Objectives: To correlate patient condition and reasons for obtaining chest radiographs (CXRs) with the utility of CXRs in critical illness and to determine the potential impact of stricter criteria for obtaining a CXR in a surgical intensive care unit (ICU).
Design: Inception cohort study of 1003 CXRs examined prospectively.
Patients and setting: A total of 157 consecutive patients admitted to the general surgical ICU of a 780-bed, urban, university-affiliated, tertiary care hospital.
Intervention: Nothing was done to influence the ordering of CXRs.
Outcome measures: Influence of CXR findings on clinical management.
Results: The likelihood of a clinically important finding was 17% for CXRs obtained for no clear clinical indication (routine), 26% for those obtained to verify the position of a medical device, and 30% for those obtained for suspected clinical conditions. By univariate analysis, suspected pathophysiologic condition, admission APACHE II (Acute Physiology and Chronic Health Evaluation II) score, presence of a central venous or Swan-Ganz catheter, and length of ICU stay were all predictors of a significant finding. By multivariate analysis, the only independent predictor of a finding was a suspected clinical condition, and the only indwelling medical device that was an independent predictor of a finding was a Swan-Ganz catheter. If the criterion that routine CXRs should only be obtained in patients with Swan-Ganz catheters had been used, 200 CXRs would have been avoided during the 3-month study period. The only findings missed by not obtaining those CXRs would have been two malpositioned nasogastric tubes and one malpositioned central venous catheter.
Conclusions: Chest radiographs should only be obtained on surgical ICU patients for specific indications. Routine CXRs for ICU patients are justified only for patients with indwelling Swan-Ganz catheters.