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 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.