Bubble continuous positive airway pressure (B-CPAP) applies small-amplitude, high-frequency oscillations in airway pressure (ΔPaw) that may improve gas exchange in infants with respiratory disease. We developed a device, high-amplitude B-CPAP (HAB-CPAP), which provides greater ΔPaw than B-CPAP provides. We studied the effects of different operational parameters on ΔPaw and volumes of gas delivered to a mechanical infant lung model. In vivo studies tested the hypothesis that HAB-CPAP provides noninvasive respiratory support greater than that provided by B-CPAP. Lavaged juvenile rabbits were stabilized on ventilator nasal CPAP. The animals were then supported at the same mean airway pressure, bias flow, and fraction of inspired oxygen (FiO2) required for stabilization, whereas the bubbler angle was varied in a randomized crossover design at exit angles, relative to vertical, of 0 (HAB-CPAP0; equivalent to conventional B-CPAP), 90 (HAB-CPAP90), and 135° (HAB-CPAP135). Arterial blood gases and pressure-rate product (PRP) were measured after 15 min at each bubbler angle. Pao2 levels were higher (p 2 levels did not differ (p = 0.073) among the three bubbler configurations. PRP with HAB-CPAP135 were half of the PRP with HAB-CPAP0 or HAB-CPAP90 (p = 0.001). These results indicate that HAB-CPAP135 provides greater respiratory support than conventional B-CPAP does.Abbreviations: ΔPaw, oscillations in airway pressure; ΔV, oscillations in volume; ABG, arterial blood gas analysis(es); B-CPAP, bubble CPAP; CPAP, continuous positive airway pressure; FiO2, fraction of inspired oxygen; HAB-CPAP, high-amplitude B-CPAP; HFOV, high-frequency oscillatory ventilation; MAP, mean airway pressure; Paw, airway pressure; Pes, esophageal pressure; PRP, pressure rate product(s); SpO2, pulse oximeter oxygen saturation(s); WOB, work of breathing
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