Size 22G is blue. The flow rate is 36 ml/min. These are used for kids, the elderly and people with small veins. They often used for infusions. The 20G size is pink and has a flow rate of 61 ml/min. It is the standard used for blood and infusion. Size 18G is green and has a flow rate of 90 ml/min. It is most useful for transfusions.
The 17G size is colored white with a 140 ml/min flow rate. This isn’t used often, except for patients that need plenty of IV fluids or blood transfusion.
For patients in shock, size 16G grey is used. The flow rate is 200 ml/min. It can also be used for people who have suffered trauma and bleeding. Cannula size 14G (brown, 300 ml/min flow rate) has the same application as the grey one.
The Intravenous Cannula
The intravenous cannula is used by medical personnel to access the veins of the patient, either for injecting medicine or withdrawing blood. This is commonly known as an IV. The IV cannula has a trocar on top. This is used to facilitate an opening in the body. The tube will be threaded there.
To inject the IV, a tourniquet will be set on the arms. The injection site will be cleaned after which the trocar will be injected.
The Nasal Cannula
This cannula is used to provide low level oxygen to the patient. The cannula is equipped with a tip that is placed in the nose of the patient. To secure the cannula, a flexible band is set on the head of the patient. The end of the tube is connected to the oxygen delivery apparatus.
Prior to giving a nasal cannula, the patient’s vital organs and signs are assessed. Rarely do side effects emanate from using a nasal cannula. The only complaint is usually a feeling of dryness in the nose. This happens due to the flow of oxygen and not a cause for concern. The nasal cannula is also used by people in high altitudes.
No matter what the cannula sizes or types are, they are always administered by a professional. It is particularly important for the IV cannula as side effects can come up if not used properly.