September 1, 2018
Two of the most important organs in the body, the heart and lungs, are protected by a bony cage created by the ribs and attached muscles. The rib cage comprises 12 ribs on each hemithorax: seven ribs attached to the midline sternum, three ribs attached to the sternum through costal cartilage, and two floating ribs. The attached muscle layers protect the heart and lungs but also aid in the ever-important task of breathing.
Rib fractures can be classified as single, multiple, displaced, or non-displaced. A flail segment by definition is a chest wall deformity that contains at least two fractures per rib in at least two consecutive ribs. The most common mechanism causing a rib fracture or a break in the cage is a direct blow to the rib from blunt trauma. Of the patients admitted to the hospital with blunt chest trauma, approximately 10 percent will have at least one rib fracture.1 The fourth through 10th ribs are the most commonly fractured, while a fracture of ribs one through three is often associated with a high-energy mechanism of injury.2
Rib fractures may be diagnosed from the physical exam findings of bruising, abrasions, or seat belt signs on inspection; however, on palpation, one may find crepitus, point tenderness, or elicit pain with inspiration or coughing. A chest X ray can identify approximately 50 percent of rib fractures, whereas a computed tomography (CT) scan is much more sensitive in diagnosing fractures. A CT scan has the added advantage of imaging potential secondary injuries caused by the broken rib.1,2 Additional traumatic findings associated with rib fractures include: pneumothorax, hemothorax, pulmonary contusion, or laceration of the spleen or liver.
To examine the occurrence of patients with rib fractures in the National Trauma Data Bank® (NTDB®) admission year 2016, medical records were searched using the International Classification of Diseases, 10th Revision Clinical Modification codes. Specifically searched were records that contained a diagnosis code of either S22.3 (fracture of one rib), S22.4 (multiple fractures of ribs), or S22.5 (flail chest). A total of 123,491 records were found, of which 111,418 contained a discharge status, including 71,032 patients discharged to home, 19,471 to acute care/rehab, and 14,866 to skilled nursing facilities; 6,049 died (see Figure 1). Of these patients, 67 percent were male, an average of 58.8 years old, had an average hospital length of stay of 7.7 days, an intensive care unit length of stay of 6.7 days, an average injury severity score of 16.7, and were on the ventilator for an average of 7.8 days. Of the patients tested, 29 percent (19,720 out of 68,812) tested positive for alcohol.
As one might expect, thoracic trauma, including rib fractures, is associated with several complications. According to a 2012 NTDB study, as the number of ribs fractured increased, so did the risk for pneumonia, acute respiratory distress syndrome, pneumothorax, increased hospital length of stay, and mortality.3 The risk factors for mortality in thoracic trauma are age greater than 65, greater than three rib fractures, and premorbid cardiopulmonary disease.4 Breaking the cage should not be taken lightly.
Throughout the year, NTDB data are highlighted through brief monthly reports in the Bulletin. The NTDB Annual Report can be found on the American College of Surgeons website as a PDF file. In addition, the website contains information about how to obtain NTDB data for more detailed study. To submit your trauma center’s data, contact Melanie L. Neal, Manager, NTDB, at mneal@facs.org.
Statistical support for this column was provided by Ryan Murphy, Data Analyst, NTDB.
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