title: Late administration of surfactant replacement therapy increases surfactant protein-B content: a randomized pilot study.
abstract: BACKGROUND
  Surfactant dysfunction may contribute to the development of bronchopulmonary dysplasia (BPD) in persistently ventilated preterm infants. We conducted a multicenter randomized, blinded, pilot study to assess the safety and efficacy of late administration of doses of a surfactant protein-B (SP-B)-containing surfactant (calfactant) in combination with prolonged inhaled nitric oxide (iNO) in infants ≤1,000 g birth weight (BW).
  
  
  METHODS
  We randomized 85 preterm infants ventilated at 7-14 d after birth to receive either late administration of surfactant (up to 5 doses) plus prolonged iNO or iNO alone. Large aggregate surfactant was isolated from daily tracheal aspirates (TAs) for measurement of SP-B content, total protein, and phospholipid (PL).
  
  
  RESULTS
  Late administration of surfactant had minimal acute adverse effects. Clinical status as well as surfactant recovery and SP-B content in tracheal aspirate were transiently improved as compared to the controls; these effects waned after 1 d. The change in SP-B content with surfactant dosing was positively correlated with SP-B levels during treatment (r = 0.50, P = 0.02).
  
  
  CONCLUSIONS
  Low SP-B values increased with calfactant administration, but the relationship of this response to SP-B levels suggests that degradation is a contributing mechanism for SP-B deficiency and surfactant dysfunction. We conclude that late therapy with surfactant in combination with iNO is safe and transiently increases surfactant SP-B content, possibly leading to improved short- and long-term respiratory outcomes.
authors.affiliation: Department of Pediatrics, University of California, San Francisco, San Francisco, California, USA. kellerr@peds.ucsf.edu
authors.forename: Roberta L
authors.initials: RL
authors.lastname: Keller
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Merrill
authors.forename: Dennis M
authors.initials: DM
authors.lastname: Black
authors.forename: Robin H
authors.initials: RH
authors.lastname: Steinhorn
authors.forename: Eric C
authors.initials: EC
authors.lastname: Eichenwald
authors.forename: David J
authors.initials: DJ
authors.lastname: Durand
authors.forename: Rita M
authors.initials: RM
authors.lastname: Ryan
authors.forename: William E
authors.initials: WE
authors.lastname: Truog
authors.forename: Sherry E
authors.initials: SE
authors.lastname: Courtney
authors.forename: Philip L
authors.initials: PL
authors.lastname: Ballard
authors.forename: Roberta A
authors.initials: RA
authors.lastname: Ballard
mesh_terms: D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D010865:Pilot Projects; D037701:Pulmonary Surfactant-Associated Protein B / Q000172:deficiency*; D011663:Pulmonary Surfactants / Q000008:administration & dosage*
chemical_list: D037701:Pulmonary Surfactant-Associated Protein B; D011663:Pulmonary Surfactants