INTRODUCTION: It is unclear if intracranial pressure monitoring (ICPM) after open cranial procedures (craniotomy or craniectomy) (OC) for traumatic brain injury is associated with mortality. We hypothesized that ICPM placed early after OC was associated with lower mortality compared to no ICPM or delayed ICPM placement. METHODS: Using 2020-2021 data from the American College of Surgeons Trauma Quality Improvement Program, patients ≥16 y from level 1 and 2 trauma centers who underwent OC were divided into two groups: ICPM placed within 72 h of OC (early) and no ICPM or ICPM placed after 72 h (none/delayed). Outcome was in-hospital mortality. Logistic regression was used to elucidate predictors of mortality. RESULTS: A total of 19,830 patients (early ICPM, 29%) were included. Early patients were more likely to be from level 1 centers (63% versus 60%, P = 0.004), younger (median age 47 versus 60, P <
0.0001), to have a lower Glasgow Coma Score (median, 6 versus 14, P <
0.0001), higher injury severity score (median, 26 versus 26, P <
0.0001), an unreactive pupil (33% versus 18%, P <
0.0001), midline shift >
5 mm (69% versus 60%, P <
0.0001), received ≥2 units of blood/first 4 h (14% versus 6%, P <
0.0001) and higher mortality (31% versus 19%, P <
0.0001) compared to none/delayed patients. Controlled for significant variables, early ICPM was associated with increased mortality (odds ratio 1.35, 95% confidence interval 1.24-1.47). Analysis of subjects with isolated brain injury found a similar association (odds ratio 1.32, 95% C1 1.15-1.52). CONCLUSIONS: ICPM placed within 72 h of OC was associated with increased mortality. Indications for ICPM after OC should be investigated further in multicenter prospective studies.