Study objective: To assess the utility of chest
radiograph (CXR) immediately after routine thoracentesis.
Design: Prospective cohort study.
Multispecialty clinic/teaching hospital.
All outpatients and inpatients undergoing thoracentesis in the
procedure area from October 1995 to January 1998.
Measurements: Immediately after thoracentesis, the
physician completed a questionnaire assessing the likelihood of a
complication. CXRs were obtained at physician discretion. Patient
demographics, indications for thoracentesis, use of ultrasound
guidance, level of training, radiographic interpretation, and eventual
patient outcome were recorded.
Results: Two hundred
eighteen patients were enrolled for a total of 278 thoracenteses. Two
hundred fifty-one procedures performed on 199 patients could be
prospectively evaluated. A complication was suspected in 30 procedures;
immediate CXR confirmed such in 9 (30%). There were 221 procedures
with no clinical suspicion or indication of a complication. Ninety CXRs
were obtained immediately after the procedure; the remaining 131
procedures had no CXR. The complication rates were 3.3% and 2.3%,
respectively, for these groups. Four postthoracentesis radiographs
demonstrated additional findings regardless of the indication for the
Conclusions: In the absence of a clinical
indication of a complication, chest radiography is not indicated
immediately after routine thoracentesis. Aspiration of air strongly
correlates with the occurrence of pneumothorax, whereas pain,
hypotension, and dry tap do not. Use of a vacuum bottle to withdraw
fluid obscures the appreciation of this finding and was identified as a
risk factor for subsequent pneumothorax. Additional radiographic
findings are rarely detected and may not contribute to clinical