Recommendations for neonatal surfactant therapy – addendum

Abstract

Francais en page 139 How should surfactant be used in preterm infants initially managed with nasal continuous positive airway pressure (CPAP)? Many centres providing neonatal intensive care have increased their use of CPAP as a first-line method of respiratory support for preterm infants. This practice shift started after several descriptive, as well as before/after cohort studies, suggested that avoiding intubation and mechanical ventilation may help to reduce bronchopulmonary dysplasia (BPD) (1,2). There has been concern, however, that adopting this practice might deprive some infants of the proven benefits of expeditiously administered exogenous surfactant, especially those born at the youngest gestational ages who have traditionally been provided with prophylactic treatment. Recent randomized trials comparing elective intubation and prophylactic surfactant to initial management with nasal CPAP and selective surfactant therapy, suggest that the latter approach is safe and reduces the number of infants intubated and given surfactant (3–7). In the largest of these studies, even the infants at highest risk for respiratory distress syndrome (RDS) and its associated complications (ie, those born at 24 to 25 weeks’ gestational age), appeared to fare as well, if not better, when initially managed with nasal CPAP (4). These studies suggest that application of nasal CPAP shortly after birth to very preterm infants is an acceptable alternative strategy to elective intubation and prophylactic surfactant treatment. However, the criteria for surfactant treatment of infants initially supported with nasal CPAP have been inconsistent. A short period of observation on CPAP is necessary to enable clinicians to identify infants with surfactant sufficiency or mild RDS, who may be effectively managed without endotracheal intubation and surfactant treatment. Yet, a delay in treating a newborn with significant surfactant deficiency could result in a suboptimal response and/or an increased risk of complications. Criteria for selective treatment of infants initially managed with CPAP are needed. Verder et al (8), who were early advocates of the INSURE (INtubate, SURfactant, Extubate) approach for infants with RDS, found that preterm infants with RDS initially managed with nasal CPAP had better outcomes when treated with surfactant when reaching a fraction of inspired oxygen (FiO2) of approximately 0.37 to 0.55 versus 0.57 to 0.77. A systematic review examining timing of surfactant administration to preterm infants with RDS initially managed with CPAP also found that earlier treatment was more effective (9). From this review, when a low treatment threshold (FiO2 ≤0.45) for intubation and surfactant administration in the early treatment group was used, protection from air leak and BPD was enhanced. Examining several recent, large randomized trials yields additional useful information that can be used to guide practice (3–7). The two studies that did not allow treatment with surfactant of infants initially managed with nasal CPAP, until the requirement for supplemental oxygen exceeded an FiO2 of 0.60, showed increased rates of pneumothorax compared with the group intubated and given surfactant shortly after birth (3,7). The studies in which selective treatment was provided at lower supplemental oxygen thresholds saw no increase in air leak (4–6). These observations are consistent with a previous systematic review that found that babies with or at high risk for RDS had better outcomes if surfactant was given earlier rather than later in the clinical course (10). However, the prophylactic administration of surfactant with rapid extubation to nasal CPAP for infants at risk of RDS does not appear to convey an additional advantage compared with selective treatment after a short period of nasal CPAP, as long as the threshold for treatment is not too high (5,6).