What is the recommended treatment for Respiratory Distress Syndrome (RDS) using surfactant replacement therapy, such as poractant alfa (Curosurf)?

Surfactant Replacement Therapy for Respiratory Distress Syndrome

Preterm infants born at <30 weeks' gestation who need mechanical ventilation because of severe RDS should be given surfactant after initial stabilization, with poractant alfa (Curosurf) being an effective option for rescue treatment to reduce mortality and pneumothoraces. 1, 2

Treatment Algorithm for RDS

Initial Respiratory Support

• For spontaneously breathing preterm infants with respiratory distress, continuous positive airway pressure (CPAP) should be initiated immediately after birth as the first-line respiratory support 3
• Early initiation of CPAP with subsequent selective surfactant administration in extremely preterm infants results in lower rates of bronchopulmonary dysplasia (BPD)/death compared with prophylactic surfactant therapy 1, 3

Surfactant Administration Indications

• Preterm infants who develop worsening respiratory distress while on CPAP should receive selective surfactant administration 1
• Rescue surfactant may be considered for infants with hypoxic respiratory failure attributable to secondary surfactant deficiency (e.g., meconium aspiration syndrome, sepsis/pneumonia, pulmonary hemorrhage) 1

Dosing and Administration of Poractant Alfa (Curosurf)

• Initial recommended dose is 2.5 mL/kg birth weight 2
• Up to two repeat doses of 1.25 mL/kg birth weight may be administered at approximately 12-hour intervals 2
• Maximum total dose (initial plus repeat doses) is 5 mL/kg 2
• Administration should be done intratracheally either in two divided aliquots through a 5 French end-hole catheter or as a single bolus through secondary lumen of a dual lumen endotracheal tube 2

Evidence Supporting Surfactant Therapy

• Surfactant replacement therapy significantly reduces mortality (RR: 0.63), pneumothorax (RR: 0.62), and the combined outcome of bronchopulmonary dysplasia and death (RR: 0.85) in preterm infants with RDS 4
• Early rescue surfactant treatment (<2 hours of age) in infants with established RDS decreases the risk of mortality, air leak, and chronic lung disease compared to delayed administration 1, 4
• Both animal-derived and synthetic surfactants with SP-B-like activity decrease acute respiratory morbidity and mortality in preterm infants with RDS 1, 4

Comparative Efficacy of Surfactant Preparations

• Poractant alfa (Curosurf) at a higher initial dose of 200 mg/kg has been shown to result in faster reduction in supplemental oxygen requirements compared to beractant (Survanta) 5
• Treatment with poractant alfa (200 mg/kg initial dose) significantly reduced mortality compared to either beractant or poractant alfa at 100 mg/kg dosing in infants ≤32 weeks gestation with RDS 5, 6
• Natural surfactants derived from animal sources containing surfactant proteins B and C have shown better outcomes than synthetic surfactants without these proteins 6

Alternative Administration Techniques

• The INSURE technique (Intubation, Surfactant administration, and Extubation to CPAP) may be used for surfactant delivery to minimize time on mechanical ventilation 3, 7
• Less invasive surfactant administration via a thin endotracheal catheter without intubation has shown promising results with lower rates of mechanical ventilation and better pulmonary outcomes in some studies 7

Potential Complications and Monitoring

• Acute changes in lung compliance can occur after surfactant administration, requiring frequent assessment of oxygen and ventilatory support needs 2
• Administration-related adverse reactions may include bradycardia, hypotension, endotracheal tube blockage, and oxygen desaturation, which require stopping surfactant administration and taking appropriate measures 2
• Preterm and term neonates receiving surfactant should be managed by personnel with technical and clinical expertise to administer surfactant safely and manage multisystem illness 1

Synergy with Other Treatments

• Antenatal steroids and postnatal surfactant replacement independently and additively reduce mortality, severity of RDS, and air leaks in preterm infants 1, 4
• Antenatal steroids may reduce the need for prophylactic and early rescue surfactant replacement in infants born after 27-28 weeks' gestation 1, 4