US-guided thoracentesis: Requirement for postprocedure chest radiography in patients who receive mechanical ventilation versus patients who breathe spontaneously

PURPOSE: To identify a population of patients who may not need chest radiography after diagnostic thoracentesis by assessing and comparing the pneumothorax rates in patients with mechanical ventilation (intubation) versus spontaneously breathing patients (no intubation). MATERIALS AND METHODS: A retrospective review of all radiographs, clinical records, and ultrasound (US) scans obtained in 434 patients who underwent US-guided thoracentesis was performed. Three hundred forty-two patients were not intubated and 92 were intubated. Nine patients were excluded because of preexisting pneumothorax. The size of the effusion, the needle size used, and whether a pneumothorax occurred after the procedure were determined. RESULTS: Results demonstrated that only 10 pneumothoraces occurred (six in intubated and four in nonintubated patients). None of the nonintubated patients with pneumothorax and two of the six intubated patients with pneumothorax needed chest tubes. The difference in the pneumothorax rate between intubated and nonintubated patients was statistically significant (P <.01). CONCLUSION: Spontaneously breathing patients who undergo diagnostic thoracentesis do not need postprocedure chest radiography.