Final answer:
The butterfly infusion set is not typically used for obese patients because their veins might be deeper in the tissue, requiring a longer and larger needle for effective venous access. It is, however, often used for infants, adults with small wrists, and the elderly.
Step-by-step explanation:
The butterfly infusion set is a medical instrument designed for facilitating venous access and administering intravenous therapy. It is particularly useful for patients with delicate or difficult-to-access veins due to its small needle and flexible wings, which help stabilize the needle during insertion and infusion. Butterfly needles are commonly used for infants, the elderly, and adults with small wrists because they require a more delicate approach for venipuncture.
However, they are typically not the first choice for obese patients, primarily because their veins may be deeper within the tissue and require a longer and larger needle for successful venous access. In such cases, a standard hypodermic needle or other specialized equipment may be used to accommodate the greater tissue depth and ensure reliable intravenous access.