肺「毛細管」圧に関する研究(第1報) : 左心房圧との関係及び急性肺栓塞の影響

Introduction The technique of estimating pulmonary 'capillary' pressure established by Hellems and coworkers, is very important in the study of hemodynamics of pulmonary circulation. But many problems remain to be solved concerning pulmonary 'capillary' pressure (wedge pressure, WP). Now the focus of the dispute concentrates on the next two points : 1. Does WP indicate pulmonary capillary pressure, or some other pressure?2. Has the curve of WP a cyclic variation similar to that of left atrial pressure?It is the purpose of this report to solve these fundamental problems as for WP.Methods and results The pressure was recorded with the Hamilton-styled optic manometer made by ourselves, I take O point for pressures at the midpoint between the anterior and posterior chest wall. The average pressure was calculated of 2 breaths at least.1. Of the same person WP recording at the different branches of pulmonary artery were exactly or almost identical. I made further study on this subject.2. A normal dog was anesthetized by injecting 1cc of 1% morphine hydrochloride per 1kg of the body weight and inserted with the catheter both into the carotid vein and carotid artery. Pulmonary artery pressure and the pulmonary venous wedge pressure, WP and the left atrial pressure was recorded simultaneously.I was found to average 6.1mmHg in normal 9 dogs, and WP and mean left atrial pressure as recorded simultaneously were nearly identical, while mean venous WP and mean pulmonary artery pressure nearly identical.In some cases curve of WP had a cyclic variation similar to that of left atrial pressure, but in others no cyclic variation.In the former there was significant correlation between WP and left atrial pressure. However, in the latter such correlation were lacking. Also in the former it was observed that WP respiratory variation was in parallel to that of the left atrial pressure, while in the latter it was not observed. The zigzag of the WP curve which has no correlation with the left atrial pressure, -seemly caused by shaking of the catheter-did not seem to effect on the difference between WP and the left atrial pressure.Curve of WP lacked the depression corresponded to Y depression of left atrial pressure. Segment X, a wave designation by Maekawa as curve of suction, was somewhat less than the corresponding depression of left atrial pressure curve.3. Pulmonary embolism was produced in normal anesthetized dogs by injecting a one per cent suspension of lycopodium spores in volume of 20-30cc. into the vein of the fore-limb. Immediately after the injection, pulmonary artery pressure and venous WP elevated nearly in a parallel fashion, while WP and left atrial pressure remained unchanged.4. Following injection of lycopodium spores, air embolism was produced artificially with anticipation that air bubbles may occlude the lumen of larger vessels than those occluded by lycopodium. Venous WP falls down in some cases nearly equal to the level of WP after injection of air in contrast with a steeply elevation of pulmonary artery pressure. In other cases venous WP failed to descend so low as WP. WP remained still unchanged.In the test 3, the spore produced the embolism just beforehand the pulmonary capillary and at that part the pressure curve was apparently supposed to turn upwards.In the test 4, it was understood that the air produced the embolism in the larger vessels than those which the spore aid. But the places would vary in each cases. When the catheter comes into the small branches of the pulmonary artery, the blood pressure in the down-flow would be stopped of the pulmonary blood circulation. In this case, WP should show the blood pressure on the spot where the blood flow which is effective to the pressure appears for the first time in the down-flow.