Nasal Cannula

What Is a Nasal Cannula and How Does It Help?

If you or someone you care for has been prescribed supplemental oxygen, you have probably come across the term nasal cannula already. It is one of the most widely used oxygen delivery devices in both hospital and home settings across the UK. The Clear O2 nasal cannula is a lightweight, single-use device designed to deliver a steady, controlled flow of oxygen directly through the nostrils — making it far more comfortable for everyday use than a full face mask. Whether you are managing a long-term respiratory condition or supporting recovery at home, having the right equipment matters enormously.

Oxygen therapy is used to treat a range of conditions where blood oxygen levels fall below normal. According to the NHS, low blood oxygen — known as hypoxaemia — can occur in conditions such as chronic obstructive pulmonary disease (COPD), pneumonia, heart failure, and sleep apnoea. A nasal cannula allows patients to receive the oxygen they need while still being able to talk, eat, and move around with relative ease. You can also explore our Ear, Nose and Throat range for related respiratory support products.

How Does a Nasal Cannula Work?

The mechanism is straightforward, which is part of what makes this device so practical. Oxygen flows from a supply source — such as a concentrator or cylinder — through flexible tubing and into two small curved prongs that sit just inside the nostrils. From there, the oxygen mixes with the air you breathe in naturally, increasing the overall concentration of oxygen reaching your lungs.

• Oxygen enters via the supply tubing connected to your oxygen source
• The two nasal prongs direct flow into the nasal passages
• Oxygen mixes with ambient air during inhalation
• The increased fraction of inspired oxygen raises blood oxygen saturation
• Exhalation occurs normally — no valve or seal is required

Because the device does not seal around the face, it is classed as a low-flow, variable-performance system. The actual oxygen concentration delivered depends on the flow rate set and the patient's own breathing pattern.

Who Should Use a Nasal Cannula?

A nasal cannula is appropriate for patients who need supplemental oxygen at low to moderate flow rates — generally between 1 and 6 litres per minute. It is not suitable for patients who require high-concentration oxygen therapy, such as those in acute respiratory failure, who would typically need a non-rebreathe mask instead. Always follow the guidance of your prescribing clinician regarding flow rate and duration of use.

• Adults and children with COPD requiring long-term oxygen therapy (LTOT)
• Patients recovering from surgery or acute illness at home
• People with heart failure or pulmonary conditions causing low oxygen saturation
• Individuals using portable oxygen concentrators for ambulatory oxygen therapy

How Does a Nasal Cannula Compare to an Oxygen Mask?

Is a Nasal Cannula Safe to Store and Use at Home?

Yes — provided you follow a few important safety rules. Oxygen supports combustion, which means it can cause fires to ignite or spread more rapidly. Never use a nasal cannula near open flames, lit cigarettes, or gas cookers. Keep your oxygen equipment at least two metres away from any heat source, and store unused cannulas in their original packaging in a cool, dry place away from direct sunlight. If you are also managing other health conditions alongside your oxygen therapy, our Electrical Health and Diagnostic range includes pulse oximeters and other monitoring tools that can help you track your oxygen saturation at home.

Replace your cannula regularly — typically every two to four weeks — or sooner if it becomes discoloured, damaged, or uncomfortable. Never share a cannula with another person, as this poses an infection risk.

This product is a medicine. Speak to your doctor or pharmacist before using if you have an underlying medical condition or are taking other medicines.

What Is a Nasal Cannula and What Is It Used For?

A nasal cannula is a medical device used to deliver supplemental oxygen to patients who cannot maintain adequate blood oxygen levels through normal breathing alone. The Clear O2 nasal cannula consists of lightweight, flexible tubing with two small curved prongs that sit just inside the nostrils, connected to an oxygen supply source such as a concentrator or cylinder. It is one of the most commonly used oxygen delivery devices in the UK for both hospital and home settings.

It is used in the management of conditions including chronic obstructive pulmonary disease (COPD), heart failure, pneumonia, pulmonary fibrosis, and post-operative recovery where blood oxygen saturation falls below clinically acceptable levels. The NHS recommends that long-term oxygen therapy (LTOT) be used for at least 15 hours per day in eligible patients to achieve meaningful clinical benefit. A nasal cannula is the standard delivery method for LTOT in the home setting.

What Do You Need to Know Before Using a Nasal Cannula?

Before using this device, it is important to be aware of the following contraindications, warnings, and safety considerations:

• Do not use near open flames, lit cigarettes, gas cookers, or other ignition sources — oxygen accelerates combustion
• Do not use if the tubing or prongs are visibly damaged, cracked, or discoloured
• Do not share your cannula with another person — this poses a cross-infection risk
• Do not adjust your prescribed oxygen flow rate without consulting your doctor or respiratory nurse
• Patients with COPD should only use the flow rate prescribed — excessive oxygen in COPD can suppress the hypoxic drive to breathe
• Not suitable for patients requiring high-concentration oxygen therapy (above 44%)
• Seek medical advice before use if you are pregnant or have a condition affecting your nasal passages

There are no known drug interactions associated with this device, as it is a medical device rather than a pharmacological product. However, if you are using medications that affect your respiratory system — such as bronchodilators or sedatives — always inform your prescribing clinician, as these may influence your oxygen requirements.

• No pharmacological drug interactions identified
• Inform your clinician of all medicines you are taking, particularly respiratory or sedative drugs

How Should You Use a Nasal Cannula?

Using a nasal cannula correctly ensures you receive the right amount of oxygen and minimises discomfort. Follow these steps carefully:

1. Wash your hands thoroughly before handling the device
2. Remove the cannula from its sterile packaging
3. Connect the tubing securely to your oxygen supply source
4. Set the flow rate to the level prescribed by your doctor or respiratory nurse — do not adjust this yourself
5. Insert the two curved prongs gently into your nostrils, with the curved tips pointing downward and inward
6. Loop the tubing over each ear and slide the plastic adjuster up under your chin to secure a comfortable, snug fit
7. Check that oxygen is flowing by briefly placing your hand near the prongs
8. Use for the duration prescribed — for LTOT, this is typically at least 15 hours per day

If you are also monitoring your oxygen levels at home, you may find our Electrical Health and Diagnostic range helpful — it includes pulse oximeters suitable for home use.

What Are the Possible Side Effects of a Nasal Cannula?

As a medical device, a nasal cannula does not cause pharmacological side effects. However, physical discomfort and local irritation can occur, particularly with prolonged use. Most issues are mild and manageable.

Common side effects:

• Nasal dryness or irritation inside the nostrils
• Mild skin pressure marks or soreness around the ears from the tubing
• Dryness or soreness of the lips and mouth (particularly at higher flow rates)
• Mild headache, which may indicate the flow rate needs reviewing

Less common side effects:

• Nosebleeds (epistaxis) associated with prolonged nasal dryness
• Skin breakdown or pressure sores behind the ears with extended use
• Nasal congestion or increased mucus production

Using a humidifier attachment with your oxygen supply can significantly reduce nasal dryness. Applying a small amount of water-based moisturiser around the nostrils — never petroleum-based products near oxygen — may also help. If you experience persistent discomfort, speak to your respiratory nurse or GP.

How Should You Store a Nasal Cannula?

Proper storage keeps the device hygienic and ready for use. Follow these guidelines:

• Store in the original sealed packaging until ready to use
• Keep in a cool, dry place away from direct sunlight and heat sources
• Do not store near open flames, gas appliances, or smoking areas
• Keep out of reach of children
• Do not use after the expiry date printed on the packaging
• Dispose of used cannulas safely — do not reuse single-use devices

For patients managing multiple health conditions alongside oxygen therapy, our First Aid range includes additional home care essentials that complement your respiratory equipment.