Blood drawing device with flash detection

A device for drawing fluid from a lumen, and particularly blood from a blood vessel, is disclosed. The device may provide indication of the entry of an intravenous cannula into the lumen. The device may include a central body having an outer wall and an inner fluid passage. The device may include a luer-type adapter to permit the attachment of an I.V. infusion set of various lengths (“butterfly needle”) and or any luer-type fitting attached to an existing device. The outer wall of the central body may be transparent or translucent to permit the detection of fluid within the inner fluid passage. A front cannula may extend from one end of the central body and a rear cannula may extend from the other end of the central body. Both the front and rear cannulae may communicate with the inner fluid passage. A transparent or translucent flexible sleeve may surround at least a tip portion of the rear cannula. A venting member may be provided near a base portion of the rear cannula between the flexible sleeve and the ambient. The venting member may permit the passage of air through it, but be substantially impermeable to liquids, such as blood.