Background: Closed-suction drains are widely used to reduce the incidence of seroma whenever potential spaces are surgically created. However, few studies have examined the parameters that affect drain efficacy.
Methods: An in vitro model was created to assess the effects of tubing length, tubing size, tubing type, fluid viscosity, fluid clotting, evacuator type, evacuator squeeze method, evacuator fill, and evacuator pressure on the performance of closed-suction drains.
Results: Fluid flow rate through the drain increases with increasing intracavitary tubing length, decreasing extracavitary tubing length, increasing tubing diameter, increasing negative pressure, decreasing fluid viscosity, and the use of perforated rather than fluted drains. Bulbs generate more effective suction when squeezed "side-to-side" than when squeezed "bottom-up," and evacuators were only able to generate half the maximal negative pressure when 25 percent full or greater. Stripping the drain tubing helped relieve obstruction caused by clotting.
Conclusions: The authors' findings have practical clinical implications for surgeons hoping to maximize the efficacy of closed-suction drains. Through this comprehensive review of the literature and in vitro analysis of relevant variables that affect drain function, the performance of closed-suction drains can be optimized by increasing intracavitary tubing length, decreasing extracavitary tubing length, increasing tubing diameter, increasing the pressure differential, using perforated drains, squeezing bulbs side-to-side, stripping drain tubing frequently, and evacuating containers whenever they are 25 percent full.
Clinical question/level of evidence: Therapeutic, V.