Age and adverse outcomes in rib fracture patients.

There are five principle determinants of outcome following serious injury: injury severity, age, pre-existing medical conditions, time from injury to definitive care, and quality of care. Increasing age increases mortality following trauma, and the only debatable point is the age at which the enhanced mortality risk becomes manifest. In the most recent study of this phenomenon, over 5,000 injured patients from Germany were reported by Kuhne et al (1) They defined 56 years as the threshold from which mortality increased significantly in patients who sustained multisystem trauma, and the increased risk of death was independent of trauma severity.

In the current report by Testerman, (2) the risk of complications and death was assessed in a retrospective review of 307 patients who sustained rib fractures from blunt trauma. Confounding variables were minimized to more clearly define the role of both the number of rib fractures and patient age in determining outcome. The thresholds of both absolute number of rib fractures, (four or less; more than four), and of patient age, (45 yr), were arbitrary, but appear to be supported by the data. Could these arbitrary cut-offs be changed by a rib fracture or two one way or the other? Probably. Likewise, could the age of increased risk actually be 44 or 46? Let's not quibble. The significance of this study is to heighten the clinician's awareness that rib fractures confer an enhanced risk of adverse outcome for patients otherwise not regarded as especially vulnerable.

However, as with any good study, more questions are raised than answered. Is it the absolute number of rib fractures or the age of the patient which is the greater determinant of outcome? Most authorities would come down on the side of injury severity (rib fracture number) as the leading outcome determinant, but this study supports both age and number of rib fractures as covariables of increased risk in older patients, with greater than four rib fractures clearly indicating greatest risk. It is somewhat surprising that there were similar complication rates in patients with 4 or fewer rib fractures, regardless of age. It is counterintuitive to believe that a 40-year-old and an 80-year-old patient with typical comorbidities would be similarly affected following blunt trauma resulting in four rib fractures. This study was neither designed nor empowered to make these types of discriminations, and thereby underlies the weakness of this report. My other concern relates to flail chest injury. With an increasing number of rib fractures, one would expect to encounter segmental chest wall instability which confers an added clinical risk from pulmonary contusion, paradoxical motion, and hypoventilation. The author does not comment on whether study patients sustained a flail chest and, if so, whether such patients were equally represented in both age groups. Despite these concerns, this report highlights an important message about a common clinical problem.

References

1. Kuhne CA, Ruchholtz S, Kaiser GM, et al. Mortality in severely injured elderly trauma patients: when does age become a risk factor? World J Surg 2005;29:1476-1482.

2. Testerman G. Adverse outcomes in younger rib fracture patients. South Med J 2006;99:335-339.

Kimball I. Maull, MD

From the Department of Surgical Education, Carraway Methodist Medical Center, Birmingham, AL

Reprint requests to Kimball I. Maull, MD, Department of Surgical Education, Carraway Methodist Medical Center, 1600 Carraway Boulevard, Birmingham, AL 35234. Email: [e-mail]

Accepted January 17, 2006.