Comparison of high-frequency flow interruption ventilation and hyperventilation in persistent pulmonary hypertension of the newborn.

INTRODUCTION: Because of the high mortality, potential limitations, and inherent adverse effects associated with conventional therapies, as well as extracorporeal membrane oxygenation, for persistent pulmonary hypertension of the newborn (PPHN), alternative modes of ventilatory support have been researched. There is anecdotal evidence that high-frequency flow interruption ventilation (HFFI) benefits neonates with severe air leak and lung diseases unresponsive to conventional ventilation, so we conducted a study to compare the hospital course, survival rate, and incidence of chronic lung disease of neonates with PPHN treated with hyperventilation (HV) and HFFI. METHODS: Enrolled in the study were 36 neonates who (1) were treated with HV and a fraction of inspired oxygen of 1.0 for PPHN, (2) had arterial partial pressure of oxygen (P(aO2)) values or= 120 mm Hg; (3) shorter mean time to P(aO2) >or= 120 mm Hg (13.5 vs 50.2 h, p = 0.001); (4) shorter mean time to reduced fraction of inspired oxygen (16 vs 84 h, p < 0.001); (5) shorter mean time to fraction of inspired oxygen 0.70 (53 vs 187 h, p < 0.001); (6) shorter mean time to extubation (8.1 vs 18.7 d, p = 0.033); (7) shorter length of hospitalization (22.7 vs 50.6 d, p = 0.025); and (8) fewer neonates with chronic lung disease (1 vs 5, p = 0.018). CONCLUSIONS: HFFI with the ventilation strategy we describe accomplishes sustained hyperoxygenation without hypocarbia and alkalosis, and response to HFFI can predict outcomes. HFFI does not significantly reduce mortality, but it does reduce the length of mechanical ventilation, the length of hospitalization, and the incidence of chronic lung disease in neonates with PPHN. The nonrandomized design of our study precludes firm conclusions about the potential benefits of HFFI. The results may be biased by practice variations. Additional randomized controlled trials are warranted to determine the efficacy of HFFI in neonates with PPHN.

The effect of vertical pulsating stimulation on apnea of prematurity.

Placing preterm infants suffering idiopathic apnea of prematurity on the VPS had an effect on the infants' respiratory effort and achieved a reduction in the number of apneic episodes secondary to central and mixed apnea. However, VPS offered no benefits in the reduction of obstructive apnea in this study population. Because central apnea has been reported as the predominant type of apnea and VPS is a nontoxic, noninvasive, and easy-to-implement method of alleviating central and mixed apnea types, it seems prudent to give VPS which has the stimulus characteristics to preterm infants experiencing apnea of prematurity before other treatment modalities currently in use are tried. Further studies are warranted to determine if VPS is effective in a continuous long-term treatment for apnea of prematurity, for example, until the end of apnea.

High-frequency flow interruption in the rescue of preterm infants with severe RDS.

High-frequency flow interruption (HFFI) was used successfully to rescue three preterm infants with severe respiratory distress syndrome (RDS) whose clinical condition continued to deteriorate while on the conventional mechanical ventilation. Had the HFFI not been used, the survival chances might have been 25 per cent for Case 1 and 2, and 45.5 per cent for Case 3. A dramatic, immediate, and sustained improvement in ventilation and oxygenation was demonstrated once the critical frequency and amplitude of HFFI were established. Bronchopulmonary dysplasia which was already evidenced in one infant before the HFFI attempt was detected in two infants. This study demonstrates that HFFI is capable of achieving adequate gas exchange and improving survival in infants with severe RDS.