Non-Invasive Breathing Support (NIV)

Reviewed by: HU Medical Review Board | Last reviewed: May 2023

People with spinal muscular atrophy (SMA) often have difficulty breathing because of chest muscle weakness. Breathing support can make sure they get enough oxygen to meet their body’s needs. Breathing support usually includes non-invasive ventilation.

Non-invasive ventilation (NIV) refers to breathing support given using devices on or outside the body. No devices are placed inside the body. NIV helps support breathing using a mask over the nose or over the nose and mouth. The mask is connected to a machine that controls air pressure.

How often to use non-invasive breathing support is different for every person with SMA. Talk to your doctor to determine what methods to use and when to use them.

Why is non-invasive ventilation used by people with SMA?

Chest muscle weakness can lead to breathing difficulties in SMA. Many children with SMA have under-developed lungs. This can cause shallow or slow breathing (hypoventilation) when the lungs cannot take in enough oxygen. Hypoventilation is most common during sleep because muscles naturally relax during sleep.1

Non-invasive ventilation can help prevent hypoventilation and support breathing for children with SMA. Soon after diagnosis, families should discuss non-invasive ventilation options with a pulmonologist. This is a doctor who specializes in lung care. They can help create a plan of how and when to use non-invasive ventilation methods. Children with type 1 or 2 SMA should be tested for lung function by a pulmonologist every 3 to 6 months.1

What are some types of non-invasive ventilation?

Non-invasive ventilation techniques use a machine connected to a face mask to make sure people with SMA get enough oxygen. Two commonly used ventilation techniques are bi-level positive airway pressure (BiPAP) and mechanical ventilation. Ask your pulmonologist which is best for your child.1

Bi-level positive airway pressure (BiPAP)

A BiPAP machine gives 2 levels of air pressure through a face mask or tube through the nose. The machine provides more air when children inhale and less air when children exhale. The BiPAP machine senses the child’s normal breathing cycle. It can then work at the same rate as this cycle. It will also give air if children are not breathing enough during deep sleep.1

Your pulmonologist will advise you on what settings to use, such as the air pressure and breathing rate. These settings will be personalized based on a sleep study and other breathing function tests.2

Continuous positive airway pressure (CPAP) should not be used for people with SMA. It gives 1 continuous amount of air pressure. This method may not allow breathing muscles enough rest in people with SMA.2

Mechanical ventilation

Mechanical ventilators have more options and settings than BiPAP. This allows for more control of breathing. They can be used with a face mask, whether awake or asleep. Some mechanical ventilators are more portable and can be carried or placed on a wheelchair. Talk to your pulmonologist to determine what type of mechanical ventilation is right for your child.1

How is non-invasive ventilation used in different types of SMA?

How often to use non-invasive breathing support is different for everyone with SMA. Some children may need breathing support only at night. Others may need it 24 hours a day. Breathing support needs can also vary over time. For example, children may need breathing support more often when they are sick.2

Your pulmonologist can advise you on when to use these methods. For example, a low blood oxygen level may be a sign that your child needs support. Here are common ways non-invasive breathing support is used in people with each type of SMA:

Type 1

Non-invasive breathing support is often used in infants with type 1 SMA, even before signs of breathing difficulty. This can help prepare for breathing failure and reduce chest defects. Nearly all children with type 1 SMA breathe better during sleep with some form of ventilation.1,2

Face masks do not work well for every child or family. Some potential problems include skin irritation or a poor fit. Your care team can work with you to find solutions to these problems.1,2

Type 2

The level of breathing support for children with type 2 SMA varies greatly. Non-invasive breathing support is usually used at some point in all children with type 2 SMA. Some children may not need much regular breathing support. Others may need BiPAP or a ventilator during sleep or when sick.1,2

Type 3 or 4

People with type 3 or 4 SMA usually have normal breathing function. Doctors should still perform regular tests for lung function and refer to a pulmonologist if concerns arise. Non-invasive breathing support may be needed when sick.1,2

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