Randomised controlled trial of high frequency oscillation (HFO) vs conventional ventilation (CV): effects on extracellular volume (ECV) and fluid balance

Background. Higher mean airway pressures (MAD) are used in HFO(high volume strategy) than in CV. High MADs reduce cardiac output and diuresis. Hypothesis. HFO inhibits the postnatal decrease in ECV by reducing diuresis. Methods. Ventilated preterm infants (GA<30 wks) were randomised to HFO (Infant Star ™) or CV (Sechrist™ model IV-100B). We measured ECV (sucrose dilution), urine output, fluid intake and MAD. Results. HFO-infants had higher MADs for 24 hours (median 6.7 vs 3.7 cmH₂O; p=0.01). Postnatal urine output increased and ECV decreased in both groups. Conclusion. HFO did not prevent the postnatal adaptation of extracellular volume. Table

Table 1