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The following is a summary of “Gravity- vs Wall Suction-Driven Large-Volume Thoracentesis: A Randomized Controlled Study,” published in the July 2024 issue of Pulmonology by Shojaee et al.
Previous research has indicated no significant difference in chest discomfort between patients undergoing manual syringe aspiration versus gravity drainage following thoracentesis. However, it remains unclear whether gravity drainage offers protection against chest pain compared to wall suction, which creates a larger negative pressure gradient. This study aimed to determine whether wall suction drainage induces greater chest discomfort than gravity drainage in patients undergoing large-volume thoracentesis.
In this multicenter, single-blinded, randomized controlled trial, patients with large, free-flowing pleural effusions of ≥500 mL were randomly assigned in a 1:1 ratio to either wall suction or gravity drainage. Wall suction was conducted using a suction system with the vacuum pressure set to full, while gravity drainage involved placing a drainage bag 100 cm below the catheter insertion site, connected with straight tubing. Patients assessed their chest discomfort using a 100-mm visual analog scale before, during, and after the procedure. The primary outcome was the level of postprocedural chest discomfort measured at 5 minutes, with secondary outcomes including overall postprocedural discomfort, breathlessness, procedure duration, fluid volume drained, and complication rates.
Out of 228 initially randomized patients, 221 were included in the final analysis. The primary outcome of procedural chest discomfort did not show a significant difference between the wall suction and gravity drainage groups (p = 0.08). Additionally, secondary outcomes such as postprocedural discomfort and dyspnea were similar across both groups. Both techniques achieved comparable fluid drainage volumes, although the gravity drainage procedure took approximately 3 minutes longer. The incidence of complications, including pneumothorax and re-expansion pulmonary edema, was similar between the two drainage methods.
In conclusion, wall suction drainage does not significantly increase chest discomfort compared to gravity drainage despite the larger negative pressure gradient associated with wall suction. Both methods demonstrate comparable safety profiles and effectiveness, with the choice of technique potentially influenced by procedural preferences and logistical considerations.
Source: sciencedirect.com/science/article/abs/pii/S0012369224046178
