Late Breaking Abstract - In-vitro evaluation of a neonatal adaptation of an adult oscillometer for respiratory mechanics assessment

<bold>Aim:</bold> Respiratory oscillometry assesses respiratory mechanics independently of patient efforts. Existing commercially-available oscillometry devices are designed for children aged > 3yrs, preventing their use in neonatal care. We aimed to evaluate the in-vitro accuracy of a novel oscillometer that addresses specific neonatal requirements such as very low dead space and highly accurate flow sensing. <bold>Methods:</bold> A Resmon PRO FULL oscillometer (RESTECH Srl) was modified by connecting a breathing circuit tube, an intentional leak, proximal flow and pressure sensor and a neonatal face mask to the device patient connector, resulting in a dead space <1.5 ml/kg with a bias flow of 8 L/min for CO2 washout. An active test lung made of mesh-type resistors (15, 25, and 40 cmH2Os/l) to simulate airway resistance (Rrs) and acrylic glass cylinders (0.5, 1.0, and 3 L) to simulate reactance (Xrs) was configured to replicate spontaneous neonatal breathing patterns. Measured respiratory impedance at 8 and 10 Hz were compared with theoretical values (Franken et al., 1981). <bold>Results:</bold> Rrs and Xrs at 8 and 10 Hz closely matched expected values, as for breathing pattern metrics, with measurements errors staying within the recommended limits (Table). <bold>Conclusion:</bold> The modified oscillometer accurately measures respiratory impedance and breathing pattern indexes in in-vitro models of infants from 2.5 kg to approximately three years old. <fig><object-id>erj;64/suppl_68/PA4086/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig>