Radiological Changes Following High Frequency Oscillatory Ventilation Therapy in Very Low Birth Weight Infants with Respiratory Distress Syndrome

ABSTRACT

PURPOSE: High frequency oscillatory ventilation (HFOV) is used to support infants with severe respiratory failure unresponsive to conventional ventilation (CV). We reviewed chest radiographs before and after HFOV with clinical correlation in infants with respiratory distress syndrome (RDS). METHODS: Eighteen very low birth weight infants with RDS who had HFOV were included in this study. All patients were diagnosed as having RDS clinically and radiologically. Mean gestational age of infants was 27 weeks (range 24-31 weeks). The mean duration of HFOV was 3 days (range 14 hours-9 days). The chest radiographs of these infants within 3 hours before and after application of HFOV were retrospectively reviewed. Radiological findings based on aeration and parenchymal densities were classified into improved, no change, and progressed. Medical records were reviewed for FiO2 levels, clinical outcomes, complications, and causes of death. RESULTS: In 15 of 18 infants, aeration and parenchymal densities were improved and FiO2 levels were also improved after HFOV. Four of these 15 infants who showed improvement of radiological findings developed pneumothorax, sepsis, pulmonary or intestinal bleeding, and subsequently died. In remaining 3 infants in whom chest radiographs after HFOV showed no interval change or progression, oxygenation was also worsened and all died. CONCLUSION: Chest radiographs of HFOV-treated, very low birth weight infants showed improvement of aeration and parenchymal densities in most cases. Clinical outcome was good in infants who showed improvement on chest radiographs compared to those of progression group as far as there was no associated complication. Knowledge of radiological changes after HFOV will help in interpretation of chest radiographs in those HFOV-treated infants.