Abstract

Closed-chest cardiac massage(CCCM) has been thought to prccuce blood flow by compression of the heart between sternum and spine, but contradictory views have been expressed by several investigators, We studied the arterio-venous pressure differences in 15 rabbits to clarify the effect of tourniquets applied on four extremities to mimic the effect of cross clamping of abdominal abdominal aorta in experimenta1 cardiac resuscitation. The experimental animals were divided. into two groups, tourniquet applied group and (●ccntrol) group. This was done to observe the changes of peripheral vascular tone during CCCM with tourniquets applied on four extremities as compared to the control group, The arterio-venous pressure difference generated by CCCM was recorded throughout the experiment with tracing speed of 0. 25cm/sec. The recorded area of arterio-verous pressure difference was measured using planimeter at regular time intervals. The measured areas of both groups were expressed by 10mmHg×4 seconds as 1cm2 for the basic unit. The rapid tracing of the recorded pressure waves was analyzed in both groups. The results obtained were as follows; 1. The area, 1 minute after CCCM was 17. 16±7. 37cm2 in tourniquet group and 8.69±3. 0lcm2 in ccntrol group. This value of tourniquet group was significantly increased as much as 97. 47%(p<0.05). 2. Arterio-venous pressure differences were gradually decreased as time passed by in both groups. Through this experiment, it is inferred that; 1. The application of tourniquets during CCCM helps the central venous pressure to decrease and the arterial pressure increase, thus improving the tissue perfusion. 2. The decrease of jugular venous pressure by tourniquet application may be caused by compIete closure of aortic valve during diastolic phase of CCCM. 3. The decrease of arteria#1 pressure generated by CCCM as time passes by may be due to decreasing the peripheral vascular tone.