To the Editor:-Prevention of needle stick injury is a major issue in the operating room. Various needleless systems are available to avoid this risk. [1,2]We have been using a needleless intravenous access system (InterLink Injection Site; Baxter Healthcare, Deerfield, Ill, and InterLink Syringe Cannula, Becton Dickinson, Franklin Lakes, NJ) in our pediatric intensive care unit and operating room for the past year, and are satisfied, in general. We did however, experience a single incident of skin injury caused by this system.

This incident occurred when a nurse tried to insert a blunt end plastic cannula into the injection site, which currently requires a significantly greater force than that for steel needles. The force cause the tip of the cannula to slip, the momentum causing the tip to scrape the skin on the nurse's finger, causing bleeding.

The blunt end cannula requires only l/2 to 1/3 of the force needed to insert the spikes of infusion sets into infusion containers, but still requires 5-10 times more force to penetrate the injection site than conventional steel needles (Table 1). The working surface of the injection site with the blunt end cannula is relatively small and tends to become slippery after disinfection with wet materials.

Table 1. Force Required to Penetrate

Table 1. Force Required to Penetrate
Table 1. Force Required to Penetrate

The reduced force required to insert a blunt end plastic cannula into the injection site is also desirable to decrease the possibility of accidental dislodging or kinking of catheters. Though the risk of extrinsic blood exposure was small in this case, the potential hazard of needleless systems exists. We encourage manufactures to make the system less slippery and to work with less force required for penetration while keeping the safety advantages.

Katsuyuki Miyasaka, M.D., Tomoo Nakamura, M.D., Hirokazu Sakai, M.D., Department of Anesthesia and Intensive Care Unit, National Children's Hospital, 3-35-31 Taishido, Setagaya Tokyo 154, Japan, Electronic mail:

(Accepted for publication September 12, 1996.)

FDA urges use of recessed-needle or needleless i.v. administration systems [news]. Am J Hosp Pharm 1992; 49:1850-1.
Yassi A, McGill ML, Khokhar JB: Efficacy and cost-effectiveness of a needleless intravenous access system. Am J Infect Control 1995; 23:57-64.