Rooke G A, Freund P R, Jacobson A F
Veterans Affairs Puget Sound Health Care Center, Department of Anesthesiology, University of Washington, Seattle 98108, USA.
Anesth Analg. 1997 Jul;85(1):99-105. doi: 10.1097/00000539-199707000-00018.
Aging and disease may make the elderly patient with cardiac disease particularly susceptible to hypotension during spinal anesthesia. We studied 15 men, 59-80 y old, with histories of prior myocardial infarction (n = 9), congestive heart failure (n = 2), and/or stable myocardial ischemia (n = 11) given spinal anesthesia with 50 mg lidocaine in dextrose. Technetium-99m-labeled red blood cell imaging estimated left ventricular ejection fraction (EF) and changes in blood volume in the abdominal organs and legs. Arterial and pulmonary artery catheters provided hemodynamic measurements. Sensory block averaged T4 (range T1-10). Mean arterial pressure decreased 33% +/- 15% (SD) (P < 0.001), secondary to decreases in vascular resistance (SVR), -26% +/- 13% (P < 0.001) and cardiac output, -10% +/- 16% (P = 0.03). EF increased from 53% +/- 11% to 58% +/- 14% (P < 0.001) while left ventricular end-diastolic volume (LVEDV) decreased (-19% +/- 9%, P < 0.001). Blood volume increased in the legs (6% +/- 6%, P = 0.006), kidneys (10% +/- 9%, P < 0.001), and mesentery (7% +/- 5%, P 0.001) but not in the liver or spleen. Cardiac function was well maintained. We concluded that the primary mechanism of hypotension was a decrease in SVR, not cardiac output, despite the decrease in LVEDV.
衰老和疾病可能使老年心脏病患者在脊髓麻醉期间特别容易发生低血压。我们研究了15名年龄在59至80岁之间的男性，他们有既往心肌梗死病史（n = 9）、充血性心力衰竭病史（n = 2）和/或稳定型心肌缺血病史（n = 11），接受了含50 mg利多卡因葡萄糖溶液的脊髓麻醉。锝-99m标记的红细胞成像估计左心室射血分数（EF）以及腹部器官和腿部血容量的变化。动脉和肺动脉导管提供血流动力学测量。感觉阻滞平均达T4（范围T1 - 10）。平均动脉压下降33%±15%（标准差）（P < 0.001），继发于血管阻力（SVR）下降 - 26%±13%（P < 0.001）和心输出量下降 - 10%±16%（P = 0.03）。EF从53%±11%增加到58%±14%（P < 0.001），而左心室舒张末期容积（LVEDV）下降（-19%±9%，P < 0.001）。腿部血容量增加（6%±6%，P = 0.006），肾脏（10%±9%，P < 0.001）和肠系膜（7%±5%，P < 0.001）血容量增加，但肝脏和脾脏血容量未增加。心脏功能得到良好维持。我们得出结论，尽管LVEDV下降，但低血压的主要机制是SVR降低，而非心输出量降低。
