2024/02/28 by Kaoru Okazaki, Jumpei Kuroda
paper · doi:10.4187/respcare.10773
crossref created 2023/10/31 · crossref issued 2024/02/28 · crossref published 2024/02/28 · crossref published-online 2024/02/28 · crossref published-print 2024/03/01 · crossref deposited 2026/04/06 · crossref indexed 2026/07/30
BACKGROUND: The performance of high-frequency oscillatory ventilators (HFOV) differs by the waveform generation mode and circuit characteristics. Few studies have described the performance of piston-type HFOV. The present study aimed to compare the amplitude required to reach the target high-frequency tidal volume ( V T ); determine the relationship between the settings and actual pressure in amplitude or mean airway pressure ( P ¯ aw ); and describe the interaction among compliance, frequency, and endotracheal tube (ETT) inner diameter in 4 HFOV models, including Humming X, Vue (a piston type ventilator commonly used in Japan), VN500 (a diaphragm type), and SLE5000 (a reverse jet type). METHODS: The oscillatory ventilators were evaluated by using a 50-mL test lung with 0.5 and 1.0 mL/cm H 2 O compliance, P ¯ aw of 10 cm H 2 O, frequency of 12 and 15 Hz, and ETT inner diameters 2.0, 2.5, and 3.5 mm. At each permutation of compliance, frequency, and ETT, the target high-frequency V T was increased from 0.5 to 3.0 mL. The change in P ¯ aw from the ventilator (ventilator P ¯ aw ) to Y-piece (Y P ¯ aw ) and alveolar pressure (alveolar P ¯ aw ) and the change in amplitude from the ventilator (ventilator amplitude) to Y-piece (Y amplitude) and alveolar pressure (alveolar amplitude) were determined at high-frequency V T of 1.0 and 3.0 mL. RESULTS: To achieve the target high-frequency V T , the Humming X and Vue required a higher amplitude than did the SLE5000, but the maximum amplitude in the VN500 was unable to attain a larger high-frequency V T . Ventilator P ¯ aw and alveolar pressure decreased at the Y-piece with the Humming X and Vue but increased with the SLE5000. The ventilator P ¯ aw in the VN500 decreased remarkably at a frequency of 15 Hz. The ventilator amplitude in all 4 ventilators decreased while temporarily increasing at the Y-piece in the VN500. CONCLUSIONS: The actual measured value, such as alveolar P ¯ aw and high-frequency V T , varied according to the type of HFOV system and the inner diameter of the ETT, even with identical settings. Clinicians should therefore determine the setting appropriate to each HFOV model.