Assessing blunt cannulae as replacements for hypodermic needles during intravenous therapy: safety and utility

Recently, blunt 18-gauge (ga) metal cannulae have become nationally commercially available as safety products. The ability of these blunt cannulae to prevent needlestick injury and to enable direct access of all standard latex ports and vial membranes, thus eliminating hypodermic needles entirely from the intravenous (i.v.) drug administration process, is assessed.

In the laboratory setting, the needlestick injury potential of small-bore blunt cannulae versus hypodermic needles was studied using blinded and randomized methods. Insertion force requirements were studied for cannulae and needles. Metal 18-ga blunt cannulae were inserted into four brands of standard Y-ports and vial stoppers to assess postpuncture integrity and force requirements.

Needlestick injury did not occur using small-bore blunt cannulae (P < .001; n = 51). Metal 18-ga cannulae passed into prepierced standard Y-ports as easily as hypodermic needles and without loss of Y-port integrity. Insertion of metal 18-ga cannulae without prior port puncture was possible, but was associated with substantial coring and loss of integrity of the port seal, except for IVAC brand ports (P < .03).

Metal 18-ga cannulae can be inserted through virtually all intact standard rubber vial membranes or standard Y-ports to allow safe IV access. A single prepuncture of any standard latex membrane allows economical blunt metal cannula access equally efficiently as with expensive pre-slit membranes and without loss of membrane integrity.