What is the key question?

• Does gravity drainage protect against negative pressure-related complications such as chest discomfort, re-expansion pulmonary edema, or pneumothorax compared with active aspiration?

What is the bottom line?

• Investigators designed a prospective, multicenter, single-blind, randomized controlled trial where they randomized patients with large free-flowing effusions (estimated ≥ 500 mL) 1:1 to undergo active aspiration (using a 60-ml syringe) versus gravity drainage.
• Patients rated chest discomfort on 100-mm visual analog scales (VAS) prior to, during, and following drainage. Thoracentesis was stopped at complete evacuation or for persistent chest discomfort, intractable cough, or other complication. The primary outcome was overall procedural chest discomfort scored 5 minutes following the procedure. Secondary outcomes included measures of discomfort and breathlessness through 48 hours post-procedure.
• A total of 142 patients were randomized to undergo treatment, with 140 in the final analysis. Groups did not differ for the primary outcome (mean VAS score difference, 5.3 mm; 95% CI, –2.4 to 13.0; P = 0.17). Secondary outcomes of discomfort and dyspnea did not differ between groups.
• Comparable volumes were drained in both groups but the procedure duration was significantly longer in the gravity arm (mean difference, 7.4 min; 95% CI, 10.2 to 4.6; P < 0.001). There were no serious complications.

Why read on?

• This study shows that large-volume thoracentesis via active aspiration and gravity drainage are both safe and result in comparable levels of procedural comfort and dyspnea improvement. They can both be offered to patients. Overall, active aspiration requires less total procedural time.