Carbon dioxide clearance using bubble CPAP with superimposed high‐frequency oscillations in a premature infant lung model with abnormal lung mechanics

• Published in: Pediatric pulmonology 2020-11, Vol.55 (11), p.3189-3196
• Main Authors: Sivieri, Emidio M., Eichenwald, Eric C., Rub, David, Abbasi, Soraya
• Format: Article
• Language: English
• Subjects: airway resistance; Carbon dioxide; Carbon Dioxide - metabolism; CO2 clearance; Continuous Positive Airway Pressure; end‐tidal carbon dioxide; High-Frequency Ventilation; Humans; Infant, Newborn; Infant, Premature; Lung - metabolism; Lung - physiopathology; lung compliance; Mechanics; Models, Biological; noninvasive ventilation; Premature babies; Premature birth
• ISSN: 8755-6863; 1099-0496
• DOI: 10.1002/ppul.25040

Background High‐frequency (HF) oscillatory ventilation has been shown to improve carbon dioxide (CO2) clearance in premature infants. In a previous in vitro lung model with normal lung mechanics we demonstrated significantly improved CO2 washout by HF oscillation of bubble continuous positive airway pressure (BCPAP). Objective To examine CO2 clearance in a premature infant lung model with abnormal lung mechanics via measurement of end‐tidal CO2 levels (EtCO2) while connected to HF oscillated BCPAP. Design and Methods A 40 mL premature infant lung model with either: normal lung mechanics (NLM): compliance 1.0 mL/cm H2O, airway resistance 56 cm H2O/(L/s); or abnormal lung mechanics (ALM): compliance 0.5 mL/cm H2O, airway resistance 136 cm H2O/(L/s), was connected to BCPAP with HF oscillation at either 4, 6, 8, 10, or 12 Hz. EtCO2 was measured at BCPAPs of 4, 6, and 8 cm H2O and respiratory rates (RR) of 40, 60, and 80 breaths/min and 6 mL tidal volume. Results HF oscillation decreased EtCO2 levels at all BCPAPs, RRs, and oscillation frequencies for both lung models. Overall mean ± SD EtCO2 levels decreased (P