Blomberg S, Ricksten S E
Department of Anaesthesia and Intensive Care, Sahlgrens Hospital, Sweden.
Acta Anaesthesiol Scand. 1990 Jan;34(1):1-7. doi: 10.1111/j.1399-6576.1990.tb03032.x.
The study aimed to compare the effects of thoracic epidural anaesthesia (TEA) with those of the beta-adrenoceptor blocker, metoprolol, on central haemodynamics in conscious rats with acute myocardial infarction. During methohexital anaesthesia, appropriate vascular catheters were inserted, a thoracic epidural catheter was implanted and the left coronary artery was ligated. A recovery period of 1-2 h elapsed after termination of surgery and anaesthesia. Experiments were performed on four separate groups of animals (A-D). In Group A (n = 10) mean arterial pressure (MAP), heart rate (HR), and cardiac output (CO) were measured, and stroke volume (SV) and systemic vascular resistance (SVR) were calculated before and 10-15 min after the induction of TEA (bupivacaine 5 mg.ml-1). In Group B (n = 6) left ventricular end-diastolic pressure (LVEDP) and maximal dP/dt were recorded as in Group A. In Group C (n = 10) central haemodynamics were measured 10 min after i.v. metoprolol (0.5 mg.kg-1) and again 10-15 min after the addition of TEA. In Group D (n = 6) LVEDP and max dP/dt were measured as in Group C. The reduction in CO, SV, HR and max dP/dt was of the same magnitude with TEA and metoprolol. TEA lowered MAP by 17%, while metoprolol did not change MAP. Metoprolol caused an increase in LVEDP from 20.8 +/- 1.8 to 27.5 +/- 2.7 mmHg (2.8 +/- 0.2 to 3.7 +/- 0.4 kPa) (P less than 0.01), while TEA induced a decrease in LVEDP from 24.2 +/- 1.4 to 17.8 +/- 1.6 mmHg (3.2 +/- 0.2 to 2.4 +/- 0.2 kPa) (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
本研究旨在比较胸段硬膜外麻醉（TEA）与β-肾上腺素能受体阻滞剂美托洛尔对急性心肌梗死清醒大鼠中心血流动力学的影响。在甲己炔巴比妥麻醉期间，插入合适的血管导管，植入胸段硬膜外导管并结扎左冠状动脉。手术和麻醉结束后经过1 - 2小时的恢复期。对四组不同的动物（A - D组）进行实验。A组（n = 10）在诱导TEA（布比卡因5 mg·ml⁻¹）前及诱导后10 - 15分钟测量平均动脉压（MAP）、心率（HR）和心输出量（CO），并计算每搏输出量（SV）和全身血管阻力（SVR）。B组（n = 6）同A组记录左心室舒张末期压力（LVEDP）和最大dP/dt。C组（n = 10）静脉注射美托洛尔（0.5 mg·kg⁻¹）10分钟后以及加用TEA后10 - 15分钟测量中心血流动力学。D组（n = 6）同C组测量LVEDP和最大dP/dt。TEA和美托洛尔使CO、SV、HR和最大dP/dt降低的幅度相同。TEA使MAP降低17%，而美托洛尔未改变MAP。美托洛尔使LVEDP从20.8±1.8升高至27.5±2.7 mmHg（2.8±0.2至3.7±0.4 kPa）（P＜0.01），而TEA使LVEDP从24.2±1.4降低至17.8±1.6 mmHg（3.2±0.2至2.4±0.2 kPa）（P＜0.05）。（摘要截短于250字）
