Burden of Intracranial Hypertension and Patterns of Brain Injury on MRI: Secondary Analysis of the 2014-2017 "Approaches and Decisions for Acute Pediatric TBI" Study.

Abstract

Objectives: Elevated intracranial pressure (ICP) is a complication of severe traumatic brain injury (TBI) that carries a risk of secondary brain injury. This study investigated the association between ICP burden and brain injury patterns on MRI in children with severe TBI.

Design, setting, and patients: Secondary analysis of the Approaches and Decisions in Acute Pediatric TBI (ADAPT) study, which included children with severe TBI (Glasgow Coma Scale score < 9) who received a clinical MRI within 30 days of injury. We excluded patients who had ICP monitoring less than 24 hours, were missing ICP data for greater than 40% of monitoring time, or who underwent craniectomy.

Interventions: None.

Measurements and main results: ICP burden was defined as the trapezoidal area under the curve of hourly ICP greater than 20 mm Hg. ICP was standardized to total monitoring time, and patients were categorized to four levels of ICP burden. MRI was evaluated for number of diffuse axonal injury (DAI) microhemorrhages, intracerebral hemorrhage (ICH) volume, contusion volume, and number of regions with ischemia. Fisher exact or chi-square tests were used to test the independence between ICP burden and MRI injury amount. Of the 220 patients, 156 (71%) had DAI, 31 (14%) had ICH, 161 (73%) had contusions, and 70 (32%) had ischemia on MRI. Most patients (180, 82%) experienced episodes of ICP greater than 20 mm Hg. Contusion volume (p = 0.02) and number of regions with ischemia (p = 0.007) were associated with ICP burden, but we failed to identify such an association for DAI or ICH. Severe (but not mild or moderate) ICP burden was associated with presence of ischemia (odds ratio, 4.64 [95% CI, 1.30-19.5]; p = 0.02).

Conclusions: Elevated ICP was prevalent in the ADAPT cohort. Ischemia and contusion were associated with the burden of ICP. Further research is needed to determine temporal relationships between elevated ICP and ischemia.