High-frequency oscillatory ventilation does not decrease endothelin release in lung-lavaged rabbits.
High-frequency oscillatory ventilation (HFO) has been shown to reduce lung injury and pulmonary arterial pressure (PAP). We hypothesized that HFO leads to decreased endothelin 1 (ET-1) and endothelin 3 (ET-3) release when compared to conventional mechanical ventilation (CMV) in lung-lavaged rabbits.


METHODS
Prospective, randomized, controlled animal study. In 26 adult New Zealand White Rabbits ventilated by CMV or HFO under hypoxemic and normoxemic conditions after lung lavage (CMV-hypo: n = 5; CMV-normo: n = 8; HFO-hypo: n = 7; HFO-normo: n = 6) we recorded systemic and PAP, measured blood gases, ET-1 and ET-3 and calculated intrapulmonary venous admixture during a 4-h experiment. ET-1 was significantly increased after lavage (p < 0.05) with no further increase until the end of the experiment. Neither pulmonary arterial nor systemic arterial ET-1 differed between CMV and HFO or between hypoxemia and normoxemia. Systemic arterial ET-3, however, was significantly higher in HFO-hypo than in the other two groups ventilated under normoxemic conditions at the end of the experiment (HFO-hypo vs. CMV-normo, p < 0.05; HFO-hypo vs. HFO-normo, p < 0.05). PAP showed a continuous increase in all groups (p < 0.05). We did not find any correlation between PAP and ET-1 or ET-3. Intrapulmonary venous admixture increased in animals ventilated under hypoxemic conditions, whereas it decreased after lung lavage in those ventilated under normoxemic conditions until the end of the experiment (HFO-normo, p < 0.05).


CONCLUSIONS
This study suggests that HFO does not decrease ET-1 and ET-3 release compared to CMV in lung-lavaged rabbits. Hypoxemia, however, may increase ET-3 release from the lungs, leading to an increased intrapulmonary shunt.
Simma
B
B
Children's Hospital, Department of Biostatistics, University of Innsbruck, Austria. Burkhard.Simma@uibk.ac.at
Gülberg
V
V
Schobel
P
P
Trawöger
R
R
Ulmer
H
H
Gerbes
A L
AL
Putz
G
G
D000818:Animals; D001158:Arteries; D018893:Bronchoalveolar Lavage; D002245:Carbon Dioxide / Q000097:blood; D019332:Endothelin-1 / Q000097:blood; D019334:Endothelin-3 / Q000097:blood; D016232:Endothelins / Q000378:metabolism*; D006612:High-Frequency Ventilation / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D008168:Lung / Q000098:blood supply; D008297:Male; D010100:Oxygen / Q000097:blood; D011651:Pulmonary Artery; D011667:Pulmonary Veins; D011817:Rabbits
D019332:Endothelin-1; D019334:Endothelin-3; D016232:Endothelins; D002245:Carbon Dioxide; D010100:Oxygen