Is posttraumatic cerebrospinal fluid fistula a predictor of posttraumatic meningitis? A US Nationwide Inpatient Sample database study.

OBJECT: Various factors have been reported in literature to be associated with the development of posttraumatic meningitis. There is a paucity of data regarding skull fractures and facial fractures leading to CSF leaks and their association with the development of meningitis. The primary objective of this study was to analyze the US Nationwide Inpatient Sample (NIS) database to elucidate the factors associated with the development of posttraumatic meningitis. A secondary goal was to analyze the overall hospitalization cost related to posttraumatic meningitis and factors associated with that cost.

METHODS: The NIS database was analyzed to identify patients admitted to hospitals with a diagnosis of head injury from 2005 through 2009. This data set was analyzed to assess the relationship of various clinical parameters that may affect the development of posttraumatic meningitis using binary logistic regression models. Additionally, the overall hospitalization cost for the head injury patients who did not undergo any neurosurgical intervention was further categorized into quartile groups, and a regression model was created to analyze various factors responsible for escalating the overall cost of the hospital stay.

RESULTS: A total of 382,267 inpatient admissions for head injury were analyzed for the 2005-2009 period. Meningitis was reported in 0.2% of these cases (708 cases). Closed skull base fractures, open skull base fractures, cranial vault fractures, and maxillofacial fractures were reported in 20,524 (5.4%), 1089 (0.3%), 5064 (1.3%), and 88,649 (23.2%) patients, respectively. Among these patients with fractures, meningitis was noted in 0.17%, 0.18%, 0.05%, and 0.10% admissions, respectively. Cerebrospinal fluid rhinorrhea was reported in 453 head injury patients (0.1%) and CSF otorrhea in 582 (0.2%). Of the patients reported to have CSF rhinorrhea, 35 (7.7%) developed meningitis, whereas in the cohort with CSF otorrhea, 15 patients (2.6%) developed meningitis. Cerebrospinal fluid rhinorrhea (p < 0.001, OR 22.8, 95% CI 15.6-33.3), CSF otorrhea (p < 0.001, OR 9.2, 95% CI 5.2-16.09), and major neurosurgical procedures (p < 0.001, OR 5.6, 95% CI 4.8-6.5) were independent predictors of meningitis. Further, CSF rhinorrhea (p < 0.001, OR 2.0, 95% CI 1.6-2.7), CSF otorrhea (p < 0.001, OR 2.3, 95% CI 1.9-2.7), and posttraumatic meningitis (p < 0.001, OR 3.1, 95% CI 2.5-3.8) were independent factors responsible for escalating the cost of head injury in cases not requiring any major neurosurgical intervention.

CONCLUSIONS: Cerebrospinal fluid rhinorrhea and CSF otorrhea are independent predictors of posttraumatic meningitis. Furthermore, meningitis and CSF fistulas may independently lead to significantly increased cost of hospitalization in head injury patients not undergoing any major neurosurgical intervention.