Lung Deposition of Surfactant Delivered via a Dedicated Laryngeal Mask Airway in Piglets

Alternative routes of surfactant application - An update

Non-invasive modes of respiratory support have been shown to be the preferable way of primary respiratory support of preterm infants with respiratory distress syndrome (RDS). The avoidance of invasive mechanical ventilation can be beneficial for preterm infants in reduction of morbidity and even mortality. However, it is well-established that some infants managed with non-invasive respiratory support from the outset have symptomatic RDS to a degree that warrants surfactant administration. Infants for whom non-invasive respiratory support ultimately fails are prone to adverse outcomes, occurring at a frequency on par with the group intubated primarily. This raises the question how to combine non-invasive respiratory support with surfactant therapy. Several methods of less or minimally invasive surfactant therapy have been developed to address the dilemma between avoidance of mechanical ventilation and administration of surfactant. This paper describes the different methods of less invasive surfactant application, reports the existing evidence from clinical studies, discusses the limitations of each of the methods and the open and future research questions.

Surfactant delivery strategies to prevent bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is one of the most devastating morbidities of preterm infants. Antenatal factors like growth restriction and inflammation are risk factors for its development. Use of oxygen and positive pressure ventilation, which are often necessary to treat respiratory distress syndrome (RDS), increase the risk for development of BPD. Continuous positive airway pressure (CPAP) as primary respiratory support allows for avoidance of positive pressure ventilation in many cases but may lead to a delay of surfactant administration which is a proven therapy for RDS. Several alternative surfactant delivery strategies, including nebulization of surfactant, pharyngeal instillation of surfactant, delivery of surfactant via supraglottic airway device or surfactant delivery via a thin endotracheal catheter have been described which allow for the benefit of surfactant therapy while on CPAP. This review reports available data and discusses the existing evidence of their value in preventing BPD as well as further research directions.

Randomized Trial of Surfactant Therapy via Laryngeal Mask Airway Versus Brief Tracheal Intubation in Neonates Born Preterm

OBJECTIVE

To evaluate the possible noninferiority of surfactant administration via laryngeal mask airway (LMA) vs endotracheal tube (ETT) in avoiding the requirement for mechanical ventilation in preterm neonates with respiratory distress syndrome (RDS).

STUDY DESIGN

This was a randomized controlled trial including infants born at 27 to 36 weeks of gestation, >800 g, diagnosed with RDS and receiving fraction of inspired oxygen 0.30-0.60 via noninvasive respiratory support. Infants were randomized to surfactant via LMA (with atropine premedication) or ETT (InSuRE approach with atropine and remifentanil premedication). Primary outcome was failure of surfactant treatment to prevent the need for mechanical ventilation.

RESULTS

Patients were randomized, 51 to LMA and 42 to the ETT group. Both groups had similar baseline characteristics, with birth weights ranging from 810 to 3560 g. Failure rate was 29% in the ETT group and 20% in the LMA group (P = .311). This difference was due to early failures (within 1 hour), with 12.5% in the ETT group and 2% in the LMA group (P = .044). Surfactant therapy via LMA was non-inferior to administration via ETT; failure risk difference -9.0% (CI -∞ to 5.7%). Efficacy in decreasing fraction of inspired oxygen, number of surfactant doses administered, time to wean off all respiratory support, rates of adverse events, and outcomes including pneumothorax and BPD diagnosis did not differ between groups.

CONCLUSIONS

Surfactant therapy via LMA was noninferior to administration via ETT and it decreased early failures, possibly by avoiding adverse effects of premedication, laryngoscopy, and intubation. These characteristics make LMA a desirable conduit for surfactant administration.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02164734.