Jonathan M. Klein, MD
Peer Review Status: Internally Peer Reviewed


A. Treatment of intubated infants on 30% or more oxygen whose clinical presentation and chest x-ray are consistent with RDS.

B. Prophylactic administration may be considered in infants < 26 weeks EGA.

C. Secondary surfactant dysfunction, inactivation or post surfactant slump.

Dosing Guidelines for Surfactant Replacement Therapy in the NICU
Description Surfactant
Premature infants with RDS  < 700 g Survanta
Premature infants with RDS > 700 g Curosurf
Premature infants unresponsive to 2 doses of Survanta Infasurf
Premature infants unresponsive to 2 doses of Curosurf  Infasurf
Premature infants with inactivation, dysfunction or post surfactant slump Infasurf
Term infants with surfactant inactivation or dysfunction Infasurf

Etiology of surfactant inactivation or dysfunction: pulmonary hemorrhage, sepsis, pneumonia, meconium aspiration, and post surfactant slump.

Surfactant replacement therapy for RDS - Early rescue therapy should be practiced: First dose needs to be given as soon as diagnosis of RDS is made. RDS in a premature infant is defined as respiratory distress requiring more than 30% oxygen delivered by positive pressure using either Nasal CPAP or an ET Tube with a chest radiograph that has diffuse infiltrates with a ground glass granular appearance with air bronchograms.  Ideally the dose should be given within 1 hr of birth but definitely before 2 hours of age.  A repeat dose should be given within 4 - 12 hours if the patient is still intubated and requiring more than 30 to 40% oxygen.

Prophylactic therapy (before chest radiograph) can be considered in patients with respiratory distress who are intubated and are < 26 weeks gestation.

Dosing Guidelines in the NICU
Dosing Description
Survanta 4 ml/kg in 4 aliquots, repeat dose as needed if responsive
Infasurf 3 ml/kg in 2 aliquots, repeat dose as needed, (use of "drip dosing on HFOV" discuss with staff/fellow)
Curosurf 2.5 ml/kg in 2 aliquots, repeat dose (1.25 ml/kg) as needed, (use of "in and out therapy" - rapid extubation after one dose, discuss with staff/fellow)

Subsequent doses are generally withheld if the infant requires less than 30% oxygen. The technical details of administration are discussed in the package insert and in the NICU Nursing Protocols on administration.

Ventilator Management:  A blood gas should be checked within 15 - 20 minutes of the dose and the ventilator settings should be weaned appropriately to minimize the risk of a pneumothorax. A chest radiograph should be checked both 1 hour and 4 - 6 hours after the initial dose to avoid hyperinflation.

Surveillance after administration

The clinical response is unpredictable. Lung compliance usually improves, sometimes quite rapidly. Blood gases should be monitored frequently, and the ventilator should be adjusted to keep the PCO2 above 40. Occasionally, gas exchange deteriorates after surfactant administration, requiring a temporary increase in settings to facilitate spreading or suctioning if the ET tube is becoming obstructed. In either case, close surveillance of chest wall movement and frequent monitoring of blood gases, especially during the first 3 hours after dosing, will minimize the complications of either volutrauma or atelectasis.


  1. Prophylactic vs Rescue - Dunn et al, Pediatrics 1991;87:377, Kendig et al. N Engl J Med 1991;324:865, Osiris Exosurf Trial - Lancet 1992
  2. Surfactant Inactivation – Hall et al, Am Rev Respir Dis, 1992;145:24, Seeger et al, Eur Respir J, 1993:6:971
  3. Survanta vs Infasurf - Bloom et al, Pediatrics 1997;100:31
  4. Survanta vs Curosurf - Ramanathan et al, Am J Perinatal 2004;21:109
  5. Term Infants - Findlay et al, Pediatrics 1996;97:48. Lotze et al, J Pediatr 1998;132:40
  6. Post Surfactant Slump - Katz and Klein, Journal of Perinatology 2006;26:414