What is a Nasal Cannula?
A nasal cannula is a small, lightweight device that delivers extra oxygen through your nose. It has a thin, flexible tube that rests over your ears and two short prongs that sit just inside your nostrils. The tubing connects the cannula to an oxygen source (such as a tank or concentrator) that delivers supplemental oxygen to help improve breathing. Unlike an oxygen mask, the nasal cannula does not cover your mouth, so you can talk and eat freely while you wear it. Doctors use nasal cannulas for patients who can breathe on their own but need a boost in oxygen intake. For example, those with mild to moderate low oxygen levels.
Types of Nasal Cannula
There are two main types of nasal cannulas: low-flow nasal cannulas and high-flow nasal cannulas. The primary difference is how much oxygen they can deliver and whether the system humidifies and heats the oxygen. A high-flow nasal cannula can provide a much larger volume of oxygen—up to about 60 liters per minute—and usually delivers warmed, humidified oxygen to prevent dryness. By comparison, a low-flow nasal cannula delivers oxygen at a lower rate, generally no more than 4–6 liters per minute, and does not heat or humidify the oxygen. Because the system does not humidify low-flow oxygen, it can dry out your nasal passages over time and may cause minor irritation or nosebleeds if you use it at higher rates. Your healthcare provider will determine which type and flow rate suit your needs based on how much oxygen support you require.
What is a nasal cannula used for?
A nasal cannula delivers oxygen therapy to patients who are not taking in enough oxygen on their own. Oxygen helps your organs work properly, and certain diseases or situations can lower the amount of oxygen in your blood. In these cases, the nasal cannula provides the extra oxygen your body needs to keep your levels healthy. It relieves symptoms such as shortness of breath and makes it easier to breathe.
You should only use oxygen therapy when your doctor recommends it, because using more oxygen than you need or using it when you do not need it can be harmful. Always follow the instructions your healthcare provider gives you about how much oxygen to use, and never change the flow rate of your nasal cannula without talking to a medical professional first.
When is a Nasal Cannula Used?
Doctors recommend a nasal cannula when someone needs extra oxygen because of a health condition or environmental factor. In practice, people use this device for many respiratory and cardiac conditions that lower oxygen levels. For example, you might use a nasal cannula in situations such as:
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Chronic lung diseases like asthma, bronchitis, emphysema, and COPD (Chronic Obstructive Pulmonary Disease)
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Respiratory infections such as pneumonia or severe viral pneumonia from COVID-19
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Pulmonary fibrosis or cystic fibrosis
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Cardiovascular problems, including heart failure that reduces oxygen levels
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Sleep apnea
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Recovery from a serious illness or surgery, for instance, after removal of a breathing tube (extubation) or while healing from a collapsed lung, when doctors gradually reduce higher oxygen support
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High-altitude travel, where the air is thin and travelers need help maintaining normal oxygen levels
A nasal cannula supports people of all ages, from babies whose lungs have not fully developed to older adults with chronic lung diseases. In short, if a person can breathe independently but needs a little more oxygen, a nasal cannula usually serves as the preferred option. In more severe cases of oxygen deprivation, clinicians may use other devices, such as an oxygen mask or a ventilator.
How to Use a Nasal Cannula
It is quite easy to use a nasal cannula. The device usually comes as a one-piece tube with prongs to be placed in your nostrils. You use it using the following basic steps, as recommended in a home care guide:
Step 1
Wash your hands, as this is important to prevent germs from being transmitted. Take out the nasal cannula from its package.
Step 2
Connect the end of the cannula tubing to your oxygen source; this may be an oxygen tank, concentrator, or wall outlet in a hospital. It should fit snugly.
Step 3
Setting the flow rate. The oxygen flow knob should be set to the prescribed liter flow, the amount of oxygen per minute, based on a prescription from your doctor. Common flow settings for people at home range from 1 to 5 liters per minute.
Step 4
You should feel a light flow of air on the tip of your nose or your hand to make sure oxygen is coming through the prongs.
Step 5
Position the two prongs facing up and curved slightly toward you, hold the cannula and insert the prongs into your nostrils, allowing them to rest inside your nostrils until they are comfortable.
Step 6
Pull the tubes upward to loop over both of your ears. This helps to keep the cannula in place. (Some cannulas may be designed to loop behind the head rather than over the ears, if desired.)
Step 7
On the cannula tubing, there is a small sliding adjuster- usually referred to as a bolo. Slide this up under your chin in order to tighten the fitting. It should be snug enough to hold the prongs in place but shouldn’t be uncomfortably tight.
Step 8
Leave a little slack , you should be able to fit two fingers between the tubing under your chin and your skin, so it’s not too tight. Make sure the prongs stay in your nose and the tubing isn’t pulling.
Tips to Use Nasal Cannula
After you position the nasal cannula, continue breathing normally through your nose. The oxygen mixes with the air you inhale and increases the amount of oxygen that reaches your lungs. While you use the cannula, avoid kinking or pinching the tubing, because this can cut off the flow of oxygen. Keep the oxygen source upright and secure as well. If your nose feels dry, you can use a saline nasal spray or attach a humidifier to the oxygen to add moisture. Lastly, remember that oxygen is a fire hazard: do not smoke, light candles, or use gas stoves while receiving oxygen therapy, and avoid placing the equipment near sources of heat.
If you use oxygen at home long-term, clean the cannula regularly and change it every week or two to keep it sanitary, or as your care team advises. Your care team will likely monitor your oxygen levels with a pulse oximeter to make sure the flow rate is correct and your blood oxygen stays within a safe range.
Benefits of Using a Nasal Cannula
Nasal cannula oxygen therapy has several advantages over other oxygen delivery methods. The most important advantage is that it doesn’t cover your mouth, so you can speak and eat comfortably without a problem while receiving oxygen. This definitely makes daily activities easier and improves comfort. Some of the key benefits of nasal cannula oxygen therapy include:
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Easier breathing and less shortness of breath
Extra oxygen can make you feel like you’re “not starving for air,” so breathing feels more normal. This relief can greatly improve your quality of life and ability to be active.
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Less fatigue
When you’re not struggling to breathe means your body does not have to work as hard, so you will often feel less tired during the day.
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Better sleep
Most people with chronic lung issues have poor sleep due to low oxygen at night. Oxygen through a cannula could improve sleep quality by keeping your levels steady while you rest.
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More energy for daily activities
With appropriate oxygen, you may have more stamina and energy to exercise, travel, and socialize. Essentially, proper oxygenation helps you stay more active and do the things you enjoy.
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Convenience and mobility
Nasal cannula are lightweight and portable. You have relatively free movement with a cannula, especially if connected to a portable oxygen concentrator or small tank, whereas some oxygen masks have a very bulky makeup. They also come in various lengths and sizes for infants all the way to adults.
All these benefits contribute to making oxygen therapy easier to tolerate and integrate into everyday life. Many patients feel that using a cannula gives them back a sense of normalcy because they can breathe easier and function better day-to-day.
Disadvantages and Risks of Using a Nasal Cannula
While nasal cannulas are simple and handy, there are a few disadvantages and risks involved in their use. Medical treatment with oxygen can be harmful if it is not used properly or is used for too long. The following are some of the possible disadvantages:
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Nasal dryness or irritation
The continuous flow of oxygen acts to dry the lining in your nose, causing irritation or sometimes minor nosebleeds. This is most common with the low-flow cannula on higher settings, since the oxygen isn’t humidified. For comfort, you can apply a water-based lubricant or saline nasal spray, and most high-flow systems are designed with a humidifier that adds moisture to the oxygen.
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Risk of fire
Although oxygen itself does not burn, it significantly enhances combustion. Using a nasal cannula means one has oxygen-enriched air in the surroundings, which may be highly risky if exposed to flames or sparks. You must therefore avoid smoking, open flame (candles and gas stove), and even some kinds of electric appliances or aerosol sprays while on oxygen. Oxygen equipment should also be kept away from sources of heat to avoid accidents.
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Oxygen toxicity
Too much oxygen for extended periods will damage your lungs. This might be referred to as pulmonary oxygen toxicity, a condition that can cause coughing, chest pain, or more serious lung issues. It is one of the many reasons why you will want to use the prescribed rate of oxygen flow and should not increase it yourself. More is not better, and a too high concentration of oxygen actually reduces the breathing drive over time.
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Nasal soreness or pressure ulcers
The cannula rests on your nostrils and ears, and if it’s too tight or used for a long time, it may cause skin soreness where it rubs or presses. This is usually minor and can be managed by adjusting the fit or using soft foam padding on the tubing behind the ears.
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Abdominal bloating due to swallowing air
Sometimes, especially when utilizing a high-flow nasal cannula, air may be swallowed into the stomach accidentally. This can present as abdominal distension or discomfort. Children and patients under anesthesia are more susceptible to this problem because high flow oxygen can sneak air into the digestive tract if the general airway pressure is insufficiently high to keep the majority of it in the lungs.
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Rare risk of lung injury
Though rare, there is an associated risk of developing a pneumothorax from the high levels of oxygen flow or pressure over time. This is more associated with high-flow oxygen therapy in the critical care setting. For example, one study noted that approximately 1% of children on high-flow nasal oxygen experienced a pneumothorax. While rare, this complication serves as a reminder to monitor those patients on high levels of oxygen.
Most of these risks can be mitigated through proper use and medical supervision of the device. Always use the nasal cannula as instructed, and keep in regular contact with your healthcare provider while on oxygen therapy. They will make sure that the benefits associated with oxygen use outweigh the risks in your case.
Frequently Asked Questions
Q: Is it better to use a nasal cannula or an oxygen mask?
A: That depends on the situation. Usually, an oxygen mask can provide a higher concentration and flow than a nasal cannula, which may be needed in severe cases of breathing complications. That doesn’t mean a mask is “better” for every case, though. Nasal cannulas are more comfortable and allow you to talk and eat, which is great for long-term or low-to-moderate oxygen needs. Masks might be used if you need a lot of oxygen quickly or if you breathe through your mouth. In short, it is all about your medical needs and your doctor’s recommendation.
Q: What is the correct flow for a nasal cannula?
A: The right flow rate for a nasal cannula is prescribed by your doctor based on how much oxygen you require. In general, a standard nasal cannula is utilized at flow rates from 1 to 6 liters per minute. Each liter per minute increases the FiO2 by a few percent. If you require more oxygen than a cannula can provide at 6 L/min, then a high-flow nasal cannula system can be implemented. These can deliver up to 60 L/min of warmed, humidified oxygen in the hospital environment. It’s essential to use the flow rate that’s ordered for you; if it is too low, you will not get enough oxygen benefit, and if it is too high, it could cause side effects. When unsure, always confirm with your health professional about your flow rate.
