Trends in use and outcome of newborn infants treated with high frequency ventilation in Australia and New Zealand, 1996–2003

Aim:  To examine the use of high frequency ventilation (HFV) to treat newborn infants in Australia and New Zealand and the associated complications and outcomes. Methods:  Data for all infants receiving HFV were collected from the 28 neonatal intensive care units contributing to the Australian and New Zealand Neonatal Network database between 1996 and 2003, inclusive. For comparison, the same data were gathered on all infants who received conventional mechanical ventilation (CMV) and nasal continuous positive airway pressure. Results:  HFV was used to treat 3270 infants (10.1% of all ventilated infants) between 1996 and 2003; uptake doubled during this period from 5.9% to 12.6% of ventilated infants per year. HFV was most frequently applied in the context of extreme prematurity (29.9% of ventilated infants <26 weeks gestation). HFV is being increasingly used to treat complex diseases such as meconium aspiration syndrome and congenital diaphragmatic hernia (12.2% and 10.6% in 1996 to 25.2% and 48.4% in 2003, respectively, χ2-test for trend, P < 0.001). Infants receiving HFV spent longer on respiratory support than infants treated with CMV (median 21 days compared with 7 days, Mann–Whitney test P < 0.001) and required a higher initial FiO2 (median 0.8 compared to 0.5, Mann–Whitney test, P < 0.001). The use of HFV was associated with a higher mortality than CMV and nasal continuous positive airway pressure (39.7%, 10.1% and 0.4%, χ2-test, P < 0.001). The incidence of death and intraventricular haemorrhage decreased over time in the HFV group (χ2-test for trend, P < 0.001 and P = 0.02 respectively). Conclusion:  HFV is an established mode of neonatal ventilation in Australia and New Zealand. HFV is being applied to infants at the greatest risk of serious adverse outcomes, most likely as a rescue therapy.