Respiratory distress syndrome (RDS) is a life-threatening lung disorder that commonly affects premature infants. Respiratory distress syndrome results from insufficient levels of surfactant, a foamy fluid substance produced by the body between the 34th and 37th week of pregnancy. Surfactant is essential for the expansion of the alveoli or air sacs of the lungs. When an infant is born prematurely, their lungs have not produced the necessary amount of surfactant. Without surfactant, the lungs cannot inflate, resulting in RDS.
- RDS affected an estimated 24,000 infants born alive in the United States in 2003.
- The incidence of RDS declines with degree of maturity at birth. It occurs in 60 percent of babies born at less than 28 weeks’ gestation, 30 percent of those born at 28 to 34 weeks, and less than 5 percent of those born after 34 weeks.
- Annual RDS deaths decreased from 25,000 in the 1960’s to 831 in 2003, representing 4 percent of infant fatalities. In 2003, the syndrome was the seventh-ranking cause of infant deaths.
- In 2003, the RDS mortality rate (per 100,000 live births) among African Americans was 43.7, versus 16.8 among whites—a difference of more than 62 percent.
- RDS is characterized by rapid breathing, nasal flaring, grunting noise with each breath, and blue around lips and nail beds, which indicates a lack of oxygen. Symptoms usually appear shortly after birth and become more severe over time.
- RDS infants may develop several complications such as sepsis, an infection of the bloodstream, as well as other problems related to prematurity, such as bleeding into the brain. These and other complications can cause convulsions, shock-like states, and in some cases, death.
- Complications such as pneumothorax (collapse of lung) and long-term complications such as bronchopulmonary dysplasia may develop as a result of oxygen toxicity, high pressures delivered to the lungs during mechanical ventilation or the severity of the condition itself.
- RDS is treated by general supportive therapy, such as the administration of intravenous fluids, by the use of mechanical respirators designed to prevent the alveoli (air SACS) from collapsing, by the administration of surfactant, and, for those infants with severe RDS, by the use of partial liquid ventilation which involves instillation of a special oxygenated liquid to the lungs.
- RDS may be prevented or ameliorated by treating women at high risk for a premature delivery with certain hormones that could speed up the baby’s lung development or administering surfactant in infants at birth, increasing survival.