High Frequency Partial Liquid Ventilation vs. Infasurf Rescue in Preterm Lambs with Respiratory Distress Syndrome (RDS) † 1720

Surfactant replacement therapy is established as a primary treatment for RDS in preterm infants. Its efficacy however, is decreased in advanced disease states. Partial liquid ventilation (PLV) with perflubron (LiquiVentr) appears to improve lung function in infants with RDS who have failed to respond to exogenous surfactant. We hypothesized that PLV alone would improve lung function as compared with exogenous surfactant (Infasurfr) in the rescue treatment of severe RDS. We studied preterm lambs delivered by C-section(gest. age 125-127 days) with severe advanced RDS (criteria: P_aO₂ 20-40 mmHg at 3 hours of life). Lambs were placed on high frequency ventilation (Sensormedics 3100A) with F₁O₂ 1.0, amplitude 50 cmH₂O, frequency 8-10 Hz, and mean airway pressure 15 cmH₂O. At 3 h, animals received either Infasurf (100 mg/kg) or PLV with LiquiVent (25 ml/kg initial dose with replacement of evaporative losses).Results: P_aO₂ was increased 2.5-fold within 30 minutes in the LiquiVent group, and this improvement was sustained for the two hours of study. In contrast, the Infasurf group showed minimal response in P_aO₂, and this value returned to pretreatment baseline by 2 hours. P_aCO₂ trended downward with PLV (P_aCO₂: 70± 10 mmHg to 54 ± 7 mmHg) as compared with Infasurf(P_aCO₂: 69 ± 7 mmHg to 65 ± 8 mmHg). Necropsy revealed hemorrhagic, edematous lungs in the Infasurf group and less diffuse and less severe changes in the LiquiVent group. We conclude that PLV with LiquiVent is more effective than Infasurf in the treatment of severe, advanced RDS in the preterm lamb. PLV may be useful as a primary intervention in infants with severe advanced RDS. Figure

Figure 1