Nasal high-frequency oscillatory ventilation and CO2 removal: A randomized controlled crossover trial

ObjectiveTo compare short-term application of nasal high-frequency oscillatory ventilation (nHFOV) with nasal continuous positive airway pressure (nCPAP). Working HypothesisnHFOV improves CO2 removal with respect to nCPAP in preterm infants needing noninvasive respiratory support and persistent oxygen supply after the first 72h of life. Study DesignMulticenter non-blinded prospective randomized crossover study. Patient SelectionThirty premature infants from eight tertiary neonatal intensive care units, of meanSD 26.41.8 weeks of gestational age and 921177g of birth weight. MethodologyInfants were randomly allocated in a 1:1 ratio to receive a starting treatment mode of either nCPAP or nHFOV delivered by the ventilator CNO (Medin, Germany), using short binasal prongs of appropriate size. A crossover design with four 1-h treatment periods was used, such that each infant received both treatments twice. The primary outcome was the mean transcutaneous partial pressure of CO2 (TcCO2) value during the 2-h cumulative period of nHFOV compared with the 2-h cumulative period of nCPAP. ResultsSignificantly lower TcCO2 values were observed during nHFOV compared with nCPAP: 47.5 +/- 7.6 versus 49.9 +/- 7.2mmHg, respectively, P=0.0007. A different TcCO2 behavior was found according to the random sequence: in patients starting on nCPAP, TcCO2 significantly decreased from 50.0 +/- 8.0 to 46.6 +/- 7.5mmHg during nHFOV (P=0.001). In patients starting on nHFOV, TcCO2 slightly increased from 48.5 +/- 7.8 to 49.9 +/- 6.7mmHg during nCPAP (P=0.13). ConclusionsnHFOV delivered through nasal prongs is more effective than nCPAP in improving the elimination of CO2.