흉추 경막외마취가 급성으로 관상동맥 협착을 유발한 개의 심혈관계에 미치는 영향 = The Effects of the Thoracic Epidural Anesthesia on the Cardiovascular System during acute Coronary Artery Stenosis in Dogs

다국어 초록 (Multilingual Abstract)

Thoracic epiduarl anesthesia (TEA) is used during and after thoracic and abdominal surgery and has been reported to abolish pain effectively and to have a beneficial effects on hemodynamic valuables.
This study was done to investigate the cardiovascular effects of thoracic epidural anesthesia during coroary artery stenosis.
In 13 anesthetized dogs, coronary artery stenosis was made by hydraulic vacular occluder and estimated blood flow just distal to stenosis with blood flow meter. After 60 minutes of stenosis of left circumflex coronary artery 0.5% bupivacaine was administered into the thoracic epidural space via a surgically introduced catheter. Recordings and samplings for hemodynamic parameters and free fatty acid were obtained 5, 15, 30, 45, 60 min after left circumflex coronary artery stenosis and epidural blockade.
The results were as follows;
1) Heart rate and blood pressure were significantly reduced 5 and 15 minutes after epidural blockade, respectively (p<0.05).
2) Fifteen minutes after thoracic epidural anesthesia, cardiac output was reduced significantly (p<0.05).
3) There were no significant changes in stroke volume, systemic vascular resistance, pulmonary vascular resistance and central venous pressure.
4) A significant increase in pulmonary capillary wedge presure and pulmonary artery pressure were seen 15 minutes after epidural blockade (p<0.05).
5) The product of heart rate and systolic arterial blood pressure(rate- pressure product, RPP) was markedly reduced after TEA (p<0.05), but no changes in triple index (TI)
6) Concentration of plasma FFA markedly increased after stenosis of the left circumflex coronary artery but re-decreased after epidural blockade(p<0.05).
In summary, thoracic epidural anesthesia may have beneficial effects on hemodynamics by reducing myocardial oxygen demand.