1719 HUMAN SURFACTANT: A THERAPEUTIC TRIAL IN PREMATURE RABBITS

Abstract

The ability of human surfactant (HS) isolated by differential & density gradient centrifugation from amniotic fluid to alter pulmonary pressure-volume (P/V) loops in 27-day surfactant deficient fetal rabbits was evaluated. Fetuses were delivered & allowed to breathe spontaneously. Either 2 μmoles of HS in .Icc 0.6% NaCl, or similarly prepared rabbit surfactant (RS), or saline (controls) was applied endotracheally by tracheostomy. Fetuses were mechanically ventilated 15 min. sacrificed, & lungs degassed 15 min. at -20 cmH2O. Static, first cycle pulmonary P/V loops were measured by syringe & H2O manometer. Inflation & deflation volumes were recorded at 0,2,5,10,15,20,25, & 30 cmH2O: There were no significant differences between HS and RS. Histology revealed good homogeneous aeration in HS and RS fetuses and poor aeration in controls. HS markedly improved P/V loops in 27 day fetal rabbits and was comparable to RS. HS may be effective in treating RDS once its safety is established.