A lancet is a small, single-use medical needle designed for capillary blood sampling, most often for monitoring blood glucose levels. While a lancing device provides a fast, controlled, and minimally painful skin prick, manual use may be necessary if the device malfunctions, is lost, or is unavailable. This procedure should only be considered a temporary measure in emergency scenarios and requires careful attention to technique.
Essential Preparation and Site Selection
The first step for any blood draw is ensuring infection control and adequate blood flow. Wash your hands thoroughly with warm water and soap, as this promotes circulation and removes contaminants more effectively than an alcohol wipe alone. Dry your hands completely afterward, as residual moisture can affect the accuracy of the blood sample.
To increase blood flow to the fingertips, rub your hands together vigorously or briefly soak them in warm water. Gravity can also assist; try letting your arm hang down for approximately 30 seconds before the procedure. Proper site selection involves choosing the sides of the third or fourth finger on your non-dominant hand.
Avoid the fleshy pads, the very tip, and the center of the finger, as these areas have a higher concentration of nerve endings, making the prick more painful. The index finger and thumb are generally avoided due to thicker, more callused skin. This careful preparation ensures a less painful experience and yields a free-flowing blood sample, preventing the need for excessive squeezing that can dilute the sample with tissue fluid.
Manual Lancing: The Step-by-Step Technique
After preparation, carefully remove the protective cap from a new, sterile lancet without touching the needle tip to maintain sterility. The goal of manual lancing is to replicate the speed and depth of a lancing device to minimize pain. Ensure your hand is stable and the chosen finger is held firmly to prevent movement.
Hold the plastic body of the lancet between your thumb and forefinger, positioning the needle tip perpendicular to the side of the chosen fingertip. The puncture must be a quick, firm, and decisive motion, not a slow press, to pass through the skin quickly. Apply enough force for the needle to penetrate slightly deeper than expected from a device, relying on manual control due to the lack of spring action.
Immediately after the prick, withdraw the lancet straight out of the skin. Wipe away the first small droplet of blood with clean gauze, as this initial drop often contains excess tissue fluid that interferes with test results. Allow a second, well-formed drop of blood to appear naturally at the puncture site. If blood flow is insufficient, gently massage the finger from its base toward the tip without aggressively squeezing the immediate puncture area.
Safety Protocols and Sharps Disposal
Manual lancing introduces a higher risk of accidental injury and infection because the lancet is handled directly, making strict safety protocols mandatory. A lancet is a single-use tool, and reuse is strictly prohibited, even by the same person. Reuse dulls the tip instantly and harbors bacteria, increasing the risk of infection and tissue damage.
Once the blood sample is collected, the used lancet must be immediately placed into a designated sharps container to prevent accidental needlesticks.
Improvised Sharps Containers
If a commercial sharps container is unavailable, a heavy-duty, puncture-proof plastic container with a secure, tight-fitting lid can serve as an improvised alternative (e.g., a laundry detergent bottle). This container must be opaque and clearly labeled as “SHARPS – DO NOT RECYCLE.” Seal the container with duct tape once it is no more than three-quarters full. Do not use clear plastic bottles, glass containers, or milk jugs, as they do not offer adequate protection against puncture or shattering.
After disposal, monitor the puncture site for signs of infection, such as increasing redness, swelling, warmth, or persistent pain. If these symptoms develop, or if the skin was significantly damaged during the manual procedure, prompt medical attention is necessary.