Needles are the most widely used medical device, with an estimated 16 billion injections administered each year. Exposure of blood-borne pathogens by needle-stick injuries (NSI) is a risk to healthcare professionals, and has led to legislation in the US mandating the use of needle-safety devices.
Prior to legislation, an estimated 385,000 NSIs occurred annually. The total residual volume of medication in the cannula, hub or Luer of the needle following injection is termed the 'dead space' of the needle and syringe, and can increase due to the safety features added to minimise NSIs. Reductions in dead space can improve safety and reduce medication waste in commonly injected medication, expensive drugs and certain vaccinations, by increasing the number of doses extracted per vial.
Much of this information came to light in Hauri AM et al's study, 'The global burden of disease attributable to contaminated injections given in healthcare settings', which compared the amount of dead space in six hypodermic safety needles. Assessment of average dead space was performed by independent testing laboratory Analytical Answers.
Syringes and 23-gauge needles were assembled using hand tightening, and then the syringes were filled with approximately 1cc distilled water through the needle and any residual air was removed. The water was dispensed into a beaker, the mass of the syringe needle combination measured and the residual volume of water calculated (see table 1, above). Smiths Medical's had the smallest average dead space volume, with its competitors containing 9-57% more dead space.
The decreased dead space in the Needle-Pro EDGE Safety Device can lead to considerable cost savings for healthcare providers (see table 2, right). When injecting the flu vaccine, a 5.0ml multidose vial is often used to administer 0.5ml doses. If the dead space typical to each 23-gauge needle is taken into consideration, the vials containing 5ml (ten doses) can only administer a full eight doses in the Competitor 3, 4 and 5 needles. The Needle-Pro EDGE Safety Device can inject a full nine doses using the same vial and dose.
The economic impacts of dead space are significant when dispensing high-priced medications, or during a drug shortage. Many drugs, including vaccines, oncologic agents and medications provided to end-stage renal disease (ESRD) patients would apply to this principle, especially those prepared from multidose vials.
Situations that involve expensive medications, and those with direct nursing preparation and administration, may be of the highest value. This includes a dialysis clinic for Epoetin administration or a Synagis clinic for respiratory syncytial virus prevention in at-risk paediatric patients. In these situations, multidose vials may be shared between patients, and minimising dead space allows the facility to provide the needed therapy while minimising costs.
Comparing the use of Smiths Medical's Needle-Pro EDGE device for Epoetin injection with five competitor needles, the Needle-Pro EDGE Safety Device would allow four doses of Epoetin for an average adult-sized patient following dialysis, versus only three doses from other needles. This would offer significant savings to the dialysis provider secondary to the ESRD payment bundle.
The Needle-Pro EDGE Safety Device retains the least amount of dead space compared with five other hypodermic safety-needle devices, suggesting an improvement in safety and cost savings.
