BACKGROUND: High frequency oscillation (HFO) is now frequently used as rescue support, but it has been suggested that as many as one-third of survivors have abnormal neurodevelopmental findings at follow-up. OBJECTIVE: To identify risk factors for adverse neurodevelopmental outcome at 1 and 2 years in very prematurely born patients, who, because of severe neonatal respiratory failure, had required transfer to high frequency oscillation (HFO). METHODS: A case control study was performed. Controls were supported by conventional mechanical ventilation (CMV) only and matched to HFO infants for gestational age. At 1 and 2 years, neurodevelopmental status was assessed in both groups. Abnormal neurodevelopmental outcome was diagnosed if infants had impairment with or without disability or a Griffiths developmental quotient of at least two standard deviations below the mean. PATIENTS: Fifty-six infants were studied, median gestation age of 28 weeks (range 23--31). RESULTS: At 2 years of age, a greater proportion of the HFO infants compared to the controls had an abnormal outcome (p<0.05). HFO infants with an abnormal outcome compared to those with a normal outcome had poorer oxygenation prior to transfer to HFO (p=0.05), but did not have a lower initial improvement in oxygenation or longer duration of hypocarbia on HFO. Logistic regression demonstrated adverse outcomes significantly related to HFO use and gestational age in the whole study population and to gestational age in the HFO infants. CONCLUSION: An initial response to HFO does not guarantee normal neurodevelopmental outcome. Rescue HFO in very immature infants should be used cautiously.
BACKGROUND: High frequency oscillation (HFO) is now frequently used as rescue support, but it has been suggested that as many as one-third of survivors have abnormal neurodevelopmental findings at follow-up. OBJECTIVE: To identify risk factors for adverse neurodevelopmental outcome at 1 and 2 years in very prematurely born patients, who, because of severe neonatal respiratory failure, had required transfer to high frequency oscillation (HFO). METHODS: A case control study was performed. Controls were supported by conventional mechanical ventilation (CMV) only and matched to HFO infants for gestational age. At 1 and 2 years, neurodevelopmental status was assessed in both groups. Abnormal neurodevelopmental outcome was diagnosed if infants had impairment with or without disability or a Griffiths developmental quotient of at least two standard deviations below the mean. PATIENTS: Fifty-six infants were studied, median gestation age of 28 weeks (range 23--31). RESULTS: At 2 years of age, a greater proportion of the HFO infants compared to the controls had an abnormal outcome (p<0.05). HFO infants with an abnormal outcome compared to those with a normal outcome had poorer oxygenation prior to transfer to HFO (p=0.05), but did not have a lower initial improvement in oxygenation or longer duration of hypocarbia on HFO. Logistic regression demonstrated adverse outcomes significantly related to HFO use and gestational age in the whole study population and to gestational age in the HFO infants. CONCLUSION: An initial response to HFO does not guarantee normal neurodevelopmental outcome. Rescue HFO in very immature infants should be used cautiously.