R. Guyer1,2, B. Dennis2, O. Gunter2, O. Guillamondegui2 1Massachusetts General Hospital,Boston, MA, USA 2Vanderbilt University Medical Center,Nashville, TN, USA
Introduction: Prior studies have shown that the number of rib fractures strongly predicts morbidity and mortality, especially in elderly patients. Current therapy for rib fractures focuses on adequate analgesia. It is unknown whether improved care has affected morbidity and mortality in rib fracture patients or has attenuated the risk conferred by age. We readdressed the relationship between the number of rib factures and clinical outcomes in a modern population. We hypothesized that the number of rib fractures is associated with mortality and pneumonia. We also hypothesized that age and ISS would both predict mortality and pneumonia.
Methods: This is a retrospective review of adults admitted to a Level I academic trauma service with at least one rib fracture over five years. Pregnant patients were excluded. Patient characteristics included age, ISS, number of rib fractures, and associated injuries. The primary outcome measure was mortality, and pneumonia was a secondary outcome. A multivariate analysis was performed for outcome measures controlling for patient characteristics, injury severity, associated diagnoses/procedures, and pain control modality.
Results: Of the 4631 patients studied, the median age was 50 (IQR 30-64); 23% were elderly (>65). Median ISS was 22, pneumothorax was seen in 38%, and hemothorax in 19%. Pneumonia was diagnosed in 8%, and overall mortality was 8%. 17% of patients were given an epidural catheter, 40% were given patient-controlled analgesia, and 0.2% underwent a nerve block procedure. We found no association between the number of rib fractures and either mortality or pneumonia among either elderly or non-elderly patients. Elderly patients comprised a significantly greater fraction of decedents than of survivors (47% vs 21%, p<0.001). Patients who died had a higher ISS (36 vs 21, p<0.01), and were more likely to have a pneumothorax (47% vs 37%, p<0.01), a hemothorax (28% vs 19%, p<0.01), and pneumonia (15% vs 7%, p<0.01). Patients who died were significantly less likely to receive either an epidural (10% vs 17%, p<0.01) or PCA (10% vs 43%, p<0.01). Patients who developed pneumonia had a higher ISS (34 vs 22, p<0.01), were more likely to have a pneumothorax (52% vs 37%, p<0.01), and were more likely to have a hemothorax (28% vs 19%, p<0.01). On multivariate analysis, age was a risk factor for mortality (OR 1.05, 95% CI 1.04-1.05) and patients with epidural catheters (OR 0.36 95% CI, 0.23-0.56) or PCA (OR 0.16 95% CI, 0.11-0.24) were less likely to die.
Conclusion: In this study of a modern population of trauma patients with rib fractures, we found that the number of fractured ribs did not predict outcomes. Age and injury severity were both predictors of mortality, and injury severity was a predictor of pneumonia. Contemporary management practices may have eliminated the stepwise risk of mortality and morbidity associated with each rib fracture. Future studies are needed to identify modifiable risk factors.