Are chest radiographs routinely indicated after chest tube removal following cardiac surgery?

OBJECTIVE: The purpose of this prospective study was to determine the incidence and clinical significance of pneumothoraces detected on routine radiography after chest tube removal following cardiac surgery and correlate those findings with an immediate postprocedure assessment of the likelihood of new pneumothorax. SUBJECTS AND METHODS: Routine portable chest radiographs obtained after chest tube removal in 400 consecutive cardiac surgery patients were assessed by a radiologist to determine the incidence and grade of pneumothoraces and were correlated with the clinical estimation of the likelihood of this complication, and whether the radiographic finding changed medical management or led to surgical intervention.
RESULTS: Of 9.3% of cases (37/400) of new pneumothoraces after chest tube removal, 70.3% were tiny (barely perceptible), 27.0% were small (< 1 cm from the pleural line to the apex of the hemithorax), and 2.7% were medium (6-10 cm from the pleural line to the apex of the hemithorax). The incidences of small and medium pneumothoraces were substantially greater in patients with higher levels of clinical suspicion. All tiny pneumothoraces had no clinical importance. Not obtaining routine chest radiographs after chest tube removal in the 345 patients (86.3%) with the lowest level of clinical suspicion would have resulted in missing six small pneumothoraces (1.7%), none of which led to medical or surgical intervention or a delay in discharge.
CONCLUSION: Chest radiography performed after chest tube removal following cardiac surgery is necessary only if the patient has respiratory or hemodynamic changes or if there are problems with the technical aspect of chest tube removal. Following this guideline in our patient population could have eliminated 86.3% of radiographs without missing any clinically significant pneumothoraces.