Supplementary Material for: Comparison of Bubble CPAP Devices Using RAM Cannula for Extubation Failure in Very Low Birth Weight Infants: Randomized and Cohort Studies

<b><i>Introduction:</i></b> Bubble continuous positive airway pressure (bCPAP) generates a variable pressure due to bubble size and frequency, and these pressure oscillations may contribute to lung recruitment and gas exchange. Single-outlet bCPAP devices generate larger pressure fluctuation than bCPAP devices with diffusers, but clinical efficacy is unclear. Our hypothesis was that a single-outlet bCPAP device (B&B Bubbler<sup>©</sup>) would decrease extubation failure and improve oxygenation compared with a bCPAP device with a diffuser (BabiPlus<sup>©</sup>). <b><i>Methods:</i></b> Bench testing of bCPAP devices with the RAM<sup>©</sup> cannula determined pressure averages, fluctuations, and CPAP transmission at prongs. The B&B Bubbler<sup>©</sup> and the BabiPlus<sup>©</sup> devices were compared for oxygenation and bCPAP failure within 72 h of extubation in a randomized trial in infants less than 1,250 g (<i>n</i> = 43). Additionally, a cohort study with infants extubated to BabiPlus<sup>©</sup> (<i>n</i> = 128), B&B Bubbler<sup>©</sup> (<i>n</i> = 119), and noninvasive positive pressure ventilation (NIPPV) (<i>n</i> = 107) were compared. <b><i>Results:</i></b> Small differences in pressure fluctuations between bCPAP devices are attenuated by the RAM<sup>©</sup> cannula. Pressures at RAM<sup>©</sup> prongs are 62% of set pressure. The bCPAP extubation failure rate (35%) and oxygenation were similar between the bCPAP devices. bCPAP success was associated with lower FiO<sub>2</sub> at extubation and decreased need for additional FiO<sub>2</sub> in both groups. In the setting of the RAM<sup>©</sup> cannula, there were no differences in extubation failure rate for infants extubated to bCPAP or NIPPV. <b><i>Conclusions:</i></b> There were no clinical differences at extubation between the B&B Bubbler<sup>©</sup> and BabiPlus<sup>©</sup> devices. Oxygenation may predict bCPAP failure. The use of the RAM<sup>©</sup> cannula as a bCPAP interface should be more closely examined.