Timing waveform analysis

PURPOSE: To determine the diagnostic yield of routine admission chest radiographs in patients with acute gastrointestinal (GI) hemorrhage and clinical predictors of radiographic abnormalities. PATIENTS AND METHODS: The study was a retrospective series of 202 adult patients with GI hemorrhage admitted to intensive care units at an academic medical center. Routine admission chest radiographs were obtained in 161 patients. These radiographs were reviewed by a study radiologist blinded to the study purpose. The radiologist scored radiographic abnormalities into categories of "minor" or "major," "new" or "previously known," and "with an intervention" or "without an intervention." Nominal logistic regression explored the data for clinical features that identified patients with major new radiographic abnormalities with or without an intervention. RESULTS: Minor radiographic abnormalities were noted in 23 (14.3%) patients, of whom 17 (10.6%) patients had "new" (previously unknown) abnormalities. No minor abnormality prompted a therapeutic or diagnostic intervention. Major radiographic abnormalities were detected in 21 (13.0%) patients, of whom 19 (11.8%) had new findings. Major new findings prompted interventions in only 9 (5.6%) of patients. A history of lung disease and an abnormal lung physical examination predicted major new radiographic findings (P = 0.0001, sensitivity 79%, negative predictive value 96%). These variables also identified major new abnormalities that prompted interventions (P = 0.007, sensitivity 89%, negative predictive value 99%). Use of the logistic regression model to select patients for admission chest radiographs decreased charges from $1,068 to $580 for each detected major new radiographic abnormality and from $2,254 to $1,087 for major new radiographic abnormalities that prompted an intervention. CONCLUSION: These data indicate that routine chest radiographs have a low yield in detecting major new radiographic abnormalities in patients with acute GI hemorrhage. Clinical criteria, available at the time of admission, may be useful for selecting patients for chest radiographic evaluations.