Nasal Prongs
Nasal prongs, also called a nasal cannula, are one of the most widely used devices for delivering oxygen to newborns, infants, and children. This guide covers everything about them in simple, easy-to-understand language.
What Are Nasal Prongs?
Nasal prongs are a lightweight, flexible tube with two small curved tips that sit gently inside the nostrils. They are connected at the other end to an oxygen source such as a wall oxygen supply, an oxygen cylinder, or an oxygen concentrator. Oxygen or a mixture of oxygen and air flows through the tube and enters the airways through the nose.
The device was first patented in 1949 and has since become a standard tool in hospitals, emergency rooms, neonatal intensive care units (NICUs), pediatric wards, and home settings worldwide. They are preferred over many other devices because they are simple, comfortable, and allow the child to breathe, feed, and speak normally during use.
Purpose and Where They Are Used
The primary purpose of nasal prongs is to deliver supplemental oxygen when a child is not getting enough oxygen from normal breathing. The medical term for low oxygen in the blood is hypoxemia, and oxygen saturation (SpO2) is measured using a pulse oximeter. In children, oxygen therapy through nasal prongs is typically started when SpO2 falls below 92% in room air.
Common Conditions Where Nasal Prongs Are Used
- Bronchiolitis (lung infection common in infants)
- Pneumonia
- Asthma attacks
- Neonatal respiratory distress (breathing difficulty in newborns)
- Transient tachypnea of the newborn (fast breathing after birth)
- Premature birth (lungs not fully developed)
- Post-operative recovery
- Croup
- Sepsis with low oxygen levels
- Home oxygen therapy for chronic lung conditions
Where Are They Used?
- Neonatal Intensive Care Units (NICU)
- Pediatric Intensive Care Units (PICU)
- Emergency departments
- General pediatric wards
- Ambulances and transport
- Home care settings
Key advantage: Nasal prongs allow feeding, talking, and movement without removing the device, making them well-suited for infants and young children who breathe primarily through their nose.
Types of Nasal Prongs
Nasal prongs are broadly divided into two categories based on the flow rate of oxygen delivered: low-flow and high-flow. Each has specific uses and settings.
1. Standard Low-Flow Nasal Cannula (Nasal Prongs)
This is the most common type. It delivers oxygen at flow rates up to 4 litres per minute (LPM) in children and less than 1 LPM in newborns and infants. The prongs are small, soft, and sit loosely inside the nostrils. Because the flow is lower than the child's own breathing rate, some room air is also inhaled alongside the oxygen, making it less precise but comfortable for most situations.
2. High-Flow Nasal Cannula (HFNC)
HFNC delivers oxygen or a mixture of oxygen and air at much higher flow rates (2 to 60 LPM depending on size and age) that match or exceed the child's own inspiratory demand. The gas is heated to body temperature (37 degrees Celsius) and humidified to near 100% to prevent drying of the airways. The prongs used for HFNC are wider but soft, and they sit in the nostrils without blocking them fully, allowing some gas to escape (leak) intentionally to prevent pressure build-up. HFNC also creates a small amount of positive pressure in the upper airway that helps reduce the effort of breathing.
3. Neonatal CPAP Nasal Prongs
Used specifically in preterm and sick newborns, these prongs are part of a Continuous Positive Airway Pressure (CPAP) system. CPAP prongs are slightly wider than standard ones and fit more securely in the nostrils to deliver a continuous pressure that keeps the tiny air sacs of the lungs open. These are different from regular nasal cannulas and require specific CPAP equipment.
| Type | Flow Rate | Main Use | Humidification Needed |
|---|---|---|---|
| Low-Flow Nasal Prongs | Up to 4 LPM (children); less than 1 LPM (infants) | Mild to moderate hypoxemia | Not always required at low flows |
| High-Flow Nasal Cannula (HFNC) | 2 to 60 LPM | Moderate to severe respiratory distress | Yes, mandatory |
| CPAP Nasal Prongs | Varies by CPAP device | Preterm newborns, RDS | Yes, mandatory |
Sizing of Nasal Prongs
Nasal prongs come in different sizes to suit different ages and body sizes. Choosing the correct size is important for both comfort and effectiveness.
| Age / Weight | Prong Size | Notes |
|---|---|---|
| Premature newborn | Preemie / Neonatal | Very soft, smallest tip diameter |
| Newborn to 3 months | Neonatal | Curved prongs pointing toward sinuses |
| Infant (up to 10 kg) | Infant | Fits most babies under 6 to 9 months |
| Child (10 to 20 kg) | Pediatric | Prong width should be about half the nostril diameter |
| Older child (over 20 kg) | Small Adult or Adult | Check comfort and fit carefully |
Sizing tip: For HFNC, the prong diameter should occupy about 50% of the nostril opening. This ensures adequate flow delivery while allowing intentional gas leakage around the prongs, which prevents dangerously high pressure from building up in the lungs.
How to Use Nasal Prongs: Step-by-Step
The steps below apply to standard low-flow nasal prongs. High-flow systems require additional equipment setup (heated humidifier, blender, and HFNC device) and are usually set up by trained medical staff in clinical settings.
What Is Needed
- Nasal cannula of the correct size
- Oxygen source (cylinder, concentrator, or wall supply) with a flowmeter
- Connecting tubing
- Pulse oximeter (to monitor oxygen saturation)
- Hydrogel or foam dressings (optional, to protect skin under the tubing)
Step-by-Step Placement
For infants: Nasal prongs can be kept on during breastfeeding or bottle feeding. If the infant is a mouth breather or has severe nasal congestion, the effectiveness of nasal prongs may be reduced, and the medical team should be informed.
Flow Rate Reference for Low-Flow Nasal Prongs
| Age Group | Typical Flow Range | Notes |
|---|---|---|
| Preterm newborn | 0.1 to 0.5 LPM | Start at lowest effective rate |
| Newborn to 1 month | 0.1 to 1 LPM | Low flow only; always humidify |
| Infant (1 to 12 months) | 0.25 to 2 LPM | Titrate to SpO2 target |
| Toddler (1 to 3 years) | 0.5 to 3 LPM | Based on clinical response |
| Child (over 3 years) | 1 to 4 LPM | Above 4 LPM, consider switching device |
Precautions and Possible Dangers
Nasal prongs are generally very safe, but like any medical device, correct use and close monitoring are essential to avoid complications.
Nasal and Skin Complications
- Nasal skin injury: Pressure from the prongs on the soft tissue of the nostrils can cause redness, sores, or tissue breakdown, especially in preterm infants and with prolonged use. This is one of the most common complications in NICU settings.
- Nasal mucosa dryness: Dry oxygen (without humidification) can dry out the inner lining of the nose, causing discomfort, crusting, or nosebleeds (epistaxis). Humidification reduces this risk significantly.
- Pressure marks around the ears: Tubing looped over the ears for a long time can cause skin irritation. Foam pads or ear protectors can prevent this.
Oxygen-Related Risks
Oxygen toxicity: Giving too much oxygen for too long can damage the lungs and, in preterm infants, can harm the eyes (retinopathy of prematurity). Oxygen must always be titrated to the prescribed saturation target and never given unnecessarily at high concentrations.
- Incorrect flow rate: Too little oxygen may not improve the child's condition. Too much may suppress the drive to breathe in certain situations or cause lung injury over time.
- Displacement of prongs: If the prongs slip out, no oxygen is being delivered. The device must be checked frequently, especially in active infants and children.
Airway and Breathing
- Nasal blockage: If the nostrils are fully blocked with mucus, nasal prongs cannot deliver oxygen effectively. Gentle nasal suctioning may be needed first.
- Gastric distension: At higher flow rates (especially in small infants), some air may enter the stomach through the throat, causing abdominal bloating. If severe, this may worsen breathing by pushing up against the lungs.
- HFNC overpressure: Using prongs that are too large (blocking the nostril completely) with high-flow systems can cause unintended high pressure inside the lungs. Always ensure the prong diameter is about half of the nostril opening.
Equipment Risks
- Fire hazard: Oxygen increases the risk of fire. Keep the oxygen source away from open flames, smoking, electrical sparks, and flammable materials at all times.
- Kinked or blocked tubing: A kink in the connecting tube stops oxygen flow. Check the tubing regularly for bends or obstructions.
- Contamination: Reusing prongs or not cleaning them properly can introduce bacteria into the nose. Use a new cannula as per institutional or manufacturer guidelines.
Important: Nasal prongs should never be used as a substitute for more advanced respiratory support when the child's condition requires it. If breathing does not improve or worsens despite oxygen therapy, escalate to appropriate medical support immediately.
Frequently Asked Questions (FAQ)
Yes. Nasal prongs do not cover the mouth, so feeding can continue normally during use. This is one of the main advantages over face masks.
For standard low-flow nasal prongs, the flow should generally not exceed 4 LPM in children and 1 LPM in young infants. Above these rates, a different delivery device such as a face mask or HFNC system should be considered for more effective and comfortable oxygen delivery.
Regular nasal prongs only deliver oxygen. Nasal CPAP uses wider, snugly fitting prongs connected to a CPAP machine that also delivers continuous positive pressure to keep the small air sacs of the lungs open. CPAP is used for more severe breathing difficulties, particularly in preterm newborns.
Yes, especially for prolonged use. Dry oxygen can damage the delicate inner lining of a newborn's nose. Humidification is strongly recommended for neonates and for any child requiring oxygen for more than a few hours. It is mandatory with HFNC.
Skin marks occur due to prolonged pressure of the prong tips against the soft nasal tissue, especially in preterm infants with delicate skin. Using the correct size, applying thin protective hydrocolloid or foam dressings under the tubing, and checking the skin regularly help prevent this.
Yes. For children on home oxygen therapy (such as those with chronic lung disease of prematurity or other long-term conditions), nasal prongs connected to a home oxygen concentrator are commonly used. The flow rate and duration must always be prescribed and supervised by a doctor.
Use medical-grade adhesive tape or soft foam fixation pads to secure the tubing to the cheeks. For very young infants and active children, specially designed anchor systems are available. Ensure the tubing is not too tight over the ears, which can cause the cannula to shift position.
In hospital settings, follow the infection control policy, which typically involves changing the cannula every 24 to 72 hours or if visibly soiled. For home use, replace the cannula every 2 to 4 weeks under normal circumstances, and sooner during illness or infection.
Low-flow nasal prongs deliver oxygen at up to 4 LPM in children and cannot match the child's full breathing demand, so some room air is also breathed in. High-flow nasal cannula (HFNC) delivers heated and humidified oxygen at flows that meet or exceed the child's breathing demand, providing more controlled and higher oxygen concentrations and a small amount of airway pressure support.
Yes, nasal prongs can be worn during sleep. They should be secured properly to reduce displacement during movement. Monitoring oxygen saturation continuously or at regular intervals during sleep is important, especially in infants.
How to Keep the Device Clean and Safe
Daily Care
- Wipe the prongs and the section of tubing close to the face daily with a clean, damp cloth to remove any moisture, mucus, or facial oils.
- Check the tubing for kinks, cracks, or blockages every time the device is used.
- Inspect the skin around the nostrils and ears for any pressure marks or redness.
Weekly Cleaning (for devices used over multiple days, e.g., home care)
- Disconnect the prongs and tubing from the oxygen source.
- Wash the prongs in warm water with a mild, unscented soap using gentle finger pressure. Let water flow through the tubing to flush out any buildup.
- Rinse thoroughly under running water until all soap is gone.
- Shake off excess water and air-dry completely on a clean towel in a well-ventilated area, away from direct sunlight.
- Do not use cloth towels to dry the inside of the tubing as lint may be left behind.
- Reassemble only when completely dry.
- For infants or immunocompromised children, a diluted solution of 1 part 3% hydrogen peroxide with 2 parts water can be used to soak the prongs for 10 minutes, followed by thorough rinsing. Always check with the medical team before using this method.
What to Avoid
- Do not submerge the oxygen tubing in water as moisture inside can promote mold growth.
- Do not use bleach or harsh chemical disinfectants as they can degrade the plastic and irritate the skin.
- Do not share nasal prongs between children.
- Do not use the prongs if they are discoloured, cracked, stiff, or have a strong odour.
Storage
- Store clean, dry prongs and tubing in a sealed, clean plastic bag or container away from dust.
- Keep away from heat sources and direct sunlight, which can degrade the plastic over time.
- Store spare cannulas in their original packaging until needed.
When to Replace
- Replace immediately if cracked, kinked, stiff, or soiled.
- Replace during or after a respiratory illness without waiting for the scheduled change.
- In home care, routine replacement every 2 to 4 weeks is recommended even if the device looks clean.
Additional Information Worth Knowing
Monitoring During Use
Oxygen therapy is not a set-and-forget treatment. The SpO2 target must be set by the treating doctor based on the child's diagnosis. For most children, the general target is 94% to 98%. For specific conditions (such as certain heart conditions or premature newborns), the target may be different. Pulse oximetry should be used to guide therapy and avoid both under-treatment and over-treatment.
When Nasal Prongs Are Not Enough
If a child remains with low oxygen saturations despite nasal prongs at appropriate flow rates, or shows signs of worsening breathing (very fast breathing, skin sucking in between the ribs, pale or blue lips, or reduced consciousness), the child needs urgent medical evaluation for a more advanced form of respiratory support such as a face mask, HFNC, CPAP, or mechanical ventilation.
Fire Safety With Oxygen
Oxygen itself does not burn, but it makes other materials burn faster and more intensely. While a child is on oxygen therapy:
- Keep all open flames, candles, and smoking strictly away from the room where oxygen is in use.
- Do not use aerosol sprays or flammable substances near the oxygen source.
- Avoid electrical devices that spark near the oxygen equipment.
- Follow the safety guidelines provided by the oxygen equipment supplier or hospital.
Humidification
Cold, dry oxygen can irritate and dry out the lining of the nose and airways. For any child receiving oxygen for more than a few hours, humidification of the delivered gas is recommended. Humidifiers attach between the oxygen source and the cannula and pass the gas through sterile water before it reaches the patient. For HFNC, active heating and humidification is always required as part of the system.
Nasal Prongs vs Face Mask: A Quick Comparison
| Feature | Nasal Prongs | Face Mask |
|---|---|---|
| Comfort | Higher (less confining) | Lower (covers face) |
| Feeding during use | Yes | No (must be removed) |
| Max oxygen delivery | Lower with standard prongs (up to ~44% FiO2 at 4 LPM) | Higher (up to 60% with simple mask) |
| CO2 rebreathing risk | Very low | Possible with simple masks at low flows |
| Suitable for infants | Yes | Limited (size, compliance) |
Suggested References for Further Reading
- Nelson Textbook of Pediatrics (Kliegman et al.) - Chapter on Respiratory Disorders
- World Health Organization (WHO) guidelines on oxygen therapy in children: who.int
- American Academy of Pediatrics (AAP) clinical resources: aap.org
- American Association for Respiratory Care (AARC) Clinical Practice Guidelines: aarc.org
- British Thoracic Society guidelines on oxygen use in children: brit-thoracic.org.uk
- Cloherty and Stark's Manual of Neonatal Care - Chapter on Respiratory Management
Labels: Respiratory-System