1. Occult Pneumothoraces in Acute Trauma Patients
- Author
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Chad Berryman, Steven J. Weiss, William A. McIntyre, and Amy A. Ernst
- Subjects
emergency medicine ,emergency department ,pneumothoraces ,trauma ,Medicine ,Medical emergencies. Critical care. Intensive care. First aid ,RC86-88.9 - Abstract
Introduction: Many traumatic pneumothoraces (PTX) are not seen on initial chest radiograph (CR)(occult PTX) but are detected only on computed tomography (CT). Although CR remains the first toolfor detecting PTX, most trauma patients with significant thoracoabdominal injuries will receive both CTand CR. The primary objective of this study was to retrospectively determine the effectiveness of CR fordetecting PTX in trauma patients. Our hypotheses were that CR is a sensitive indicator of PTX on CT,that chest pain and shortness of breath are good predictors of PTX on CR, and that we could determineother predictors of PTX on CR.Methods: All trauma patients presenting to our Level I trauma center with a CT-diagnosed PTX over a2-year period who had both a CR and a chest CT were included. The CT reading was considered thegold standard for PTX diagnosis. Electronic medical records were searched using key words fordiagnoses, symptoms, demographics, and radiologic results. We recorded the official radiologistreadings for both CR and CT (positive or negative) and the size of the PTX on CT (large, moderate,small, or tiny). The outcome variable was dichotomized based on presence or absence of PTXdetected on CR. Descriptive statistics and v2 tests were used for univariate analysis. A regressionanalysis was performed to determine characteristics predictive of a PTX on CR, and 1 variable wasadded to the model for every 10 positive CRs. With equal-size groups, this study has the power of 80%to detect a 10% absolute difference in single predictors of PTX on CR with 45 subjects in each group.Results: There were 134 CT-documented PTXs included in the study. Mean age was 42, and 74%were men. For 66 (49%) patients, PTX was detected on CR (sensitivity¼50%). The CR detected 30%of small PTX, 35% of moderate PTX, and 33% of large PTX. Comparing patients with and without PTXon CR, there were no significant differences in shortness of breath or chest pain. There no relationshipsbetween PTX detected on CR and age, gender, penetrating versus blunt injury, bilaterality of the PTX,or presence of lung contusion or hemothorax on CT. After adjusting for all significant variables,predictor of a PTX detected on CR was air in the tissue on CR (adjusted odds ratio [OR]¼3.8) and PTXsize (compared to a tiny PTX, adjusted OR¼2.0 for a small PTX, 7.5 for a moderate PTX, and 51 for alarge PTX). Chest tubes were used in 89% of patients with PTX on CR and 44% of patients with PTXonly on CT (difference 45%; 95% confidence interval 30, 58).Conclusion: Factors associated with PTX on CR included air in the soft tissue on CR and size of thePTX. Even when PTX is not apparent on CR, 44% of these PTXs received placement of a chest tube.
- Published
- 2012