N. O. Shulzhenko1, H. Jung1, M. V. Beems1, T. J. Zens1, A. P. O’Rourke1, A. E. Liepert1, J. E. Scarborough1, S. K. Agarwal1 1University Of Wisconsin,Department Of Surgery,Madison, WI, USA
Introduction:
Rib fractures have been previously associated with significant morbidity and mortality in injured older adults. Contemporary studies have reported that when adjusted for age, comorbidities and trauma burden, the number of rib fractures is not associated with worse outcomes. Our study sought to investigate this risk-adjusted relationship in older adults. We hypothesized that, in an older adult population, the number of rib fractures was a predictor of worse outcomes independent of patient comorbidities and trauma burden.
Methods:
A retrospective review of the prospectively collected American College of Surgeons’ National Trauma Data Bank registry was performed for all patients 65 years of age and older who had sustained rib fractures between 2009 and 2012. Patients with accompanying sternal fractures, penetrating or burn mechanisms, and those with missing data on the number of rib fractures were excluded for a total study cohort of 67,695 patients. Data were collected for age, gender, injury severity score, mechanism of injury, comorbidities, number of rib fractures, hospital mortality, hospital and ICU lengths of stay (LOS), need for ICU care, need for ventilator support, and ventilator duration. Data were also collected for the occurrence of any complication, the occurrence of any pulmonary complication; as well as the occurrence individually of pneumonia, acute respiratory distress syndrome (ARDS), and unplanned intubation. To account for International Classification of Diseases defined database coding, rib fracture data was modeled both as an ordinal variable with groups (1-2, 3-5, 6-7, 8+ fractures) and as an interval variable (one to seven). Bivariate analysis was performed with all candidate predictor and outcome pairs to identify significant factors (α<0.1) to include in multivariate models. Multivariate logistic regression analysis was then performed for all dichotomous outcomes and log-transformed multiple linear regression analysis was performed for all continuous outcomes.
Results:
Eight or more rib fractures were independently associated with hospital mortality, ICU LOS, need for mechanical ventilation, ventilator duration, pulmonary complications, ARDS, and unplanned intubation (p<0.001). Six or more rib fractures were independently associated with LOS, need for ICU care, overall complications, and pneumonia (p<0.001). In a subset excluding patients with serious injuries (AIS>2) in body regions other than the chest, six or more rib fractures were independently associated with all outcomes except for ventilator duration (p<0.03). In this subset, every additional rib fracture increased LOS and the need for ICU care (p<0.03).
Conclusion:
In older adults, the number of rib fractures is a significant predictor of trauma outcomes independent of comorbidities and trauma burden. It is unclear whether rib fractures in isolation cause the outcomes measured or are an independent variable for injury severity.