Surfactant Administration in Respiratory Distress Syndrome
Direct Recommendation
Administer animal-derived surfactant (poractant alfa or beractant) as early rescue therapy within 1-2 hours of birth to preterm infants with established RDS who require mechanical ventilation, or use the INSURE technique (Intubation-Surfactant-Extubation to CPAP) for those initially managed with CPAP who show worsening respiratory distress. 1
Indications for Surfactant Therapy
Primary Indication: Preterm Infants with RDS
Preterm infants <30 weeks' gestation requiring mechanical ventilation due to severe RDS should receive surfactant after initial stabilization. 1, 2 The evidence is strongest for this population, where surfactant therapy reduces mortality (RR 0.63; 95% CI 0.47-0.84), pneumothorax (RR 0.62; 95% CI 0.42-0.89), and the combined outcome of bronchopulmonary dysplasia or death (RR 0.85; 95% CI 0.76-0.95). 3
Timing Strategy: Early Rescue vs Prophylactic
Early rescue surfactant administered within 1-2 hours of birth is superior to delayed treatment (≥2 hours), significantly decreasing mortality (RR 0.84; 95% CI 0.74-0.95), air leak (RR 0.61; 95% CI 0.48-0.78), and chronic lung disease (RR 0.69; 95% CI 0.55-0.86). 1
Prophylactic surfactant (within 10-30 minutes after birth) is no longer routinely recommended as first-line therapy, as the benefits are no longer evident when CPAP is used routinely. 4, 3 However, prophylactic surfactant may still benefit extremely preterm infants at highest risk of RDS, particularly those without antenatal steroid exposure. 3
Secondary Indications: Term and Late-Preterm Infants
Surfactant therapy may benefit late-preterm and term neonates with secondary surfactant deficiency from meconium aspiration syndrome, pneumonia/sepsis, and pulmonary hemorrhage. 1 For meconium aspiration syndrome specifically, surfactant improves oxygenation and reduces ECMO requirements. 1, 5
Do not use surfactant for infants with congenital diaphragmatic hernia, as it has not shown improved outcomes. 1, 3
Modes of Administration
CPAP-First Strategy with Selective Surfactant
Initiate CPAP at 5-6 cm H₂O immediately after birth for spontaneously breathing preterm infants with respiratory distress, then administer surfactant selectively if respiratory distress worsens. 1, 2 This approach results in lower rates of bronchopulmonary dysplasia and death compared to prophylactic surfactant therapy (RR 0.53; 95% CI 0.34-0.83). 1, 2
INSURE Technique
The INSURE strategy (Intubation, Surfactant administration, and Extubation to CPAP) significantly reduces the need for mechanical ventilation (RR 0.67; 95% CI 0.57-0.79) and oxygen requirement at 28 days. 1 This technique involves:
- Brief intubation for surfactant delivery
- Immediate extubation to CPAP support
- Avoidance of prolonged mechanical ventilation 1, 2
Traditional Endotracheal Administration
Surfactant is administered through an endotracheal tube either as a bolus, in smaller aliquots, or by infusion. 1 The optimal method remains unclear, as clinical trials show no significant differences in outcomes between bolus and infusion techniques. 1
Surfactant Preparation Selection
Animal-derived surfactants (poractant alfa, beractant, calfactant) are superior to first-generation synthetic surfactants, demonstrating lower mortality rates (RR 0.86; 95% CI 0.76-0.98) and fewer pneumothoraces (RR 0.63; 95% CI 0.53-0.75). 1, 3 Poractant alfa shows advantages over beractant in reducing mortality, need for repeat dosing, and faster extubation. 1
Dosing and Redosing Strategy
Plan for up to 3 additional doses in the first 48 hours if the infant continues to require mechanical ventilation with FiO₂ ≥0.30. 1 Administer doses no more frequently than every 12 hours unless surfactant is being inactivated by infection, meconium, or blood. 1 Pneumonia and infection can inactivate surfactant, potentially requiring more frequent redosing than the typical 12-hour interval. 1
Critical Monitoring and Adjustments
Surfactant administration may cause transient airway obstruction, oxygen desaturation, bradycardia, and alterations in cerebral blood flow. 1 Expeditious changes in ventilator settings may be necessary after surfactant administration to minimize lung injury and air leak. 1
Reduce ventilator pressures and FiO₂ promptly after surfactant administration as lung compliance improves to prevent volutrauma and oxygen toxicity. 1
Personnel Requirements
Surfactant must be administered by or under supervision of clinicians experienced in intubation, ventilator management, and general care of premature infants. 1, 3
Synergy with Antenatal Steroids
Antenatal steroids and postnatal surfactant work independently and additively, reducing mortality, severity of RDS, and air leaks more than either alone. 1, 3 This synergistic effect underscores the importance of antenatal steroid administration when preterm delivery is anticipated, but surfactant should still be administered regardless of antenatal steroid exposure. 3
Common Pitfalls to Avoid
- Delaying surfactant administration beyond 2 hours in infants with established RDS requiring mechanical ventilation 1
- Routine intubation with prophylactic surfactant without a trial of CPAP in spontaneously breathing preterm infants 1, 2
- Administering surfactant to infants with mild to moderate RDS not requiring mechanical ventilation (birth weight ≥1250 grams), as this does not improve outcomes and increases duration of mechanical ventilation 6
- Failing to reduce ventilator settings promptly after surfactant administration, risking lung injury from improved compliance 1
- Using surfactant for congenital diaphragmatic hernia, where it is ineffective 1, 3