High-frequency oscillatory ventilation in pediatric patientsIntroduction: High-frequency oscillatory ventilation (HFOV) uses small tidal volumes, often smaller than the anatomic dead space, with high respiratory rates (> 1 Hz).This therapeutic option has become more popular in our country in the last years.Study objectives: To review the clinical experience with HFOV in our Pediatric Intensive Care Unit and to describe the patient's characteristics, HFOV strategies and outcome.Patients: A prospective study included patients less than 16 years old with Acute Respiratory Distress Syndrome (ARDS) refractary to conventional mechanical ventilation (CMV).We compare two periods (1999-2001 and 2002-2004).Measurements and results: Forty-nine patients underwent onto 51 episodes of HFO ventilation, 80% presented with primary ARDS.Previous conventional ventilation was 47 hours long.The median value of the oxygenation index (OI) at the beginning of HFOV was 24.Mean airway pressure was initially set at 9 cmH 2 O above the value in conventional ventilation.All the patients presented a decrease of their OI and ventilation was improved during the first 48 hours of therapy.Median duration on HFOV was 102 hours.The most frequent side effect was transient hypotension (25%).In the second period we observed a decrease in hemodynamic complications and also an increase in HFO duration.The mortality rate was 33% (22% due to pulmonary cause).Conclusion: HFOV is an effective therapy for pediatric respiratory failure refractory to conventional mechanical ventilation.