Abstract: A system for draining a wound including an elongated flexible catheter tube, an evacuated collection container and an adapter connecting the catheter tube to the container. The container has a pierceable stopper, and the adapter includes a projecting hollow needle and a pair of arcuate guide flanges disposed along opposite sides of the needle. As the adapter is moved into position on the container, the arcuate flanges move along the periphery of the stopper and the needle pierces the stopper. A graduated translucent protective tubular housing receives the container, the housing having arcuate internal surfaces frictionally engaging external surfaces of the guide flanges to retain the adapter in the housing. The adapter includes gripping portions extending beyond the housing and gaps exposing the stopper, so that the adapter may be removed from the container while the stopper is held in place.