Neonatal respiratory distress syndrome
Neonatal respiratory distress syndrome (NRDS) happens when a newborn baby's lungs aren't fully developed and they can provide enough oxygen. It usually affects premature babies.
NRDS is also known as:
hyaline membrane disease
infant respiratory distress syndrome
newborn respiratory distress syndrome
surfactant deficiency lung disease (SDLD)
Despite having a similar name, acute respiratory distress syndrome (ARDS) isn't related. ARDS is caused by a serious underlying health condition and can affect people of any age.
Why it happens
NRDS most often occurs when there isn't enough 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 collapsing.
A baby normally begins producing surfactant sometime between weeks 24 and 28 of pregnancy. Most babies produce 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 aren't born prematurely. This is usually due to other risk factors, such as:
the mother having diabetes
the baby being underweight
poor lung development, which can be caused by a variety of illnesses
Problems with the genes can play a role in lung development, but this is very rare.
It's estimated that half of all babies born before 28 weeks of pregnancy will develop NRDS. However, this has reduced in recent years, as steroid injections can be given to mothers at risk of NRDS duringpremature labour.
Signs and symptoms
The signs of NRDS are often noticeable immediately after birth and get worse over the following few days. They can include:
blue-coloured lips, fingers and toes
rapid, shallow breathing
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 and receive treatment (see below).
If you give birth outside hospital and notice the above symptoms in your child, call 999 immediately and ask for an ambulance.
A number of tests can be used to look for the signs of NRDS and rule out other possible causes.
These tests may include:
a physical examination
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
Most babies with NRDS 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 to 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.
In the majority of cases, NRDS can be successfully treated and deaths directly linked to NRDS are rare in the UK.
However, in more severe cases, there's a risk of further problems. These can include scarring to the lungs, leading to longer-term breathing problems. There's also a risk of brain damage, which may result in problems such as learning difficulties.
Treating neonatal respiratory distress syndrome
Treatment of neonatal respiratory distress syndrome (NRDS) aims to support the baby's breathing while treating the underlying cause.
Treatment before birth
If you're thought to be at a risk of giving birth before week 34 of pregnancy, treatment for NRDS can begin before birth. You'll usually be given two injections a day of a steroid medication called betamethasone, starting 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 isn't used, or if it's unsuccessful in preventing NRDS, it's likely that your baby will be transferred to a neonatal unit.
You baby may only need extra oxygen if the symptoms are mild; it's usually given into an incubator or by nasal tubes. If symptoms are more severe, your baby will be attached to a machine to either support or take over their breathing. These treatments are often started immediately in the delivery room before transfer to the neonatal unit.
Your baby may also be given a dose of artificial surfactant, usually delivered through a breathing tube.
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 only require help with breathing for a few days, although others – usually those 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're well enough to go home around their original expected delivery date. However, the exact length of time your baby needs to stay in hospital largely depends on how early they were born.
Complications of neonatal respiratory distress syndrome
Babies who experience neonatal respiratory distress syndrome (NRDS) have a significant risk of developing 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, which 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 asbronchodilators, 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 andimpaired 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, which shouldn't stop them leading a normal adult life.