Choosing The Right Type Of Syringes

1. Insulin Syringe (Diabetic Syringe) 

One of the most common types of syringes. These are general-use, inexpensive, and disposable syringes. These are used to administer insulin in diabetic patients. They have a U-100 marking that indicates the concentration of 100 units of insulin per 1 ml and often come with a fine needle. 

2. Tuberculin Syringe (1 ml syringe with needle) 

These small syringes with needles hold up to 1 ml of fluid. These are disposable syringes with permanently attached needles. They are used for injecting subcutaneous or intradermal medicine to perform tuberculosis tests called PPD.  

3. Multi Injector Needle Syringe  

These special syringes need a refill after each injection from a built-in reservoir to give several dosages using the same syringe. These types of needles pose a risk of contamination. Hence, they are used less often.  

4. Venom Extraction Syringes 

Extract exudate from the wound without puncturing it. These syringes create a vacuum that sucks out the poison from the wound.  

5. Oral Syringe (syringe without needle) 

Oral syringes are used to measure the drug dose accurately. They are also used to administer medicines to children or animals directly into their mouths.  

6. Dental Syringe  

As the name suggests, dentists use these syringes to administer the anesthetic solution. These are also used to supply water, compressed air, or mist to the oral cavity to clean the operating area. 

7. Bulb Syringe  

 A bulb syringe removes mucus from the mouth or nose. A stuffy nose makes it hard for them to breathe. Bulb syringes are used to treat nasal congestion in babies. 

1. A barrel 

The barrel of the syringe is a transparent body used to store the fluid that is later dispensed or withdrawn. It has graduated markings to measure in milliliters or cubic centimeters. There are three main components of a syringe barrel - the outer diameter, the inner diameter, and the volume. 

• Outer diameter: The outer diameter is the thickness of the barrel. This thickness determines whether it would fit on the syringe pump. Many syringe pump manufacturers specify suitable syringe sizes for their pumps based on the volume of the syringe. 
• Inner diameter: The inner diameter is the cavity thickness, i.e., the inner part where the fluid is stored. This value helps in setting the accurate flow rate.  
• Volume: The user should carefully select a syringe that does not exceed their volume requirements. 

2. Syringe Plunger 

The plunger is a plastic or rubber cylindrical rod that fits inside the barrel. It comes with a flat or concaved end in contact with the liquid.  

Pull the plunger to fill the syringe barrel with liquid. Similarly, push it through the needle to expel the content into the body. A good seal between the plunger of the syringe and the barrel keeps everything airtight. 

3. Flange 

The flat part at the bottom of the syringe barrel, on the opposite side of the Luer lock or slip tip. It offers a place to rest the index and middle fingers while holding the syringe. 

The finger flange makes holding the syringe easier and gives the user control when injecting or withdrawing liquid. It helps ensure that medications are administered accurately and consistently. 

4. Thumb Rest  

It is a flat platform at the end of the syringe plunger. It makes it more comfortable and secure to hold while pushing the plunger during an injection. Using the thumb rest gives you better control and stability when giving medications. It helps ensure that the liquid is delivered smoothly and accurately. 

5. Rubber Stop 

The rubber stop is also called the plunger tip. It is placed at the bottom of the plunger. The flexible rubber or similar material ensures durability and resistance to chemicals. The stopper creates a tight seal with the inner cavity of the barrel. It prevents air and liquid from leaking out when the syringe is used. 

6. Syringe Needle  

It is a sharp, stainless-steel tube that is hollow and penetrates the skin, muscle, or blood vessel to deliver the contents from the syringe. It comes in various lengths and diameters. Thin needles are for subcutaneous injections. Similarly, the thicker ones are for intramuscular injections (IM injections). 

Needle Length: A needle gauge is the diameter of the needle. It is a numerical value denoted by (G). The gauge number is the size needle bore. The higher the gauge number, the smaller the needle diameter. Similarly, the lower the gauge number, the larger the needle diameter. Thus, a 30G needle will be thinner than a 22G needle. Choosing the needle size will depend on the application of the syringe. For instance, the needle gauge for IM injection would be 22-25 gauge. 

7. Needle Hub 

The needle hub is the part that joins the needle to the syringe barrel. It is either made of plastic or metal. Its purpose is to connect the needle to the syringe securely and tightly so there are no leaks during injection or withdrawal. 

The hub is often colored in a specific way that corresponds to the size of the needle. This color coding helps identify the needle size quickly. 

8. Bevel 

The bevel is the angled and sharp edge at the tip of the needle that helps penetrate the skin, muscle, or blood vessel. The design aims to minimize pain and tissue damage when giving an injection. Different needles can have various bevel styles, like short, long, or scalpel, each intended for specific uses or groups of patients. 

How the bevel is positioned during an injection can also affect the patient's discomfort. The bevel-up approach causes the least pain. Hence it is the most common way to use it. 

9. Needle Cap 

A little cover goes over the needle when the syringe is not used. It serves various purposes, such as - 

• Keeps the needle clean and sterile. 
• Helps prevent accidental needle pricks. 
• Protects the needle from any potential damage. 

10. Needle Tip 

The tip of the needle is called a Luer lock or slip tip. It is the end part of the barrel and connects the needle hub to the syringe. 

A Luer lock syringe uses fine threads to connect the needle to the syringe tightly. In contrast, the slip-tip syringe uses friction to hold the needle in place. The choice of needle tip depends on the particular use and personal preference. 

1. Leur Lock Tip  

Leur lock tip syringes have a threaded tip so the needle can twist and lock in place. It ensures a secure connection and prevents the displacement of the needle and injection from the injection site. It offers clear visual and audible confirmation of the locked position. 

2. Slip Tip  

Slip-tip syringes offer a friction-fit connection. The administrator needs to push the needle hub onto the syringe; there is no locking. These are also called Luer slip syringes. Some of them are also used for insulin or vitamin injection.  

3. Catheter Tip  

Catheter tip syringes have a tapered tip for a tight seal. They look similar to slip-tip syringes but have longer and more tapered tips. These are used to clean catheters, gastrostomy tubes, and wound irrigation.  

4. Eccentric Tip  

These syringes are commonly used while administering medication parallel to the patient's skin. They are mainly used for aspiration fluids that require closeness to the skin. These syringes are perfect for injecting into a surface vein and not penetrating both vascular walls of the vein.