• 作者： 張傳林; 葉富欽; 何維?; 陳幸一
• 作者服務機構： 三軍總醫院外科部麻醉科; 亞東紀念醫院麻醉科; 國防醫學院生理及生物物理學系
• 中文摘要： Sodium nitroprusside（SNP）為常用於「低血壓麻醉」之一種血管擴張劑，本研究之目的在觀察利用sNP做低血壓麻醉而使周邊器官血流降低時，腦血流是否嚴重減少。利用15隻pentobarbital麻醉之狗，其中7隻以靜脈出流方法測量腦血流，另外8隻則測量後肢動脈血流。調整由靜脈灌注SNP之速率以降低全身血壓（每節約降低5 mmHg），在全身低血壓時，即使血壓已降低至40 mmHg，腦血流仍然相當恆定，而計算出之腦血管阻力則隨著血壓之降低而減少。後肢血流則呈相反的反應，血流隨血壓而降低，當全身血壓降至50 mmHg時，後肢血流僅為未給藥前水平之46.3±7.6％，計算而得之後肢血管阻力在SNP引發之低血壓時呈現增加，最高到達未給藥前水平之126.3±11.2％。結果顯示腦部及後肢在SNP產生之低血壓情況下，血流及阻力之反應兩器官截然不同，如果為了某一周邊器官的手術，需要施行低血壓麻醉，在SNP之灌注下腦血流維持恆定，表示腦部的灌流不致降低至危險之程度。
• 英文摘要： Sodium nitroprusside (SNP) has been commonly used as a vasodilator agent for deliberate hypoten-sion with general anesthesia. The purpose of this study was to observe whether cerebral blood flow (CBF)was significantly reduced when SNP infusion was accomplished to decrease peripheral blood flows withsystemic hypotension. We conducted the experiments in 15 pentobarbital-anesthetized dogs. CBF wasmeasured in 7 dogs using a venous outflow method. Hindlimb blood flow (HBF) serving as a representativeof the peripheral circulations was obtained by flow measurement in the femoral artery in 8 dogs. The sys-temic arteral pressure (SAP) was decreased stepwise (approximately 5 mmHg for each step) by adjustingthe SNP infusion rate. During the systemic hypotension, the CBF remained fairly constant despite a mark-ed decline in the mean SAP to 40 mmHg. The calculated cerebral vascular resistance was progressivelydecreased with the systemic hypotension. On the contrary, a reduction in the HBF was observed accom-panying the fall in SAP. When the mean SAP was decreased to 50 mmHg, the HBF was only 46.3±7.6% ofthe control value. The calculated hindlimb vascular resistance was slightly elevated during the whole courseof SNP-induced hypotension. The results reveal the disparity between the brain and hindlimb in the resis-tance and flow responses to SNP-induced hypotension. The constancy of CBF subserves adequate brainperfusion when deliberate hypotension is conducted for surgery in the peripheral organs.
• 中文關鍵字： deliberate hypotension; anesthesia; nitroprusside; cerebral blood flow; hindlimb blood flow
• 英文關鍵字： --