What is neonatal respiratory distress syndrome?
Neonatal respiratory distress syndrome (NRDS) is a serious medical condition where a newborn baby's lungs cannot provide their body with enough oxygen.
NRDS is also known as hyaline membrane disease, infant respiratory distress syndrome or newborn respiratory distress syndrome.
Why it happens
NRDS most often occurs when there is not enough of a substance called surfactant in the lungs. This substance, made up of proteins and fats, helps keep the lungs inflated and prevents parts of the lung called air sacs from collapsing.
Your baby will normally begin to produce surfactant sometime between weeks 24 and 28 of pregnancy. Most babies will have produced enough surfactant to breathe normally by week 34. If your baby is born prematurely, they may not have enough surfactant in their lungs.
Occasionally, NRDS occurs in babies that are not born prematurely. This is usually due to a problem with the genes that play a role in lung development.
It's estimated that half of all babies born before 28 weeks of pregnancy will develop NRDS.
Signs and symptoms
The signs of NRDS are usually noticeable immediately after birth and get worse over the following few days. They can include:
- blue-coloured lips, fingers and toes
- rapid, shallow breathing
- flaring nostrils
- a grunting sound when breathing
As premature babies are usually born in hospital, most babies with NRDS are already in hospital when they develop these problems.
However, NRDS can also affect babies born at home. If you give birth outside hospital and notice the above symptoms in your child, call immediately and ask for an ambulance.
Most babies with NRDS will need breathing help with extra oxygen and possibly some form of ventilator support. Babies needing ventilation can often be treated with a medication directly into the lungs called artificial surfactant, which helps restore normal lung function.
Some cases can be prevented or at least made less severe by treating the mother with a medication called betamethasone before birth.
Read more about treating neonatal respiratory distress syndrome.
In the majority of cases, NRDS can be successfully treated and deaths directly linked to NRDS are very rare.
However, in more severe cases there is a risk of further problems. These can include scarring to the lungs leading to longer term breathing problems. There is also a risk of brain damage, which may result in problems such as learning difficulties.
Read more about the possible complications of neonatal respiratory distress syndrome.
Diagnosing neonatal respiratory distress syndrome
A number of tests can be used to look for the signs of neonatal respiratory distress syndrome (NRDS) and rule out other possible causes.
These tests may include:
- a physical examination – to check for the distinctive signs and symptoms of NRDS
- blood tests – to measure the amount of oxygen in the blood and check for an infection
- a pulse oximetry test – to measure how much oxygen is being absorbed in the blood, using a sensor attached to the fingertip, ear or toe
- a chest X-ray – to look for the distinctive cloudy appearance of NRDS
- an echocardiogram – a type of ultrasound scan that is used to create a picture of the inside of the heart
Neonatal respiratory distress syndrome treatment
Treatment of neonatal respiratory distress syndrome (NRDS) aims to manage the underlying cause of the condition while supporting breathing.
Treatment before birth
Treatment for neonatal respiratory distress syndrome (NRDS) sometimes begins before birth. If you are thought to be at a significant risk of giving birth before week 34 of pregnancy, you will usually be given two injections a day of a steroid medication called betamethasone a few days before the delivery is expected.
Betamethasone helps stimulate the development of the baby’s lungs. It's estimated that the use of betamethasone prevents NRDS occurring in a third of premature births.
Treatment after the birth
If betamethasone is not used, or if it is unsuccessful in preventing NRDS, it's likely that your baby will be transferred to a neonatal unit.
For mild symptoms your baby may only need extra oxygen, usually given into an incubator or by nasal tubes (cannula). If symptoms are more severe, your baby will be attached to a machine to either support or take over their breathing. Often these treatments are started immediately in the delivery room before transfer to the neonatal unit.
As NRDS is usually caused by the lack of a protective substance in the lungs called surfactant, your baby may be given a dose of artificial surfactant. This is usually delivered through a breathing tube to help restore normal lung function.
Evidence suggests that early treatment (within two hours of delivery) is more beneficial than if treatment is delayed.
Your baby will also be given fluids and nutrients through a tube connected to one of their veins.
Some babies with NRDS will only require help with breathing for a few days, although others – usually those who are born extremely prematurely – may need support for weeks or even months.
Premature babies often have multiple problems that keep them in hospital, but generally they are well enough to go home around their original expected delivery date. However, the exact length of time your baby will need to stay in hospital will largely depend on how early they were born.
Complications of neonatal respiratory distress syndrome
There is a significant risk that babies who experience neonatal respiratory distress syndrome (NRDS) will develop further problems.
In some cases of NRDS, air can leak out of the lungs and become trapped in the chest cavity. This is known as pneumothorax.
The pocket of air places extra pressure on the lungs causing them to collapse and leading to additional breathing problems.
Air leaks can be treated by inserting a tube into the chest to allow the trapped air to drain.
Babies with NRDS may experience bleeding inside their lungs (pulmonary haemorrhage) and brain (cerebral haemorrhage).
Bleeding into the lungs can be difficult to treat but usually air pressure from a ventilator and transfusion of blood products allows the bleeding to stop.
Bleeding into the brain is quite common in premature babies, but fortunately most bleeds are mild and there are few longer term problems. Larger bleeds occasionally require surgery to drain accumulating fluid.
Bronchopulmonary dysplasia (BPD) is a long-term lung condition that can affect some children with NRDS. It develops when the ventilator used to treat NRDS causes scarring to the lungs that affects their development.
Symptoms of BPD include, rapid, shallow breathing and shortness of breath.
Babies with severe BPD usually require additional oxygen, through tubes into their nose, to help with their breathing. This is usually stopped after a few months when the lungs have healed.
However, children with BPD may require regular medication, such as bronchodilators, to help widen the airways of their lungs and assist with their breathing.
If the brain is damaged during NRDS, either due to bleeding or a lack of oxygen, it can lead to long-term developmental disabilities such as learning difficulties, movement problems, impaired hearing and impaired vision.
However, these developmental problems are not usually severe. For example, one survey estimated that three out of four children with developmental problems only have a mild disability that should not stop them leading a normal adult life.