Does the expiratory view in chest X-rays contribute to the diagnosis of suspected pneumothorax in the emergency department?

ABSTRACT

To evaluate the contribution of chest X-ray's [expiratory view] in the diagnosis of pneumothorax. In addition, to evaluate the clinical significance, and the need for emergency interventions, for those pneumothoracies that are missed when reading 2 views, inspiratory and lateral only, versus 3 views, inspiratory, expiratory and lateral. One-hundred and sixty-five groups of three X-ray chest views [inspiratory, lateral and expiratory] that had been ordered to rule-out pneumothorax, over a 2 year period at St. Joseph's Hospital Emergency Department in Hamilton, Ontario, Canada. In the first part of the study, the 2 views, inspiratory and lateral, were reviewed independently by two emergency staff and two emergency residents; expiratory view was excluded. In the second part of the study, at least 6 weeks later, the same four physicians reviewed the three views. Charts were reviewed for patients that were had a pneumothorax, according to the radiologist's diagnosis, and were missed by any of the four readers. Clinical significance and interventions were documented, i.e. admission for observation, needle aspiration and chest tube insertion. Using Kappa and correlation analysis, the agreement between the physicians and radiologist is significantly greater when three views are read relative to when only two views are read. Of all pneumothoracies, 28.5% were missed when the two views were used compared to 19% when three views were used. These results suggest that we still need 3 views to rule-out clinically significant pneumothrax in the emergency department. However, 2 views may be enough if a radiologist reads them