A-403 Development and evaluation of a new vacuum assist device for capillary blood collection using conventional lancets

Abstract Background Blood collection from sensitive fingertips or difficult-to-locate veins can be technically demanding, as well as a painful and anxiety-inducing experience for patients, limiting access to blood testing outside of clinical settings. Several new lancing devices have been recently developed that simultaneously produce a wound and partial vacuum to collect a capillary blood specimen from alternative sites such as the upper arm. These integrated devices are generally easy to use, nearly painless, and reliable, but can be costly relative to a conventional draw which may impede widespread use. We present a new simplified vacuum assist device that enables use of low-cost conventional lancets to obtain capillary blood specimens from the upper arm or other low-sensitivity locations on the body. Methods A vacuum assist device was designed to enhance capillary blood collection when using conventional single use lancets. The device is molded as a single silicone rubber piece and generates a partial vacuum of about -20kPa when compressed against the body on relatively flat skin surfaces such as the upper arm. The vacuum temporarily adheres the device to the skin and greatly increases capillary blood flow rate from a pre-applied lancet incision. Blood is collected into a removable microvolume tube. The device was evaluated in a pilot study in which a trained professional performed an assisted capillary draw on each of 42 subjects. After 3 minutes of warming the upper arm, a commercial lancet (gentleheel® GHT10X50) was used on the target site, and the silicone rubber vacuum assist device was compressed over the resulting incision. Capillary blood was collected into a BD Microtainer® SST for up to 4 minutes or until collected volume reached 600ul. Blood was also collected by venous phlebotomy into an SST Vacutainer for comparison. All Microtainers were assessed for blood volume, then separated by centrifugation. Each capillary specimen was compared against the subject-matched venous specimen for a variety of analytes including a comprehensive metabolic panel as well as hemolysis using a Roche cobas® 8000 instrument. Results A measurable amount of blood was obtained from 41 out of 42 subjects with 85.4% obtaining at least 400uL (the Microtainer’s minimum fill volume) and 95.1% obtaining at least 100uL of serum after centrifugation. The mean specimen hemolysis index was 4.1 for the capillary serum vs 4.9 for the venous serum. Analytical measurements of the capillary blood specimens agreed (with respect to CLIA acceptance limits) with corresponding measurements of venous specimens at least 80% of the time for all analytes tested other than carbon dioxide (75.0%), glucose (56.7%), potassium (61.5%), and BUN (74.4%). Average subject-rated pain associated with the vacuum assisted capillary draw procedure was 0.39 on a scale of 0 (painless) to 10. Conclusion The vacuum assist device enables a promising and cost-effective method of using conventional lancets to collect capillary blood into microvolume tubes. The procedure involved a minimum of discomfort for tested subjects, and the collected blood specimens produced valid results for many analytes of interest.