Hypodermic Needle

Hypodermic Needle

A hypodermic needle, commonly utilized alongside a syringe, serves the purpose of injecting substances into the body or extracting fluids from it. It may also be employed for the collection of liquid samples, such as drawing blood during venipuncture from a vein.

The application of large bore hypodermic needles proves particularly beneficial in cases of severe blood loss or shock, where swift intervention is crucial.

These needles facilitate the rapid delivery of liquids, especially when the substance cannot be ingested, either due to absorption limitations (as with insulin) or potential liver harm. The injection can be administered through various routes, depending on the medical requirements.

Typically crafted from stainless steel, hypodermic needles are formed via a process known as tube drawing, wherein the stainless-steel tube is gradually reduced in size through dies to shape the needle. The tip is beveled to create a sharp point, allowing easy penetration of the skin.

The needle gauge indicates its diameter, with various lengths available for each gauge. Gauging systems like the Stubs Needle Gauge and the French Catheter Scale are commonly used. Needles range in gauge from 7 (the largest) to 33 (the smallest) on the Stubs scale. For instance, 21-gauge needles are often employed for blood drawing, while 16- or 17-gauge needles are preferred for blood donation as they accommodate the passage of red blood cells without rupturing them.

While reusable needles are still utilized in certain scientific contexts, disposable needles are prevalent in medical practice. They feature a plastic or aluminum hub that connects to the syringe barrel via a press-fit or twist-on fitting, commonly referred to as "Luer Lock" connections.

Although primarily administered by medical professionals like physicians, nurses, and paramedics, hypodermic needles are occasionally self-administered by patients. This is notably observed in type one diabetics requiring multiple insulin injections daily or individuals with severe allergies carrying injectable medications for first aid during allergic reactions. Additionally, patients with multiple sclerosis may self-administer injections of various therapies designed for subcutaneous or intramuscular use.