Respiratory distress syndrome (RDS)
Shortly after birth, a 33-week gestation infant develops tachypnea, nasal
flaring, and grunting and requires intubation. Chest radiograph shows a
hazy, ground-glass appearance of the lungs.
Deficiency of mature surfactant (surfactant matures biochemically over
gestation; therefore, the incidence of surfactant deficiency diminishes toward
term.)
Inability to maintain alveolar volume at end expiration → decreased FRC
(functional residual capacity) and atelectasis
Primary initial pulmonary hallmark is hypoxemia. Then, hypercarbia and
Transient tachypnea of the newborn (TTN)
Meconium aspiration
respiratory acidosis ensue.
Diagnosis
Best initial diagnostic test—chest radiograph
Findings: ground-glass appearance, atelectasis, air bronchograms
Most accurate diagnostic test—L/S ratio (part of complete lung
profile; lecithin-to-sphingomyelin ratio)
Done on amniotic fluid prior to birth
Best initial treatment—oxygen
Most effective treatment—intubation and exogenous surfactant
administration
Primary prevention
Avoid prematurity (tocolytics)
Antenatal betamethasone