Surfactant and continuous positive airway pressure in infants with respiratory distress syndrome

The treatment of respiratory distress syndrome (RDS) in low birth weight infants (LBW) usually involves surfactant administration, mechanical ventilation and nutritional support. However, a more gentle ventilatory approach using early surfactant administration followed quickly by extubation and use of nasal continuous positive airway pressure (CPAP) instead of mechanical ventilation has been shown to be successful for many of these infants with less adverse sequelae. In fact, the use of mechanical ventilation in premature RDS infants often results in barotrauma, volutrauma and chronic lung disease.
CPAP prevents alveolar collapse and helps maintaining functional residual capacity at end expiration. There are essentially two approaches to CPAP therapy in RDS. The first is the INSURE approach (INtubation, SURfactant and Extubation), involving intubating babies only to administer the surfactant and quickly extubating them to nasal CPAP. The second is the Columbia approach, in which infants are started on CPAP in the delivery room and intubation is considered only if they meet the criteria for surfactant administration and mechanical ventilation later.
Overall, the INSURE approach has consistently shown a reduction in the need for mechanical ventilation in the LBW infants, with an indirect effect on the incidence of BPD. With this approach, intubation is used only as a means to administer the surfactant. Current evidences suggest that this approach is feasible and should be started as soon as possible in the delivery room after stabilization. Several studies have been published based on the INSURE approach all consistently producing similar results. For instance, the administration of poractant-alfa with extubation to CPAP significantly reduced the need for mechanical ventilation when compared to a conventional treatment (43 vs 85%), requiring the study to be terminated early. Similar results were obtained in a similar trial looking at early vs late surfactant with CPAP: the early group had a significant reduction in the need for mechanical ventilation (21 vs 63%) and this study was also terminated early. These results were confirmed by a Cochrane Review evaluating the use of surfactant and rapid extubation to nasal CPAP, which indicated that infants with RDS treated with early surfactant replacement therapy and nasal CPAP were less likely to need mechanical ventilation and were at a lower risk for air leaks than infants treated with nasal CPAP and later surfactant therapy. On the other hand, while the Columbia approach gave promising preliminary results, its efficacy has not been confirmed in studies conducted in other centers than Columbia Hospital.
In conclusion, current evidence suggests the existence of a synergistic effect between early surfactant administration (within 2 h of birth) and rapid extubation to nasal CPAP, with a significant reduction in the need for mechanical ventilation and its associated morbidities. The recommended approach for LBW infants with RDS is therefore to start CPAP in the delivery room immediately after stabilization, with intubation only for surfactant administration. Mechanical ventilation should be utilized only if infants meet strict intubation criteria.

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