Respiratory Distress Syndrome Of Newborns - A Brief Discussion

Introduction
Respiratory Distress Syndrome of the newborns (RDS) also known as hyaline membrane disease is a breathing disorder of premature newborns in which the air sacs (alveoli) in a newborn’s lungs do not remain open because the production of a substance that coats the alveoli (surfactant) is absent or insufficient. This disease is mainly confined to premature babies. Insufficient surfactant leads to alveolar collapse; re-inflation with each breath exhausts the baby, and respiratory failure follows. Hypoxia leads todecreased cardiac output, hypotension, acidosis and renal failure. It is the
major cause of death from prematurity.

Risk factors:

• Preterm babies ( 91%risk if born at 23–25 weeks; 52% risk  if 30–31 weeks.)  
• Maternal diabetes,
• Male babies, 
• 2nd twin, 
• Caesarean deliveries.

Clinical Signs 

• Respiratory distress shortly after birth (within first 4 hours)
• tachypnoea ( respiratory rate >60/min),
• grunting, 
• nasal flaring, 
• intercostal recession and 
• cyanosis. 

Chest X ray shows diffuse granular patterns (ground glass appearance) ± air bronchograms.

Differential Diagnosis 

1. Transient tachypnoea of the newborn (TTN) is due to excess lung fluid. It usually resolves after 24 hours. 
2. Meconium aspiration ;
3. Congenital pneumonia (group B strep); 
4. Tracheo-oesophageal fistula (suspect if respiratory problems after feeds); 
5. Congenital lung abnormality; 
6. Sepsis.

Prevention 

Betamethasone or dexamethasone should be offered to all women at risk of preterm delivery from 23–35 weeks. Mothers at high risk should be transferred to perinatal centers with experience in managing RDS.

Treatment 

• Delay clamping of cord by 3 min to promote placento–fetal transfusion. 
• Wrap up to keep warml and take to NICU incubator.
• Give oxygen via an oxygen–air blender, using lowest concentration of O2 possible provided there is an adequate heart rate response. 
• If spontaneously breathing stabilize with CPAP (5–6cm H2O).
• Babies at high risk of RDS should get natural surfactant (reduces mortality and air leaks). 
• If gestation is less than or equal to 26 weeks, intubate and give prophylactic surfactant via ET tube ± 2 further doses if ongoing O2 demand or ventilation requirement.
• Rock gently to aid spread in the bronchial tree. 
• Monitor O2, as needs may suddenly decrease.  
• Aim for saturations between 85–93% to reduce risk of retinopathy of prematurity and bronchopulmonary dysplasia. 
• Some centers give a dose of surfactant then extubate pending developments; others keep the baby intubated and extubate as tolerated.
• If blood gases worsen, intubate and support ventilation before fatigue sets in. 
• Fluids: Give 10% glucoseintravenously. 
• Nutrition: Get help. Inositol is an essential nutrient promoting surfactant maturation and plays a vital role in neonatal life. Supplementing nutrition of premature babies with inositol reduces complications
• Full parenteral nutrition can be started on day 1. 
• Minimal enteral feeding can also be started on day 1. 

Signs of a Poor Prognosis 

Persistent pulmonary hypertension, 

large right to left shunt via the ductus; 

increased dead-space fraction in lungs. 

Unfortunately if, despite trying everything, hypoxia worsens, it means the the baby is dying. Discuss with the senior doctor. . Explain what is happening to the parents, and that the baby will feel no pain. Encourage the parents to spend time with their baby and when appropriate the tubes may be disconnected for peaceful death.