A nasal cannula is a thin, flexible tube that delivers oxygen to your nostrils. The oxygen-delivery system has four components: an oxygen source; the tube that connects to the oxygen source; two curved plastic prongs that attach to a loop at the bottom of the oxygen tubing; and a sliding plastic connector that makes the loop smaller or larger. A nasal cannula is considered a low-flow oxygen device because it can deliver 24 to 40 per cent oxygen with a flow rate of only 1 to 6 litres a minute.
Before applying a nasal cannula, start the flow of oxygen from your oxygen source. This may be a metal tank that stores compressed oxygen or an oxygen concentrator that pulls oxygen from the atmosphere and sends it through the delivery system. Adjust the oxygen source to reflect the pressure ordered by the doctor, such as 2 litres per minute. Place your fingertips over the outlet from the curved prongs of the oxygen tubing to be sure everything is working properly. When you're sure oxygen is flowing well, you're ready to apply the cannula. According to Critical Care Medicine Tutorials, a nasal cannula that's not properly positioned is useless, because it won't deliver the volume and pressure that you need. Start by gently inserting the curved prongs into your nostrils to see how they fit. If they are too long and uncomfortable, you can either ask for a different size of tubing or cut the prongs with a pair of scissors. Don't cut too much length from the prongs, or they won't stay in your nostrils. Prongs that are too short will also decrease the amount of oxygen delivered to your airways. Once the prongs are comfortably placed in your nostrils, pull a length of the looped tubing behind each of your ears to hold it in place. Leaving the loop hanging below your chin, slide the plastic connector up. This action will make the loop smaller until it rests snugly below your chin. This set-up generally stays in place even when you move. But small children or confused adults may need a piece of tape placed over the tubing on each cheek to keep it secured.
A nasal cannula can dry the nostrils and be uncomfortable around the nostrils or behind the ears. If tape is used to hold the cannula in place on the cheeks, that can also irritate the skin. Remove the cannula regularly to check for skin redness or other signs of pressure. You can gently massage areas of potential skin breakdown, apply a water-based moisturiser to limit irritation and use cotton pads to cushion the cannula behind your ears. Avoid petroleum-based ointments that can block the openings on the nasal prongs.