IV therapy, which involves administering fluids, vitamins, nutrients, and medications directly into the bloodstream, is a prominent and valuable medical technique. However, giving IV therapy is often more complex than it sounds. In particular, IV therapy is administered with different IV needles sizes, with which every medical practitioner must be familiar.
IV needle sizes are essential in IV therapy and influence in which situations particular needles are used, who uses them, and what type of fluids they transport into the body.
If you are ready to learn everything about IV needles and their size, you are at the right place. Let’s begin by helping you differentiate the sizes before assisting you in successfully choosing a suitable IV needle!
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Different IV Needle Sizes
Medical facilities have IV therapy protocols, and certain aspects, such as the IV needles sizes, are standardized. This indicates that such standardized IV needle sizes are also used for mobile IV therapy. Every mobile infusion nurse is aware when choosing and inserting the proper IV needle size and administering IV therapy to a patient.
When it comes to needle sizes, different types of IV needles are sized by gauges, and the connection between the needle’s size and gauge is inverted. To clarify, the smaller the gauge number, the bigger the needle.
Essentially, IV needle gauge sizes range from 14 to 26 gauges. The different needles sizes are also separated by colors to distinguish them better.
| Gauge Size (Color) | Width | Length | Flow Rate | Description |
|---|---|---|---|---|
| 14 gauges (orange) | 2.1 mm | 45 mm | 240 ml/per minute | Mostly used during surgeries and rapid blood transfusions |
| 16 gauges (gray) | 1.8 mm | 45 mm | 180 ml/min | Utilized during surgeries; can quickly deliver fluids or blood to the patients |
| 18 gauges (green) | 1.3 mm | 32 mm | 90 ml/min | Used when patients are severely dehydrated or have lost blood; utilized during CT PE protocols and other imaging tests |
| 20 gauges (pink) | 1.1 mm | 32 mm | 60 ml/min | Most common IV needles sizes for general infusions |
| 22 gauges (blue) | 0.9 mm | 25 mm | 36 ml/min | Excellent for administering general infusion therapy but often too narrow for blood transfusions; used when treating children and elders or when patients don’t need a lot of fluids during their IV therapy |
| 24 gauges (yellow) | 0.7 mm | 19 mm | 20 ml/min | Used when a child or infant needs either a blood transfusion or an infusion |
| 26 gauges (purple) | 0.6 mm | 19 mm | 13 ml/min | Only used in children and infants because they are too tiny to transfer an IV therapy to an adult’s vein |
Factors to Consider When Selecting IV Needles Sizes
Selecting suitable IV needles sizes is vital because distinctive IV therapies can be done only with a particularly sized needle. That means that when picking the IV needle size, you have to pay attention to factors such as:
Type of therapy
Type of solution
Infusion rate
Duration of IV treatment
Vessel size and depth
Patient’s age and condition
Diagnosis
Bigger gauge IV needles are used when administering a smaller amount of medication into a patient’s vein and are commonly used in pediatrics. They are fit for thin fluids, which can quickly pass through their narrow diameter.
In contrast, smaller gauge needles can deliver larger quantities of medications, fluids, and blood. They are the proper selection when administering thick fluids, usually to adults needing IV therapy in a single dose.
Choosing the Right Size of IV Needle
To choose the right size of an IV needle, you must know which type of IV therapy your patient needs. As noted above, the patient’s age and medical condition must also be regarded.
For example, large gauge sizes such as the 14, 16, and 18 gauge are best for patients with severe trauma who need a large volume of IV therapy, which must be pushed at a rapid flow rate. Likewise, during surgeries, anesthesiologist nurses often use 18-gauge needles.
Conversely, small gauge sizes such as the 20 gauge are the right pick for continuous IV therapy infusions and are commonly used in adults.
Finally, the smallest gauges, the 22, 24, and 26, are utilized for intermittent general infusions in children and older adults. They are also the proper pick for patients with fragile veins needing continuous IV therapy.
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Tips for Successful IV Needle Insertion
Putting patients at ease
The first thing to do when giving IV therapy to a patient is to put the patient at ease.
By instructing the patient to lie down before administering the IV therapy, they can relax and enable better blood flow to their veins. Moreover, the patient’s arm must be laid flat, and it must be straight and stabilized.
If the arm can’t be straight when lying on the bed, an extra pillow or blanket is used to find the best position and angle for inserting the IV needle.
Additionally, the patient doesn’t need to watch when the insertion is done because strains retract the arm and make the insertion difficult, or the patient might become scared and move, resulting in a missed vein.
Site selection
The site of the venipuncture is of significant importance. To find the proper site for needle insertion, it’s advised to always start from the lowest veins available and go upward. This means starting with the distal veins; if you don’t find an appropriate vein, you can go upward and check the other available veins.
When a proper venipuncture site is found, the next step is to place the tourniquet correctly. The tourniquet should be applied around 3-4 inches above the chosen venipuncture site.
Assessing the vein
Depending on the patient, finding the ideal vein for insertion may take time. Everybody is different, and expectedly, patients will have distinct veins.
Well-hydrated people usually have firm and easy-to-assess veins. In contrast, dehydrated patients’ veins can be weak and challenging to assess.
When you have spotted a good vein with your eyes, it’s best to feel it with your hands, too. Palpitating the vein can tell you whether it’s in a condition to accept the IV needle or if it will blow after insertion.
Moreover, the IV needles sizes play a great role when evaluating the vein. In other words, the needle size and the cannula gauge must match the vein size. If a vein is smaller than a needle, it will blow and injure the patient.
Making the vein visible
When a venipuncture site is found, and the vein is assessed, the next step is to make the vein visible.
A warm compress on the site is one of the best tips for making veins visible and dilated. The warm compress is used for 15 minutes before inserting the IV needle.
Similarly, if the patient has smaller veins, applying nitroglycerin on the venipuncture site can help. The ointment can be left for 2-3 minutes before being rubbed off with alcohol.
When rubbing alcohol, it should always be rubbed in the direction of the venous flow to improve the filling of the vein and push the blood past the valves.
Finally, a vein locator is used for veins that are very difficult to find. Transilluminator lights and ultrasound machines can illuminate the vein pathways and give visual direction.
Inserting the IV catheter right
Before inserting the needle, the rubbed alcohol must be dry. The IV needle, after the alcohol has dried, must be inserted atop the vein.
To correctly insert the IV needle, hold the catheter at a 15-30 degree angle over the patient’s skin and then advance the needle forward. It’s best to stop when there’s resistance because the vein might be disrupted and injured.
On the other hand, if there’s a steady backflow of blood into the flashback chamber and blood oozes into the catheter, the insertion is successful. Then, the catheter can be secured and the infusion line opened.
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Conclusion
All the different types of IV needles sizes above are standardized and widely employed in the healthcare industry. Therefore, they are separated with colors and gauges and selected according to the needle length, width, and flow rate.
Every medical practitioner must know the different types of needles used for IV therapy because making a mistake and inserting an unsuitable needle can result in an injury and complicate the patient’s condition.
If the proper IV needle sizes are used as instructed, IV therapy can become a straightforward procedure every nurse can do with ease.
