Development And Validation Of A Clinical RD Score For Decision Making For Administration Of Surfactant In Preterm Babies With RDS (Respiratory Distress Syndrome) - A Prospective Observational Study

Respiratory distress syndrome, also known as hyaline membrane disease, occurs almost exclusively in premature infants. The incidence and severity of respiratory distress syndrome are inversely related to the gestational age of the newborn infant. The incidence of RDS is around 60 - 80% among infants < 28 weeks, 30-40% between 28-34 weeks, less than 5% at 34 weeks and is rarely seen among those > 37 weeks.

The availability of continuous positive airway pressure (CPAP) and natural surfactant have revolutionised the management of RDS. In 1967, Gregory et al. reported the value of application of continuous positive airway pressure in the management of RDS. Successful surfactant replacement therapy in RDS was reported by Fujiwara et al. Besides the use of Continuous positive airway pressure and surfactant replacement, the other advances include: Use of antenatal steroids to enhance pulmonary maturity, appropriate resuscitation and immediate use of CPAP for alveolar recruitment, Use of gentler modes of ventilation like patient triggered ventilation, Supportive therapies, such as the diagnosis and management of patent ductus arteriosus (PDA), fluid and electrolyte management, trophic feeding and nutrition.

The use of CPAP applied to the alveoli has been shown to stabilise and improve respiratory distress in preterm babies. It preserves the action of endogenous surfactant and may also obviate the need for surfactant in a substantial number of cases. CPAP is cost effective and more patient friendly than mechanical ventilation. Availability of CPAP even at the district level Special Newborn Care Unit (SNCU) in various states across the country make it an ideal candidate for respiratory support in the high risk population.

In addition to optimal respiratory support in the form of continuous positive airway pressure (CPAP) or mechanical ventilation and good supportive care, surfactant replacement therapy (SRT) forms the mainstay in the management of RDS. Since the report by Fujiwara in 1980 of the first successful use of SRT, numerous randomized controlled trials (RCTs) and their meta-analyses have established its efficacy in reducing mortality and air leak syndromes in RDS. Almost all the trials evaluating the role of SRT were conducted in high-income countries. Not surprisingly, SRT is the standard of care in neonates with RDS in these countries.

The population in low and middle income countries (LMIC) like India may differ significantly from the western world. But whether the evidence from these high income countries can be extrapolated to LMICs, still remains questionable. High cost of surfactant therapy, issue regarding regular supply of the drug, lack of skilled personnel, poor antenatal steroid coverage of mothers with preterm labour, higher incidence of perinatal hypoxia/ischemia and infections all complicate the clinical course of RDS. The paucity of evidence for efficacy and/ or safety of SRT in these settings further add to the complexity.