A lancing device is a specialized, spring-loaded instrument designed to obtain a small capillary blood sample for testing purposes. This process, often referred to as a “fingerstick,” is primarily used by individuals to monitor their blood glucose levels for diabetes management. The device works by housing a tiny, sharp, single-use needle, called a lancet, and automatically retracting it after use, which makes the procedure much quicker and more controlled than a manual prick. Modern lancing devices are engineered to minimize the pain and discomfort associated with frequent blood sampling.
Preparation: Loading and Adjusting the Device
Before using the lancing device, it must be prepared with a new, sterile lancet. The first step involves removing the cap from the lancing device, often by twisting and pulling it off. Next, a fresh lancet is inserted firmly into the holder inside the device until it is fully seated or clicks into place. The sterility of the lancet is maintained by a protective cap, which must be twisted off and saved for later disposal of the used needle.
Once the lancet is secured and its protective cover is removed, the lancing device cap is replaced, ensuring it is securely fastened. This cap usually contains an adjustable dial or mechanism to control the depth of skin penetration. Devices typically offer several settings, with lower numbers (e.g., 1 or 2) corresponding to a shallower puncture, suitable for thinner or more sensitive skin. Higher numbers (e.g., 5 or 6) are used for thicker or calloused skin to ensure an adequate blood sample.
It is recommended to start with a medium-low setting, such as 3, and adjust upward only if a sufficient blood drop is not produced. Finally, the device must be “cocked” or primed, which involves pulling back a plunger or arming barrel until a click is heard. This indicates the internal spring mechanism is ready to fire quickly and accurately when the release button is pressed.
Execution: The Proper Lancing Technique
The actual technique of using the lancing device begins with selecting the optimal site for sampling. The sides of the fingertip are the preferred location because they contain fewer nerve endings than the sensitive pads, which helps minimize discomfort. Individuals should rotate among different fingers and different sides of each finger to prevent the development of calluses or chronic soreness. Washing hands thoroughly with warm, soapy water and drying them completely before testing is important to remove contaminants and stimulate blood flow.
To prepare the site, gently massaging the finger from the palm toward the tip can increase capillary blood circulation, making it easier to obtain a sample. The lancing device is then pressed firmly against the selected spot on the side of the fingertip. Holding the device firmly against the skin ensures a controlled puncture. Pressing the release button triggers the spring-loaded mechanism, causing the lancet to quickly pierce and retract from the skin.
After the puncture, the device is immediately removed from the finger. If a blood drop does not form immediately, gently “milking” or massaging the finger from the base toward the puncture site will help form the sample. Avoid forcefully squeezing the area, as this can cause tissue fluid to mix with the blood, potentially diluting the sample and affecting the test result. A sufficient, round drop of blood should be collected by the test strip as quickly as possible for an accurate reading.
Safety and Troubleshooting
Safe handling and disposal of the used lancet are paramount to preventing accidental needlestick injuries and the spread of infection. After testing, the lancing device cap is removed, and the used lancet must be ejected without touching the exposed needle. Many devices include a built-in ejector mechanism, which pushes the lancet out when a button or slide is activated. Alternatively, the used needle’s protective cap, which was saved during the preparation step, can be placed on a hard surface, and the exposed tip of the lancet can be pushed into it before removal, effectively shielding the sharp point.
The used lancet must be disposed of in a designated sharps container, a puncture-proof plastic container that is clearly labeled, to protect sanitation workers and others from injury. Never discard used lancets directly into household trash or recycling bins.
Troubleshooting
If the device fails to produce an adequate blood sample, the first troubleshooting steps are to ensure the device was properly cocked and that the depth setting is appropriate for the skin thickness. If a shallow setting was used, adjusting to a higher number will increase the penetration depth and typically yield a larger blood drop.
Excessive pain may indicate that the user is consistently lancing the highly sensitive finger pad or using a depth setting that is too deep. Adjusting to a lower depth or rotating sites can help. Reusing a lancet is unsafe and should be avoided, as the needle dulls after one use, causing more pain and potential tissue damage. The exterior of the lancing device should be cleaned and disinfected according to the manufacturer’s instructions, usually at least once a week, to maintain hygiene and device functionality.