Question

Respiratory distress syndrome occur in patients which lack

• A. Larynx
• B. Dipalmitoyl lecithin
• C. Surfactant
• D. Both b and c

Answer 1

Answer: (D)

Both b and c

"Respiratory distress syndrome" also known as "Hyaline membrane disease" or "Surfactant deficiency disorder" is a syndrome caused due to structural immaturity of the lungs and lack of a slippery substance in the lungs called surfactant. It can also result from a genetic problem linked with the production of surfactant associated proteins. Most cases of RDS occur in babies born before 37 weeks. The less the lungs are developed, the higher the chance of RDS after birth. The problem is uncommon in babies born full-term (at 40 weeks).
Surfactant is a surface-active lipoprotein complex secreted by the cells of the alveoli that serves to reduce the surface tension of the lungs. Surfactant increase pulmonary compliance ( the ability of lungs and thorax to expand). It prevents atelectasis (collapse of the lung) at the end of expiration. It facilitates recruitment of collapsed airways. It reduces fluid accumulation and keeps the airways dry by reducing these forces.
"Dipalmitoyl lecithin" act as a surfactant in the lungs. It is found in the extracellular lipid layer, lining the pulmonary alveoli, allowing it to ventilate. It develops in the lungs after the 30th week of gestation. Premature infants do not have an adequate amount of this surfactant, which may cause death due to respiratory distress syndrome.