JAMA Pediatrics Journal Club Slides: Intracranial Pressure Monitoring for Children With Severe Traumatic Brain Injury Bennett TD, DeWitt PE, Greene TH, et al. Functional outcome after intracranial pressure monitoring for children with severe traumatic brain injury. JAMA Pediatr. Published online August 28, 2017. doi:10.1001/jamapediatrics.2017.2127

Introduction Importance: Traumatic brain injury (TBI) causes approximately 2200 deaths and 35 000 hospitalizations in US children annually. Elevated intracranial pressure (ICP) often results from severe TBI and worsens patient outcome by causing additional brain injury. ICP monitoring is used to detect elevated ICP and to guide treatment of severe TBI. ICP monitoring is a mainstay of therapy for children with TBI, but its overall association with patient outcome is unclear. Objective: To test the hypothesis that ICP monitoring is associated with improved functional survival of children with severe TBI.

Methods Study Design, Setting, and Participants: Design: Propensity-weighted effectiveness analysis using 2 linked national databases. Clinical events including neurosurgical procedures were identified using validated computable phenotypes. Setting: 30 US children's hospitals from 2007 to 2012. Participants: 3084 children with severe TBI. Data Analysis Exposure: ICP monitor placement. Main outcome: A composite of hospital mortality, discharge to hospice, or survival with new tracheostomy and gastrostomy tubes. Propensity model developed using generalized boosted regression targeting optimal covariate balance (standardized mean difference [SMD]). No variable had an SMD >5% in the final propensity model. Outcome model weighted by propensity matching weights and adjusted for clustering by hospital.

Methods Limitations: No available data for measured ICP values, results from brain computed tomography studies, or progression of neurologic examination. Medical decision-making information not available. Sensitivity analyses suggest unmeasured differences between treatment groups.

Results A total of 3084 patients at 30 hospitals were included. The mean (SD) age of patients was 7.03 (5.44) years. 675 of 3084 patients (21.9%) were injured by known or suspected child abuse. Overall, 1002 of 3084 patients (32.5%) underwent ICP monitoring. ICP monitoring rates varied widely by hospital, from 6% to 50%. Those who underwent ICP monitoring were more likely to be injured in motor vehicle incidents; had poorer Injury Severity Scores, poorer Glasgow Coma Scale scores, and Glasgow Coma Scale motor scores; and were more likely to have subdural and intraventricular or subarachnoid hemorrhages. Substantial clinical equipoise appeared to be present for ICP monitoring because many children with propensities from approximately 0.1 to 0.6 either underwent or did not undergo ICP monitoring.

Results Density of Propensity Scores by Actual Receipt of Intracranial Pressure (ICP) Monitoring

Results Hospital mortality was 12.4% overall (n = 382), and 484 patients (15.7%) had the primary outcome of mortality, discharge to hospice, or poor functional survival. Both mortality (18.5% vs 9.5%) and the primary outcome (24.3% vs 11.6%) were higher among those who received ICP monitoring. No between-group differences were seen in rates of complications, such as prehospital or emergency department hypotension (SMD, 0.78%) or cardiac arrest (SMD, 1.72%). In the primary analysis, we found no statistically significant difference in functional survival between those who underwent ICP monitoring and those who did not. In prespecified secondary analyses (also performed using matching weights), ICP monitoring was not significantly associated with hospital mortality but was associated with a higher likelihood of mortality, discharge to hospice, and either tracheostomy or GT.

Results Association of Intracranial Pressure (ICP) Monitoring With Mortality or Poor Functional Survival

Results In the sensitivity analyses, children who underwent ICP monitoring had longer lengths of hospital stay and mechanical ventilation and more days of osmolar therapy, inotropes or pressors, and pentobarbital (all P < .001). Differences in pentobarbital use were not explained by use as an antiepileptic rather than an anesthetic because more children without ICP monitoring (37 of 121 [30.6%]) than with ICP monitoring (61 of 252 [24.2%]) had seizures (SMD = 14%). Children who underwent ICP monitoring were also more likely to undergo a craniotomy or craniectomy (SMD = 57%).

Comment In this large, multicenter, propensity-weighted analysis of children with severe TBI, we found no evidence of an association of ICP monitoring with functional survival. Mortality, a prespecified secondary outcome, also did not differ significantly between treatment groups. Children who underwent ICP monitoring had longer hospital stays and received more therapies directed at intracranial hypertension.

Comment This result is consistent with the results of a randomized trial of ICP monitoring in adults (Chesnut RM, Temkin N, Carney N, et al. N Engl J Med. 2012;367(26):2471-2481.), which found no difference in 6-month outcome between care directed by ICP monitoring vs imaging and clinical examination. No randomized trial of ICP monitoring has been conducted for children, to our knowledge. Our sensitivity analyses raise questions about between-group differences despite the seemingly excellent covariate balance we achieved. Because ICP monitoring is a widely but inconsistently used technology with incompletely demonstrated effectiveness, a large prospective cohort study or randomized trial is needed.

Conflict of Interest Disclosures Contact Information If you have questions, please contact the corresponding author: Tellen D. Bennett, MD, MS, Pediatric Critical Care, University of Colorado School of Medicine, 13199 E Montview Blvd, Ste 300, Campus Mail F443, Aurora, CO 80045 (tell.bennett@ucdenver.edu) Funding/Support This work was supported by grant K23HD074620 from the Eunice Kennedy Shriver National Institute for Child Health and Human Development (Dr Bennett) and Colorado Clinical and Translational Science Institute grant UL1 TR001082 from the National Center for Research Resources. Conflict of Interest Disclosures None reported.