Reduction of 15-hydroxyeicosatetraenoic acid (15-HETE) in tracheal fluid by high frequency oscillatory ventilation.
The effects of high frequency oscillatory ventilation (HFOV) and conventional mechanical ventilation (CMV) on tracheal secretion were compared in 6 anesthetized dogs. Using a double-balloon endotracheal catheter, 5 ml of saline was instilled into an isolated tracheal segment during HFOV and CMV for 10 min respectively. Two eicosanoids, 15-hydroxyeicosatetraenoic acid (15-HETE) and 11-dehydrothromboxane B2 (11-dehydro-TXB2) were measured by radioimmunoassay in each sample. HFOV (stroke volume: 6 ml/kg, f: 10 Hz, bias flow: 5 l/min) and CMV (stroke volume: 12 ml/kg, f: 15/min) were performed in random sequence and achieved comparable gas exchange. The concentration of 15-HETE in tracheal fluid during HFOV (87 +/- 67 pg/ml) was decreased to less than half of that during CMV (286 +/- 184 pg/ml, P less than 0.05), while there was no significant change of 11-dehydro-TXB2 either in tracheal fluid or in plasma. This reduction of 15-HETE was tended to be enhanced by vagotomy (HFOV: 42 +/- 14, CMV: 120 +/- 103 pg/ml) with the concentration ratio of CMV/HFOV remaining unchanged. HFOV may provide hitherto unrecognized advantage over CMV by reducing airway secretion of 15-HETE, a potent inflammatory mediator.
Nagase
T
T
Department of Geriatrics, Faculty of Medicine, University of Tokyo, Japan.
Fukuchi
Y
Y
Shimizu
T
T
Matsuse
T
T
Orimo
H
H
D000818:Animals; D002408:Catheters, Indwelling; D004285:Dogs; D006612:High-Frequency Ventilation; D006893:Hydroxyeicosatetraenoic Acids / Q000097:blood / Q000378:metabolism*; D011863:Radioimmunoassay; D013929:Thromboxane B2 / Q000031:analogs & derivatives* / Q000097:blood / Q000378:metabolism; D014132:Trachea / Q000378:metabolism*; D014628:Vagotomy
D006893:Hydroxyeicosatetraenoic Acids; D013929:Thromboxane B2; C049235:11-dehydro-thromboxane B2; C025984:15-hydroxy-5,8,11,13-eicosatetraenoic acid