Infant Respiratory Distress Syndrome – Definition, and Complications.

Definition

Infant respiratory distress syndrome (IRDS) is a lung disorder that complicates the breathing process of newborns. This disorder is more common in premature infants. It occurs due to insufficient surfactant in the lungs. A surfactant is composed of proteins and fats, which helps the lungs to be inflated and prohibits the lung sacs from collapsing. Surfactant starts producing between 24 and 28 weeks of pregnancy and by the 34^th week, most cases of normal babies produce abundant surfactant.

 

Other names of Infant respiratory distress syndrome are as follows.

• Hyaline Membrane Disease in Newborns
• Neonatal Respiratory Distress Syndrome
• Surfactant Deficiency in Newborns

Function of surfactant in lungs

The surfactant is produced by the cell lining called hyaline membranes in the airways of the lungs. It reduces the surface tension of airways and makes the alveoli to be inflated. When there is a scarcity of surfactant, alveoli start to collapse for each breath by the infant. That’s why your baby breathes very hard to re-inflate the collapsed airways.

For such reasons lungs function decreases, therefore very low oxygen is absorbed and more carbon dioxide is lagged in the bloodstream. This condition leads to acidosis (increased acidic condition of the blood), which affect the other organs in the body. Eventually, your baby becomes disabled to breathe if it is untreated.

 

Epidemiology of infant respiratory distress syndrome

Respiratory misery syndrome confronts very less in growing developed countries than somewhere else, primarily because most premature toddlers who’re small for their gestation are stressed in the uterus because of pregnancy-caused high blood pressure or malnutrition. Most deliveries in growing countries arise at home, accurate information in these areas is unavailable to decide the frequency of respiration misery syndrome.

In the US, IRDS has been envisioned to occur in 20,000-30,000 newborn infants every year and is a hassle in about 1% pregnancies. Approximately 50% of the neonates born at 26-28 weeks gestation develops IRDS, while less than 30% of premature neonates born in 30-31 weeks gestation develops the situation.  Normally, IRDS occurs most usually in white premature toddlers.

History

• In 1967, Ashbaugh et al described the acute respiratory syndrome.
• In 1988, they elaborated the theory of RDS as quantified impairment of respiration.
• In 1994, a new definition was recommended by the American-European Consensus Conference Committee, which defines the severity of the pulmonary injury.
• In 2012, European Society of Intensive Care Medicine revised the definition of RDS to improve the clinical presentation and terminology.

Causes and Risk factors of IRDS

• When newborn’s lungs are not fully developed. If the lungs are less developed the chances of getting IRDS is high
• IRDS occurs when there is no enough slippery substance called surfactant in the alveoli of the lungs.
• It can also be due to the genetic inheritance of lung problems
• In general, babies develop IRDS if they were born before 34^th When there is diabetes in the pregnant mother chances of getting IRDS is more
• Family members who had IRDS earlier
• Induced labor and cesarean delivery before the baby is full term
• Fast labor
• Multiple pregnancies (Triplets or twins)
• Premature delivery
• Neonatal infection
• Heavy stress during baby delivery, especially in the case of high blood loss
• Planned C- section delivery increases the risk of an IRDS
• A Sudden accident or damage to the uterus of pregnant woman
• perinatal asphyxia (lack of air immediately before, during or after birth)
• Cold stress
• Infants with patent ductus arteriosus
• Pulmonary hemorrhage
• Congenital diaphragmatic hernia and pulmonary hypoplasia
• Lung transplantation

Infant respiratory distress syndrome – Complications

Acute complications

• Air leaks out of the lungs and get trapped in the chest cavity
• Pulmonary hemorrhage
• Cerebral hemorrhage

Chronic complications

• Bronchopulmonary dysplasia due to the use of ventilators. Ventilators disturb the normal growth of the lungs.
• Lack of oxygen to brain leads to certain developmental disabilities such as
• Learning difficulties
• Debilitated vision
• Impairment of hearing function
• Sepsis
• Tension pneumothorax
• Neonatal death
• Kidney failure in cases of severe IRDS
• Infection of blood
• Blood clots
• Retardation of mental health

Symptoms of infant respiratory distress syndrome

Symptoms occur within minutes of baby birth. Each baby may vary different symptoms. Some of the common symptoms are ass follows:

• Grunting sounds when breathing
• Difficulty breathing at birth that gets progressively worse
• Chest retractions (pulling in at the ribs and sternum during breathing)
• Flaring of the nostrils
• Tachypnea (rapid breathing)
• Cyanosis (blue coloring)

Chest retractions

Cyanosis

Diagnosis and test

It is diagnosed by carrying out some assessments such as

Blood gas analysis: Test for oxygen, carbon dioxide and acid in the body fluids. blood gas test will often show the lowered amount of oxygen, increased carbon dioxide and the excess amount of body fluid acid.

Colour, appearance and breathing efforts will indicate the need of oxygen for baby.

X-ray of lungs: X-ray images of lungs shows a unique “ground glass” appearance called a reticulogranular pattern.

Diffuse ground-glass appearance in both lungs

Echocardiography: Sometimes it is used to find out some heart problems that might cause similar symptoms to HMD

Treatment and medications

Treatments for Infant respiratory distress syndrome include

• Placing a breathing tube (also called endocardial tube) into baby’s air pipe
• Infants will be kept in warm condition with moist oxygen and oxygen level is monitored to avoid side effects
• Aided ventilation with ventilator can be life-saving for babies. Use of this machine may damage the tissue of the lungs. So if possible this treatment is avoided.
• Continuous positive airway pressure (CPAP) – a mechanical breathing machine that pushes a continuous flow of air or oxygen to the airways to help keep tiny air passages in the lungs open
• Surfactant replacement with an alternate artificial surfactant. This treatment will reduce the difficulty of HMD and it is most effective if it is started first six hours of birth. It may be given as preventive treatment for babies at very high risk for HMD or used as a “rescue” method. The drug comes as a powder that is mixed with sterile water and given through the ET tube. This treatment is usually administered in several doses. The amount of surfactant is determined by the patient weight.
• Medications may help sedate and to ease of babies pain during treatment

Continuous positive airway pressure (CPAP)

Prevention of infant respiratory distress syndrome

• To stimulate the fetal surfactant production and lung maturation, the drug such as antenatal corticosteroids (dexamethasone) can be used. this will reduce IRDS, intraventricular hemorrhage and mortality by 40%
• Delaying premature birth. Tocolytics – eg, atosiban, nifedipine or ritodrine – may delay delivery by 48 hours and therefore enable time for antenatal corticosteroids to be given
• Control diabetes during maternity period
• Avoid hypothermia in the neonate
• Inhaling nitric oxide will reduce pulmonary inflammation and increase oxygenation. If it began early after birth it improves the acute disease and also reduces the chance of chronic lung disease