertheless, the appropriate timing for the placement of ICP monitor in elderly sTBI patients remains uncertain. In order to determine the optimal timing for the placement of ICP monitor in elderly sTBI patients, in this retrospective cohort study, we collected data from elderly patients (> 65 years) who suffered sTBI and received ICP monitors at Tangdu Hospital, The Fourth Military Medical University, between January 2011 and December 2021. To examine the relationship between the time of ICP monitor placement and in-hospital mortality, we conducted a multivariate-adjusted restricted cubic spline (RCS) analysis. Additionally, logistic regression analysis was applied to further analyze the influencing factors contributing to early or late ICP monitor placements. A total of 283 eligible elderly TBI patients were included in the current analysis. The in-hospital mortality rate was 73 out of 283 (26%). The RCS analysis demonstrated an inverted U-shaped curve in the relationship between the timing of ICP monitor placement and in-hospital mortality. For the elderly sTBI patient cohort, 6 h was identified as the crucial moment for the treatment strategy. In addition, the protective time window for ICP placement was less than 4.92 h for GCS 3-5 group, and less than8.26 hours for GCS 6-8 group. However, the clinical benefit of ICP placement decreased gradually over time. The relationship between ICP placement and in-hospital mortality was non-linear, exhibiting an inverted U-shaped curve in elderly patients with sTBI. For elderly patients with sTBI, early (≤ 6 h) ICP placement was associated with reduced in-hospital mortality. The clinical benefit of ICP placement decreased beyond the optimal time window.