What is the correct angle of entry when using a butterfly needle for blood collection?

When using a butterfly needle for blood collection, the ideal angle of entry is typically around 15 degrees. This angle allows for effective insertion into a vein without causing excess trauma to the surrounding tissue, which is crucial for minimizing discomfort for the patient and ensuring a successful draw. At this angle, the needle can easily access smaller veins, which is often the case in patients with challenging venous access.

An angle of 5 degrees is too shallow, which could lead to the needle sliding out of the vein after insertion or not entering the vein properly, making it ineffective for blood collection. Similarly, angles like 10 degrees may be slightly steeper than necessary and could risk damage to the vein wall. Angles greater than 15 degrees increase the risk of puncturing through the vein or causing hemolysis of blood cells, thereby affecting the quality of the sample collected.

Choosing the correct angle is essential for successful venipuncture, especially when a butterfly needle is used, as this type of needle is specifically designed for accessing veins that may be more difficult to draw from, such as those in pediatric or geriatric patients.