Admission of patients with severe and moderate traumatic brain injury to specialized ICU facilities: a search for triage criteria

Objective: To investigate whether triage for direct admission of patients with traumatic brain injury to a trauma center is facilitated by predicting the risk of potentially removable lesions or raised intracranial pressure (ICP). Design and setting: Cohort study in a level I university trauma center. Patients and participants: A prospective cohort of primarily ( n= 200) and secondarily ( n= 75) referred patients with moderate or severe traumatic brain injury. Measurements and results: Predictive characteristics for the risk of surgically removable lesions and the risk of raised ICP ( repeatedly >= 20 mmHg) were identified and included in prognostic models. These models were validated internally with bootstrapping techniques and externally on a historic sample ( n= 205) regarding discriminative ability (AUC). Among the cohort patients, 67% had raised ICP and 54% had surgically removable lesions. Both outcomes occurred more frequently in patients secondarily referred, but the incidence in patients primarily referred was also high (62% and 33% respectively). No strong predictors of raised ICP were identified. Age and pupillary reactivity were significant predictors of surgically removable lesions. The models discriminated reasonably for surgically removable lesions ( AUC = 0.78 at development and AUC= 0.67 at external validation) but not for raised ICP ( AUC= 0.59 at development and AUC= 0.50 at external validation). Conclusions: It is difficult accurately to identify patients in need of specialized intensive care using baseline characteristics. The high incidence of both outcomes in patients primarily referred support direct admission of more and particularly older patients with severe or moderate brain trauma to level I trauma centers.