|Budget Amount *help
¥2,700,000 (Direct Cost : ¥2,700,000)
Fiscal Year 1998 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 1997 : ¥2,200,000 (Direct Cost : ¥2,200,000)
With recent ventilators, we can regulate the initial flow rate to modulate inspiratory patters during pressure support ventilation (PSV). Actually, in clinical treatment, it is difficult to measure alveolar pressure (PA) dynamically for the selection of the inspiratory pattern that correct the heteogeneous distribution of PA.We studied which is the most optimal one among four inspiratory patterns during PVS to homogenize he heterogeneous distribution of PA in dogs. In each inspiratory pattern, 10 cm H2O of the selected pressure rising time (PRT) : 0,025,0.5, or 0.75 second. We performed simultaneous PA measurement in each of lobes dynamically with an alveoar capsule method. After the control study in normal lung models, we tried to determine the optimal inspiratory pattern in the models with septic pulmopnary edema made by administration of interleukin-1 and tumor necrosis factor.
In normal lung models, the more slowly the selected pressure support level was reached, the higher was the negative PA in the initial inspiration. End inspiratory PA tended to be highest in the inspiraytory pattern with 0.5 second of he PRT in both nondependent zone (NDZ) and dependent zone (DZ), which had no difference among each PRT.In septic lung models, measurements of PA with the alveolar capsule method were very difficult by increased secretion from alveoil.
We made it clear that the transmissions of pressure to alveoli were improved when the adequate determination of he PRT was done during PSV in normal lung modeless. Adequate PRT may correct the heterogeneous distribution of PA in septic lung models. It will be necessary to improve the methods to measure PA for the additional investigations about septic lung models.