The reported wound problems of these trials included severe oozing,
bruising, blistering, partial breakdown, wound infection, and cellulitis. Another study
reported an episode of transient hypotension upon release of the drain that resolved
spontaneously.(Kiely et al. 2001) Again, no significant difference was found between the
clamping and non-clamping groups regarding these complications.
In summary, the available evidence indicated that temporarily clamping the drains after
TKA decreased the volume of drainage, but only clamping for not less than four hours
decreased the reduction in hemoglobin levels. Although clamping does not increase the
complication rate, its effectiveness and necessity is still questionable.