A cannula is a flexible tube that can be inserted into the body. For medical use, there are 11 different types of cannulae. The most commonly used are the intravenous and the nasal cannulae.
An intravenous cannula is used to give medical personnel access to a patient’s vein for the withdrawal of fluid or insertion of medicine or other fluids. It is commonly called an IV. Typically, the intravenous cannula is topped with a trocar, or needle, which is used to create an opening in the body through which the tube is threaded.
To insert an IV, a medical professional will first place a tourniquet around her patient’s arm to hold blood in the arm. Once the veins in the hands and arm are full, she will clean the area around the injection site and insert the trocar into a full vein. The cannula will be pushed over the needle and into the vein before the needle is removed and the tube secured to the skin with medical tape.
There are four main complications that may arrive from the insertion of an IV. A hematoma is bruising that occurs as a result of a bad tube placement. Infiltration is what happens when the tube is inserted under the skin, but not into a vein. An embolism occurs when air travels down the tube into the vein, or if a piece of the cannula breaks off and travels down the blood stream. Phlebitis is inflammation of the vein holding the tube.
A nasal cannula is used to deliver low levels of oxygen to a patient who needs supplemental oxygen. It is fitted with a horseshoe-shaped tip on one end that is inserted into a patient’s nose, and a flexible band that is secured around a patient’s head to hold the cannula in place. The other end of the tube is attached to a tank or other type of oxygen delivery system. Before a patient is given a nasal cannula, his vital signs will be checked. He will be monitored while receiving oxygen to make sure that he is comfortable and that the oxygen levels in his body are increasing.
There are few complications and side effects associated with wearing a nasal cannula. Patients may experience some dryness in the nose as a result of the oxygen flow. Nasal cannulae are not just for patients. They are also used by aviators who need supplemental oxygen when flying in high altitudes.