Comparison of acid-induced inflammatory responses in the rat lung during high frequency oscillatory and conventional mechanical ventilation.
BACKGROUND
The present study was performed to compare the effects of high frequency oscillatory ventilation (HFOV) with conventional mechanical ventilation (CMV) on pulmonary inflammatory responses in a rat acid-induced lung injury model.


METHODS
Anesthetized rats were instilled intratracheally with HCl (0.1 N, 2 mL/kg) and then randomly divided into three mechanical ventilation settings: HFOV (an oscillatory frequency of 15 Hz, mean airway pressure (MAP) of 9 cmH(2)O), CMV at tidal volume of 12 and 6 mL/kg for 5 h.


RESULTS
After HCl instillation, HFOV significantly attenuated the increases in neutrophil infiltration and TNF-α concentration in bronchoalveolar lavage fluid compared with the CMV groups. During HFOV, there was an inhibition of an increase in TNF-α mRNA expression and a decrease in SP-A mRNA expression induced by acid instillation.


CONCLUSIONS
This animal study demonstrates that HFOV is a suitable form of mechanical ventilation to prevent inflammatory responses in acid-induced lung injury.
Jian
Ming-Yuan
MY
The First Department of Internal Medicine, Shinshu University School of Medicine, Asahi, Matsumoto, Japan.
Koizumi
Tomonobu
T
Yokoyama
Toshiki
T
Tsushima
Kenji
K
Kubo
Keishi
K
D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D006612:High-Frequency Ventilation; D006851:Hydrochloric Acid / Q000494:pharmacology; D007249:Inflammation / Q000276:immunology*; D055370:Lung Injury / Q000139:chemically induced / Q000276:immunology* / Q000628:therapy*; D008297:Male; D037662:Pulmonary Surfactant-Associated Protein A / Q000235:genetics / Q000378:metabolism; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012121:Respiration, Artificial; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism
D037662:Pulmonary Surfactant-Associated Protein A; D014409:Tumor Necrosis Factor-alpha; D006851:Hydrochloric Acid