Management of patients with "ex vacuo" pneumothorax after thoracentesis.

RATIONALE AND OBJECTIVES: To determine clinical outcome in patients who developed "ex vacuo" pneumothorax following thoracentesis and to assess the benefit of chest tube placement for this complication.

MATERIALS AND METHODS: We retrospectively reviewed records of 282 patients who underwent 437 thoracenteses at a single institution during a 6-year period. We identified 34 patients (12.1%) who developed a pneumothorax following 39 thoracenteses (8.8%) and then identified a subset of patients with pneumothorax "ex vacuo" defined as a moderate to large hydropneumothorax or small pneumothorax persisting for more than 3 days. Patient charts were reviewed to document the treatment strategy employed and subsequent clinical outcome, which included length of hospital stay, resolution of pneumothorax, reaccumulation of pleural effusion, and overall survival.

RESULTS: Ten patients developed "ex vacuo" pneumothroax following thoracentesis. None complained of significant worsening of symptoms following thoracentesis. Seven patients were treated by observation alone and 3 patients underwent tube thorocostomy. A decrease in size of the pneumothorax was observed in only 3 patients, none of whom had a chest tube placed. Effusion completely reaccumulated in 7 patients. All 10 patients died during the follow-up period; the mean survival was 157 days (range: 13-402 days). Survival among patients treated by observation was 191.4 days versus 71.7 days for patients receiving chest tubes.

CONCLUSION: Life expectancy for most patients who develop "ex vacuo" pneumothorax following therapeutic thoracentesis is short (<6 months). Chest tube placement is not necessary in asymptomatic patients and is unlikely to provide clinical benefit.