Rib fractures are a commonly suspected and encountered diagnosis in the emergency department. X-rays have long been used to evaluate for the fracture and potential complications, such as a pneumothorax. But they are also widely acknowledged to be insensitive in diagnosing minimally displaced fractures or fractures involving the costal cartilage and costochondral junction.
Ultrasound, on the other hand, has been shown to be highly sensitive in identifying rib fractures, particularly those that are often missed by conventional radiographs. One 2004 study compared ultrasound with chest x-ray and clinical judgment, and found ultrasound to be superior by a wide margin. (J Trauma 2004;56:1211.)
Patients with minor chest trauma are likely to receive a two-view chest x-ray, perhaps with the addition of oblique views. When these images do not show a fracture, many clinicians presume patients with point tenderness to the chest wall have a subtle fracture. These patients are typically treated as outpatients with pain control. Given that many physicians seem to employ this strategy successfully, is it important to definitively diagnose a fracture, perhaps with ultrasound? I would argue yes, for a couple of reasons.
Rib fractures cause significant disability. A 2003 study in the Journal of Trauma followed patients with known rib fractures (isolated, multiple, and associated with other injuries) to determine the course of their symptoms and their return to work. (J Trauma 2003;54:1058.) As expected, patients with multiple injuries had a prolonged course of recovery. Patients with isolated rib fractures, however, were significantly affected by their injuries, with some patients remaining out of work for over a month. Many of them also had significant pain after one month. Being able to make patients aware of the potential prolonged course of their symptoms and the limitations to their recovery gives them a better idea of what to expect and may prevent recurrent ED visits.
Patients with rib fractures often cannot perform normal respiratory activities (deep breathing, coughing to clear secretions) and develop atelectasis as a result. Some of these patients can subsequently develop pneumonia, which can increase their morbidity and mortality. This complication is traditionally most feared in patients with multiple rib fractures, but it deserves consideration in elderly patients with isolated rib fractures or patients with significant pre-existing respiratory illness (COPD, for example). Establishing a definitive diagnosis of one or more fractures may prompt a period of observation for these patients to monitor their respiratory status.
There is another benefit that is more difficult to quantify. Patients obtain more satisfaction from a definitive diagnosis in my experience. Many patients, even after lengthy discussion, seem dissatisfied by a “presumed rib fracture.” I have noted that showing them the fracture on ultrasound has led to a satisfied patient, most of whom suspected this diagnosis themselves and seemed gratified to see it demonstrated before their eyes.
Ultrasound for rib fractures may seem esoteric and unnecessary in a busy ED, but it can make a definitive diagnosis and may have enough benefits to make the time spent worthwhile.
Dr. Butts is the director of the division of emergency ultrasound and a clinical assistant professor of emergency medicine at Louisiana State University at New Orleans.