A pilot study to measure the compressive and tensile forces required to use retractable intramuscular safety syringes

Background: A pilot study was conducted at the Tampa Veterans Administration Patient Safety Center. The objective was to determine the forces required to operate retractable safety syringes to evaluate potential adverse occupational health and patient safety issues. Methods: Four brands (100 each) of retractable syringes were tested, using a digital force gauge, in air and in a simulated patient material (SPM). Compressive and tensile forces were measured while activating the retraction mechanism and withdrawing saline into the syringe barrel, respectively. Results: The mean compressive force was greater in SPM than in air in all 4 devices. There was a statistically significant compressive force difference between activation in air and SPM in devices 1 and 2 (P <= .05). The tensile forces for all devices were lower than the compressive forces. Analysis of variance was used to compare the groups, and the results showed that the means were significantly different (P < .001). Conclusion: This pilot study has implications for device selection, training for users, design issues for manufacturers, and patient safety, as well as potential for future needlestick and ergonomic injuries. We recommend replication of this study with a computer-controlled force testing apparatus, and by testing multiple needle and syringe sizes.