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What is a cannula?
A cannula is a tiny tube that medical professionals place into a patient’s vein or bodily cavity, such as the nose. The cannula is used by doctors to drain fluid, give medication, or deliver oxygen. Blood samples from the body are also taken using a cannula.
How does a cannula work?
Typically, the term cannula refers to a tiny plastic tube that is placed into a bodily cavity using a needle to puncture a vein or blood vessel. The cannula is then left in place for simple access to withdraw or inject anything into the vessel after the needle has been taken out.
Side read: What are neutrophils in a blood test?
Cannula types
The technique and the patient’s level of comfort determine the cannula type to be used. There are two main types of cannula:
IV cannula
IV cannulas are small, flexible tubes that medical professionals insert into veins to administer various treatments and preventative care. Medical professionals can use the cannula to directly inject drugs, fluids, or blood after it has been put into the vein.
There are three basic IV cannula types described below:
Peripheral IV cannula: The peripheral IV cannula is the most widely used IV cannula. It is typically used for surgery and emergency room patients, as well as for people who receive radiological imaging.
These IV lines are only utilized for a total of four days at a time. It’s glued to the skin using adhesive tape or a non-allergic substitute after being connected to an IV catheter.
Central line IV cannula: For patients undergoing lengthy therapies who need to receive medication or fluids over several weeks or months, this type of IV cannula is used.
They aid with the quicker delivery of medications for prompt responses. Additionally, they work well for introducing significant doses of blood or any other fluid into the patient’s body.
This IV cannula is put into the femoral vein, subclavian vein, or the neck’s jugular vein.
Midline catheter: For individuals receiving treatment that lasts more than five days but less than a month, the midline catheter cannula type is the ideal option.
They are frequently used to extract blood samples or administer substances because they are thought to as a less invasive technique.
Nasal cannulas
Nasal cannulas are made of flexible tubing that fits within the nostrils to distribute oxygen.
Standard nasal cannulas have a lesser oxygen flow than other types, such as high-flow nasal cannulas (HFNC). HFNCs may also warm the gas to 98.6 F. Warmer, more humid air can facilitate easy breathing whereas colder, dryer air can cause airway inflammation.
Because it is lighter, more comfortable, and less irritating to their airways than a typical nasal cannula, some patients prefer the HFNC.
Sizes and flow rates of the cannula
In a clinical context, various cannula types and sizes are available. They come in a variety of colors, sizes, and most importantly, uses.
It’s important to remember that the cannula number decreases as the cannula size increases. For instance, a cannula with a diameter of 16G will flow more quickly than one with a diameter of 22G.
“Birmingham gauge” is what the “G” in cannula size stands for. This gauge is used to display the thickness or diameter of various hypodermic needles.
Now, let us see cannula types and their sizes with flow rate and uses.
IV cannulas – Types of cannulas and their sizes
IV cannulas come in various diameters, and their purpose is indicated by the color they are assigned. In general, IV cannula sizes range from 14 to 24 gauge. The patient’s condition, the IV cannula’s intended use, and the urgency of the fluid delivery are taken into consideration while determining the size.
Different cannula sizes with their flow rates, color, and uses are described below:
1- Cannula size 14G
- Color: Orange
- Flow rate: 10.3l/hr for blood, 16.2l/hr for plasma, and 13.5l/hr for crystalloids
- Uses: Fluid replacement, surgeries, blood transfusion, and trauma cases
2- Cannula Size 16G
- Color: Grey
- Flow rate: 7.1L/hr for blood, 10.8l/hr for plasma, and 9.4l/hr for crystalloids
- Uses: IV fluid replacement, surgeries (where instant results are required), blood transfusion
3- Cannula size 18G
- Color: Green
- Flow rate: 2.7l/hr for blood, 4.8l/hr for plasma, and 4.1l/hr for crystalloids
- Uses: Trauma cases, blood transfusions, large fluid volume, major surgeries, stem cell harvestings, fluid replacement, and parenteral nutrition
4- Cannula size 20G – Mostly used cannula type in clinical settings
- Color: Pink
- Flow rate: 1.9l/hr for blood, 3.2l/hr for plasma, and 2.9l/hr for crystalloids
- Uses: Blood and IV fluids transfusions
5- Cannula size 22G
- Color: Blue
- Flow rate: 1.1l/hr for blood, 1.9l/hr for plasma, and 1.7l/hr for crystalloid fluids
- Uses: Fluids and blood transfusions in smaller veins, for elderly, oncology, and pediatric patients
6- Cannula size 24G
- Color: Yellow
- Flow rate: 20ml/min for blood
- Uses: Used in neonates and children
IV cannula size for baby
Smaller cannulas are needed for babies; depending on where the catheter will be inserted. Usually, the cannula size for babies is 24–22 G cannulas.
IV cannula size for adults
Cannula size for adults depends on the type of use. Usually, cannula with sizes 20-15 G is used with 20 G being the most frequently used.
Nasal cannulas sizes and flow rates
Nasal cannulas come in a variety of sizes and flow rates. Nasal cannulas come in sizes for adults, children, and infants, unlike the numerical sizes of intravenous cannulas.
Regular flow nasal cannulas only deliver up to 4-6 liters of extra oxygen per minute. However, systems for high-flow nasal cannula therapy can give up to 60 liters of oxygen per minute.
Uses of cannula
The uses of cannula vary depending upon its type.
IV cannula uses
IV cannulas are frequently used for:
- Blood transfusions or draws
- Drug administration
- Fluid administration.
Nasal cannula uses
Using nasal cannulas, a person can breathe oxygen. They may be helpful if someone is having trouble breathing.
Nasal cannulas are reportedly used by medical professionals to:
- Heart failure
- Pneumonia
- Respiratory failure
- COVID-19
- Collapsed lung
- Hypoxia
- Breathing difficulties
Side read: Steam nasal therapy for COVID-19 treatment
Cannula vs. catheter
Both flexible tubes known as catheters and cannulas can be put into veins or cavities to remove or add fluid, administer medication, or draw blood. Depending on the nation or location, certain medical experts may use the terms interchangeably.
However, distinctions between the two are frequently made:
- Cannula: A cannula is often a tiny plastic tube that is introduced into a bodily cavity using a needle to rupture a vein or blood artery. The cannula is then left in place for simple access to withdraw or inject anything into the vessel after the needle has been taken out.
- Catheter: A bigger plastic tube that is put into a body cavity that already has an opening, such as the bladder or an open wound that needs help draining, is commonly referred to as a catheter.
Cannula price in Pakistan
Specification, size, and type all have an impact on cannula prices. Additionally, it depends on the brand you choose to buy. IV cannula prices typically vary from 60 to 160 PKRper piece.
Conclusion
Flexible tubes known as cannulas are affixed to a person’s body and can introduce or drain various substances.
A nasal cannula is used to administer oxygen to a patient while an IV cannula is used by a doctor or nurse to draw blood or administer medication.
IV cannulas can lessen the need for needle sticks and facilitate the administration of fluids or medications to a patient’s body. A person who has trouble breathing can benefit from nasal cannulas because they provide them access to more oxygen.
We hope this article has added greatly to your knowledge. If you want to get more information about cannula types, their sizes, and more, you can have a quick discussion with the medical specialists near you through Healthwire.
