Relationship Between Resonance and Gas Exchange During High Frequency Jet Ventilation

Abstract

We have studied the relationship between gas exchange and mechanical frequency response during high frequency jet ventilation (HFJV) at 0.5-5.0 Hz in anaesthetized pigs. The mechanical gain curve showed a minimal "anti-resonant" response at 0.8 Hz (f1) and a maximal "resonant" response at 5.0 Hz (f2). This finding may be explained by modelling the thorax and abdomen as a system of coupled masses and compliances which undergo two different modes of forced oscillation in the frequency range studied. Gas exchange was optimal in the frequency range between the minimal and maximal responses. The tidal volumes produced were greater than anatomical deadspace, suggesting that gas transport was mainly convective in this range.

High-frequency jet ventilation in European and North American institutions: developments and clinical practice

“…With the double jet technique, we recommend the use of pulse frequencies of about 8±10 Hz and 10±18 bpm for the high-frequency and the low-frequency jet, respectively. The parameters guiding the optimal HF jet rate setting in patients with pulmonary insuf®ciency still have to be investigated and may depend on the resonance of the lung [10,98]. For single-frequency HFJV, jet rates between 120 and 420 bpm (2±7 Hz) and I : E time ratios of 0.3±1.0 are commonly used.…”

High-frequency jet ventilation in European and North American institutions: developments and clinical practice

“…With the double jet technique, we recommend the use of pulse frequencies of about 8–10 Hz and 10–18 bpm for the high‐frequency and the low‐frequency jet, respectively. The parameters guiding the optimal HF jet rate setting in patients with pulmonary insufficiency still have to be investigated and may depend on the resonance of the lung [10,98]. For single‐frequency HFJV, jet rates between 120 and 420 bpm (2–7 Hz) and I : E time ratios of 0.3–1.0 are commonly used.…”

Adult respiratory distress syndrome. Advances in diagnosis and ventilatory management.

“…Although previous studies have not established any advantage of this technique over conventional techniques7 a new philosophy has emerged based on aggressive recruitment and maintenance of lung volume and an attempt to harness proposed enhanced alveolar gas kinetics at the resonant frequency of the lung, thought to be roughly 5 Hz. 8 The APT 1010 machine is a computer controlled ultra high frequency pulse generator capable of frequencies up to 20 Hz. The jet nozzle, situated at the proximal end of the endotracheal tube, entrains humidified oxygen enriched air from a bias gas source.…”

“…She was hypertensive, with a cardiac output of 11 8 1/min and a pulmonary artery occlusion pressure of 14 mm Hg. A full bacteriological screen gave negative results, and she was treated with piperacillin and gentamicin.…”