J Trauma Acute Care Surg. 2018 Aug;85(2):380-386

# A clinical prediction model for raised intracranial pressure in patients with traumatic brain injury.

Pace J, Parry N, Vogt K, Hilsden R, Leeper R, Markova Z, Priestap F, Younan J, Ball I.

BACKGROUND: Intracranial hypertension is believed to contribute to secondary brain insult in traumatically brain injured patients. Currently, the diagnosis of intracranial hypertension requires intracranial monitoring or advanced imaging. Unfortunately, prehospital transport times can be prolonged, delaying time to the initial radiographic assessment. The aim of this study was to identify clinical variables associated with raised intracranial pressure (ICP) prior to the completion of neuroimaging.

METHODS: We performed a retrospective cohort study of head injured patients over a 3-year period. Patients were labeled as having increased ICP if they had a single reading of ICP greater than 20 mm Hg within 1 hour of ICP monitor insertion or computed tomography findings suggestive of raised ICP. Patient and clinical characteristics were analyzed using stepwise multivariable logistic regression with ICP as the dependent variable.

RESULTS: Of 701 head injured patients identified, 580 patients met inclusion criteria. Mean age was 48.65 ± 21 years, 73.3% were male. The mean Injury Severity Score was 22.71 ± 12.38, and the mean Abbreviated Injury Scale for body region head was 3.34 ± 1.06. Overall mortality was 14.7%. Only 46 (7.9%) patients had an ICP monitor inserted; however, a total of 107 (18%) patients met the definition of raised ICP. The mortality rate for patients with raised ICP was 50.4%. Independent predictors of raised ICP were as follows: age, older than 55 years (odds ratio [OR], 2.26; 95% confidence interval [CI], 1.35-3.76), pupillary fixation (OR, 5.76; 95% CI, 3.16-10.50), signs of significant head trauma (OR, 2.431; 95% CI, 1.39-4.26), and need for intubation (OR, 3.589; 95% CI, 2.10-6.14).

CONCLUSION: This study identified four independent variables associated with raised ICP and incorporated these findings into a preliminary risk assessment scale that can be implemented at the bedside to identify patients at significant risk of raised ICP. Future work is needed to prospectively validate these findings prior to clinical implementation.

LEVEL OF EVIDENCE: Prognostic, Epidemiological, level III.