Incidence and Characteristics of Respiratory Distress Syndrome in Preterm Infants

Respiratory distress syndrome is among the leading causes of respiratory distress and respiratory failure in premature infants. This, therefore, calls for mechanical ventilation so as to increase the chances of survival for those babies. Infants with respiratory distress syndrome, RDS, are associated with increased mortality and morbidity rates. Most of the developing countries have reported increased mortality rates despite the availability of the respiratory care units for the infants (Bellani et al., 2016). The chances of survival for the infants with RDS who required to be mechanically ventilated were 25% for the children with a birth weight of <1000 grams and the survival rates for those with the birth weight of >2500 grams was 53%. The study aimed at determining the incidence of severe RDS in the pediatric care unit at Gertrude’s Children’s Hospital together with the primary characteristics of the infants with RDS. The other objective is aimed at identifying the survival rates and the mortality risk factors of these infants.

Introduction

Over the years there have been increased mortality rates associated with RDS despite the technological advancements. RDS is a respiratory condition resulting from failure of the production of surfactant, a substance released by the body to enhance lung maturation (Martin et al., 2010). Prematurity is associated with inability of the lungs to produce surfactant especially for infants who have not reached 28 weeks of gestation. The infants who present with severe symptoms of the disease are less likely to respond well. In addition, those with low birth weight and Apgar score have poor treatment outcomes.  Therefore there is a close relationship between the development of RDS and reduced gestational age. The mortality for infants with RDS can be prevented by prenatal administration of steroids to enhance lung maturation as well as proper management for the children who are predisposed to development of the condition (Kinsella et al., 2016). The prenatal characteristics as well the severity of the respiratory distress determine the treatment outcome.

Research

The study included a total of 200 premature infants who had the clinical manifestations for RDS as well as the positive radiological signs that required to be ventilated mechanically and be admitted to the pediatric intensive care unit. The mean gestational age was at 30 weeks while the birth weight was 1665. F or the infants with RDS, at Gertrude’s pediatric hospital, a standard protocol is used which includes; maintenance of a thermally neutral environment, administration f humidified oxygen as well as noninvasive monitoring of cardiorespiratory system and minimal manipulation of the infants. For the study subject, there was the utilization of limited pressure time cycled mechanical ventilation along with pediatric neural ventilation (Kinsella et al., 2016). All the premature infants who had the manifestations of RDS clinically as well as the actual radiological examination were administered with the surfactant. 43% of the total infants, 34% were not given the surfactant since it was not available at the time when the research study was in process.

Discussion

Respiratory distress syndrome is a respiratory condition which affects one in every a hundred infants and is associated with high mortality rates among the infants who are born prematurely (Martin et al., 2010).  In the developed countries the number of prematurely born infants is approximately 12 of the total births, and this number tends to increase in these countries. Out of the total infants who are born prematurely, 10% develop respiratory distress. Therefore the risk of RDS rises with the prematurity. For instance, out of the total number of children who are born before 29 weeks of gestation, 60% have a greater chance of developing RDS, this is contrary to the infants who are born term since they have a subtle chance of developing this disease or the other associated illness (Speer, 2011). Moreover, the development of RDS is associated with some maternal risk factors such as, reduced maternal body mass, low prenatal care, low social, economic status, as well as diabetes. In the United States, there has been a decline in the mortality rate associated with RDS due to the surfactant replacement therapy (Bellani et al., 2016).

Each year, 80% of the total born infants are born before reaching 27 weeks gestation, and they end up developing the respiratory distress syndrome (Lista et al., 2010). This was also evident at Gertrude’s children’s hospital that all those infants who had not reached the gestation of 28 weeks developed RDS. The development of the RDS is highly associated with surfactant deficiency, an enzyme which is produced after 28 weeks of gestation so as to enhance lung maturity. The incidence of RDS increases with reduced gestation age. With antenatal administration of glucocorticoids for those women who are at risk of delivering premature infants, it can go a long way in reducing the severity, incidence and mortality rates associated with RDS.

Immediately after birth, preterm infants who have RDS tend to have difficulty in breathing, presents with grunting, poor, diminished breath sounds and labored breathing. At Gertrude’s hospital, it was noted that the infants who had severe RDS responded poorly to the treatment plan. For these babies, respiratory failure can result due to apnea, fatigue, and hypoxia and air leak from injury of the alveoli as a result of stiff lungs requiring high positive pressure (Lista et al., 2010). With proper management with oxygen therapy, positive airway pressure, ventilator, and surfactant, there is the improvement of the respiratory distress symptoms within 2-4 days and total resolving by 14days. It is always important to provide respiratory support together with optimal oxygen levels. The most critical management of RDS is the administration of surfactant through an endotracheal tube. This improves to a greater level gaseous exchange, and this helps in the reduction of the mortality rate by 405, air-leak by approximately 65% and chronic lung disease (Speer, 2011). However, it is crucial to note that this management does not influence in any way the neuro-developmental as well as the long-term pulmonary outcomes.

Out of the total number of infants that were admitted in 2015 in the pediatric intensive care unit, 693 of the total hospitalized premature infants had RDS.  30% were put on positive pressure ventilation (Speer, 2011). It was required that all the infants who had been confirmed to have the RDS both clinically and due to the radiological examination, were administered with surfactant replacement therapy which was supposed to be carried out in two doses. This was done for a total of 83 infants who were equal to 65.8% of the two total study subjects.  The majority of the neonates, 80%  had been born at Gertrude’s pediatric hospital as well as others had been transferred from other maternity hospitals since Getrude’s hospital was a referral center for most of the pediatric cases. From the study, it was found out that there was a tremendous relationship between the prenatal characteristics and severity of the disease with the treatment outcome. Those infants who were born with extremely low birth weight, low Apgar score been 1-5, and those were small for gestation had been associated highly with increased mortality rates. However, there was no high association of the death rate with other disease conditions (Lista et al., 2010).  Infants who had pulmonary hemorrhage had an increased chance of dying, though the mortality rate was decreased for the infants who had sepsis.

Conclusion

From the study it is evident that RDS is a major disease that affects the premature infants and that the development of the condition is inversely proportional to the gestational age. Moreover, there is a close relationship between the prenatal characteristics and the severity of the RDS symptoms with the treatment outcome of the disease. This, therefore, calls for proper management of pregnant mothers to ensure high maturity of their pregnancy as well as administration of steroids for those women who are unable to maintain the pregnancy up to the age of 28 weeks. More studies should be done on the proper interventions for the children who are born prematurely so as to increase their survival rates. Also, more research should be done to help in the prevention of mortality rates associated with RDS.

References

Ballard, R. A., Truog, W. E., Cnaan, A., Martin, R. J., Ballard, P. L., Merrill, J. D., ... & Null, D. R. (2016). Inhaled nitric oxide in preterm infants undergoing mechanical ventilation. New England Journal of Medicine, 355(4), 343-353.

Bellani, G., Laffey, J. G., Pham, T., Fan, E., Brochard, L., Esteban, A., ... & Ranieri, M. (2016). Epidemiology, patterns of care, and mortality for patients with acute respiratory distress syndrome in intensive care units in 50 countries. Jama, 315(8), 788-800.

Ferguson, N. D., Cook, D. J., Guyatt, G. H., Mehta, S., Hand, L., Austin, P., ... & Granton, J. T. (2013). High-frequency oscillation in early acute respiratory distress syndrome. New England Journal of Medicine, 368(9), 795-805.

Kinsella, J. P., Cutter, G. R., Walsh, W. F., Gerstmann, D. R., Bose, C. L., Hart, C., ... & George, T. N. (2016). Early inhaled nitric oxide therapy in premature newborns with respiratory failure. New England Journal of Medicine, 355(4), 354-364.

Lista, G., Fontana, P., Castoldi, F., Cavigioli, F., & Dani, C. (2010). Does sustained lung inflation at birth improve outcome of preterm infants at risk for respiratory distress syndrome?. Neonatology, 99(1), 45-50.

Martin, R. J., Fanaroff, A. A., & Walsh, M. C. (2010). Fanaroff and Martin's neonatal-perinatal medicine: diseases of the fetus and infant. Elsevier Health Sciences.

Patel, R. M., Kandefer, S., Walsh, M. C., Bell, E. F., Carlo, W. A., Laptook, A. R., ... & Hale, E. C. (2015). Causes and timing of death in extremely premature infants from 2000 through 2011. New England Journal of Medicine, 372(4), 331-340.

Speer, C. P. (2011). Neonatal respiratory distress syndrome: an inflammatory disease?. Neonatology, 99(4), 316-319.