The sy-fi study: a randomized prospective trial of synchronized intermittent mandatory ventilation versus a high-frequency flow interrupter in infants less than 1000 g

J Perinatol. 2003 Jan;23(1):14-9. doi: 10.1038/


Objective: Mechanical ventilation has significantly decreased mortality for preterm infants with respiratory distress syndrome. However, the barotrauma associated with mechanical ventilation is responsible for the development of bronchopulmonary dysplasia (BPD) in 20% to 90% of these infants, depending on gestational age. Recent studies suggest that high-frequency ventilation is associated with better gas exchange and less barotrauma. The purpose of this study is to determine if high-frequency ventilation, using the flow interrupter, reduces the incidence of BPD in the ELBW infant.

Study design: Parental consent was obtained prior to mechanical ventilation. Infants less than 1000 g without significant congenital anomalies were eligible for study entry. Infants were randomized, prior to the onset of mechanical ventilation, to receive either synchronized intermittent mandatory ventilation (SIMV) or high-frequency flow interruption. Both ventilator methods were obtained using the Infant Star Ventilator (Mallinckrodt, St. Louis, MO). Data were collected prospectively on all study entrants and analyzed using SigmaStat Software.

Results: Forty-six infants, from two centers, were enrolled in this study. There was no significant difference in the ventilator days or BPD, defined as oxygen requirement at 36 weeks postmenstrual age, between the high-frequency ventilation and SIMV groups.

Publication types

  • Clinical Trial
  • Multicenter Study
  • Randomized Controlled Trial

MeSH terms

  • Bronchopulmonary Dysplasia / prevention & control*
  • Female
  • High-Frequency Ventilation*
  • Humans
  • Infant, Newborn
  • Infant, Very Low Birth Weight
  • Intermittent Positive-Pressure Ventilation*
  • Male
  • Prospective Studies
  • Respiratory Distress Syndrome, Newborn / therapy*