NEW YORK (Reuters Health) – In very low birthweight infants with apnea of prematurity, a variable flow ventilator may be more effective for respiratory support than a conventional ventilator, according to German researchers.

Dr. Christian F. Poets, of University Children’s Hospital Tuebingen, and colleagues conducted a randomized crossover trial in 16 neonates with apnea of prematurity. Each baby was treated for 6 hours with four different modes of support: nasal intermittent positive pressure ventilation (NIPPV) via a conventional device, NIPPV via a variable flow device, nasal continuous positive airway pressure (NCPAP) via the variable flow device, and NCPAP via a constant flow underwater bubble system.

In all cases, variable flow ventilation was nonsynchronized, according to the standard practice in the authors’ neonatal intensive care unit.

In the July Archives of Disease in Childhood Fetal & Neonatal Edition, the investigators report that the median cumulative event rate of bradycardias and desaturation episodes was “6.7 per hour with the conventional ventilator in NIPPV mode, and 2.8 and 4.4 per hour with the variable flow device in NCPAP and NIPPV mode, respectively (p value <0.03 for both compared to NIPPV/conventional ventilator).” There were no significant differences between NIPPV with the conventional ventilator and NCPAP with the underwater bubble system. Because the inclusion criteria for the study required that the infants not need supplemental oxygen, patient recruitment took longer than expected, and the researchers terminated the study after accrual of only these 16 subjects. “Due to this decrease in sample size, statistical power was likely lost for some comparisons,” the researchers write. “We therefore…compared only the conventional ventilator in NIPPV mode with the other three test devices.” Still, they conclude, “This study has shown marked differences in the effect of four nasal respiratory support systems on symptoms of apnea of prematurity. “Further studies are necessary to investigate whether synchronized NIPPV performs even better,” they add. Reference:
Arch Dis Child Fetal Neonatal Ed 2009:94:F245-F248.