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

Objective: To compare short-term application of nasal high-frequency oscillatory ventilation (nHFOV) with nasal continuous positive airway pressure (nCPAP). Working Hypothesis: nHFOV improves CO2 removal with respect to nCPAP in preterm infants needing noninvasive respiratory support and persistent oxygen supply after the first 72 h of life. Study Design: Multicenter non-blinded prospective randomized crossover study. Patient Selection: Thirty premature infants from eight tertiary neonatal intensive care units, of mean ± SD 26.4 ± 1.8 weeks of gestational age and 921 ± 177 g of birth weight. Methodology: Infants 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. Results: Significantly lower TcCO2 values were observed during nHFOV compared with nCPAP: 47.5 ± 7.6 versus 49.9 ± 7.2 mmHg, 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 ± 7.5 mmHg during nHFOV (P = 0.001). In patients starting on nHFOV, TcCO2 slightly increased from 48.5 ± 7.8 to 49.9 ± 6.7 mmHg during nCPAP (P = 0.13). Conclusions: nHFOV delivered through nasal prongs is more effective than nCPAP in improving the elimination of CO2.