From bedside to bench: A pilot study to measure the force required to activate a retractable safety syringe

Abstract

BACKGROUND/OBJECTIVES: This laboratory in Tampa, Florida, has established a program to evaluate objective and subjective criteria for safer needle devices designed to prevent or reduce sharps injuries in healthcare workers. The goal of this pilot study was to determine whether the force required to activate one particular retractable intramuscular syringe was due to the activation media or the healthcare worker. METHODS: One hundred devices of a particular brand were subjected to activation while suspended in the air and while the needle was inserted into simulated patient material (SPM). Each researcher tested 25 devices in air first and 25 in SPM first, resetting the device before switching media. After each activation, the compression force needed to activate the retraction mechanism on each individual syringe was measured in pounds (lbs.) using a Com-Ten™ Model # CER02000 Digital Force Gauge (DFG). The data were immediately recorded in an Excel™ spreadsheet. RESULTS: Overall, the mean activation force was significantly greater (p = 0.05) while the needle was activated in SPM (3.56 lbs.) versus air (2.80 lbs.), regardless of the sequence or researcher. In addition, there was a statistically significant difference, regardless of sequence, in the device's mean activation force between researchers 1 and 2 (2.78 lbs. versus 3.57 lbs.; p = 0.05). CONCLUSIONS: In healthcare settings, the force required to activate the device is clinically relevant. If a healthcare worker perceives that force required to activate the device equates with pain felt by the patient, then the HCW may activate the device while in the air, increasing the risk of sharps injury. This would also defeat the purpose of this particular safety mechanism, of particular concern as this category of device generally costs more than other safety intramuscular syringes. We demonstrated a significant difference in mean force using one particular device due to the media in which the device was activated. This has implications for manufacturers in designing future models. Significant variability existed between healthcare workers in the force necessary to activate the retractable mechanism of an intramuscular device. In future studies of this kind, we recommend that one researcher be used in initial pilot studies in the laboratory setting. Finally, the phenomenon of perceived versus exerted force and whether force equates with pain are two areas for potential future studies.