Nebulized Surfactant Shows Promise in
Large Cohort

Jennie Smith

November 13, 2020

Nebulized delivery of surfactant reduced the need for intubation and liquid surfactant administration by half among newborns with signs of respiratory distress syndrome, according to results from a large randomized, multicenter trial.

Neonatologists have long sought alternatives to intubation for administering surfactant to newborns with respiratory distress syndrome (RDS). An effective noninvasive aerosolized treatment has remained elusive, with small clinical trials that have produced mixed results.

In research published in Pediatrics, James J. Cummings, MD, of Albany (N.Y.) Medical Center, and colleagues, randomized 457 infants (mean 33 weeks' gestational age) with signs of RDS to either usual care or a nebulized bovine surfactant. Infants were recruited at 22 neonatal ICUs in the United States.

Investigators were not blinded to treatment allocation and the decision to intubate was left up to the individual treating physician, because to do so, the authors wrote, would add "pragmatic strength" to the study, and "be ethically compliant with the infant's best interest."

Infants in the study received usual care or up to three treatments 4 or more hours apart of 35 mg/mL calfactant suspension, 210 mg phospholipid/kg body weight delivered into the mouth through a nebulizer modified with a pacifier. Cummings and colleagues found that intubation and liquid surfactant administration within the first 4 days after birth was 26% in the intervention group and 50% in the usual care group (P < .001).

The results remained significant after investigators adjusted for gestational age, birth weight, age when randomized, sex, delivery mode, and antenatal steroids. Rates of intubation for surfactant administration were lower for infants in the intervention group in all gestational age brackets except the youngest (23-24 weeks); all of these infants needed intubation. Respiratory support at days 3, 7, and 28 did not differ between study groups.

"Our study is the first to reveal the efficacy of an aerosolized surfactant delivery system that does not require a respiratory circuit interface," the investigators wrote.

In previous trials of aerosolized surfactants, they noted, treatment was delivered with nasal continuous positive airway pressure. "By using a separate, pacifier interface, both the aerosol delivery and [nasal continuous positive airway pressure] flow can be managed independently, which should allow for safer patient care."

Cummings and colleagues also acknowledged several important limitations of their study, including its nonmasked, nonblinded design, and that it enrolled few infants with less than 28 weeks' gestation. It takes 1-2 hours to deliver aerosolized calfactant, and "we did not want to delay definitive treatment."

In an editorial comment accompanying the study, Kirsten Glaser, MD, of the University of Leipzig (Germany), and Clyde Wright, MD of the University of Colorado at Denver, Aurora, called the results promising. "Importantly, application of surfactant aerosols was well tolerated by using a modified nebulizer with a pacifier interface."

The editorialists cautioned, however, of the study's strong potential for selection bias. "Clinicians were aware that every infant randomly assigned to the nebulized surfactant arm received the intervention," they wrote. "It is possible that clinicians delayed intubation and endotracheal surfactant instillation in this group, being biased by aerosolization and the hypothesis of lower risk of air leak and lung injury."

Glaser and Wright further lamented that there were no formal criteria for administering surfactant therapy, and that the infants in the study might not be representative of those most in need of treatment. Today, bronchopulmonary dysplasia "primarily affects infants born at less than 28 weeks' gestational age," a minority of the infants recruited for this study, they wrote, urging further investigation in this patient group.

In an interview, neonatologist Roger F. Soll, MD, the H. Wallace Professor of Neonatology at the Larner College of Medicine at University of Vermont in Burlington, echoed the editorialists' concerns that the study's pragmatic design left a number of key questions unanswered.

"It's a promising study that laudably recruited on an order of magnitude more infants than any like it in the past," Soll said. "And the kids who got the therapy seemed to do better, which is exciting. But with the broad entry criteria, the lack of formal diagnosis of RDS, and the outcome measures ultimately potentially biased by lack of blinding, it doesn't give us the answers we need yet to consider aerosolized treatment."

ONY Biotech, manufacturer of the study drug Infasurf, sponsored the trial. Cummings and one coauthor disclosed consulting arrangements with the sponsor, and another coauthor is an employee of the sponsor. The remaining investigators had no relevant financial disclosures. Glaser and Wright disclosed no conflicts of interest related to their editorial; Wright's work was supported by the National Institutes of Health. Soll is president of the Vermont Oxford Network and coordinating editor of Cochrane Neonatal.

SOURCE: Cummings JJ et al. Pediatrics. 2020;146(5):e2020021576.

This article originally appeared on MDedge.com, part of the Medscape Professional Network.

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