Humidified high flow nasal cannula (HHFNC) therapy factsheet


When babies and children are unwell, they can have difficulty breathing. 

Your child might:

  • use extra muscles to breathe
  • breathe faster than normal
  • make grunting or wheezing sounds while trying to breathe.

This is called respiratory distress. Respiratory distress can make their condition worse.

Your child may be given humidified high-flow nasal cannula (HHFNC) therapy to help them breathe in the hospital. 

HHFNC therapy helps to push pressurised and humidified air through your child’s nose to open the small parts of the lungs. This makes it easier and more comfortable for your child to breathe.

 Preparing for the treatment

Because HHFNC therapy happens in the hospital, your child will have other monitors connected to them. 

These monitors record:

  • heart rate
  • respiratory or breathing rate
  • levels of oxygen in the blood.

Your child’s treating team will talk to you about the HHFNC therapy before it starts and will answer any questions you might have.

 During the treatment

Nasal suction

Some children will need nasal suction before they start HHFNC therapy. Children and babies create a lot of mucous when sick and often cannot clear it themselves. Mucous can fill the nose and make it harder to breathe.

Your child’s nurse will place a small tube down their nasal passage to clear the mucous using suction. This should help their breathing to get better.

Nasogastric tube

Your child may also need a nasogastric (NG) tube inserted before starting HHFNC therapy. An NG tube is a small tube that goes down the nose and back of the throat to sit in the stomach.

The NG tube helps to remove any gas from the stomach that may have been swallowed during the HHFNC therapy. Removing the extra gas from the stomach will make your child more comfortable and help them breathe better.

Inserting an NG tube should not be painful, but it can be uncomfortable. Your child might cry or gag when the tube is inserted, as it can tickle the back of the throat.

Your child’s nurse will make sure the NG tube is in the right place by removing and testing a small amount of stomach acid from the tube or by taking an x-ray.

HHFNC therapy

Your child will have nasal prongs placed before the HHFNC therapy starts. Nasal prongs are the two small straw-shaped endings on a lightweight tube called a nasal cannula.

One prong is inserted into each of your child's nostrils, and the pressurised, humidified oxygen is pushed through to help them breathe. 

The nasal prongs can move, so it is important to check they are in place and working. You can gently push them back into your child's nostrils or speak to your child's treating team for help.

 After the treatment

When your child’s breathing gets better, the HHFNC therapy will need to be slowly turned down before stopping. If HHFNC therapy is stopped too quickly, there is a risk of making their breathing issue worse.

Your child will need to stay in the hospital while they are having HHFNC therapy. 

Your child’s treating team will discuss with you how long the HHFNC therapy will go for, the plan for slowly stopping HHFNC therapy, and what happens after stopping.


Eating and drinking during therapy

Always check with your child’s treating team before giving your child any food or liquids. 

Some children may be given fluids through the NG tube or an intravenous cannula in their arm.  This is to make sure they stay hydrated.

Comforting your child during therapy

HHFNC therapy can be unsettling and uncomfortable for your child. 

The prongs must stay in your child's nose, even if they are unsettled. This is so the oxygen can be pushed through properly.

For smaller babies, using a swaddle to make them comfortable and calm can be helpful. 

For older children, you may be able to hold them depending on their condition, or bring a favourite book, toy, or game to distract them. 

Once your child settles, their breathing should improve.

Last updated Tuesday 12th December 2023


This factsheet is provided for general information only. It does not constitute health advice and should not be used to diagnose or treat any health condition.

Please consult with your doctor or other health professional to make sure this information is right for you and/or your child.

The Sydney Children’s Hospitals Network does not accept responsibility for inaccuracies or omissions, the interpretation of the information, or for success or appropriateness of any treatment described in the factsheet.

© Sydney Children’s Hospitals Network 2024