Effects of epidural and spinal anesthesia on blood rheology.

This study was designed to compare the influence of epidural and spinal anesthesia on blood viscosity. We studied 22 patients, ASA classification I, who underwent elective knee or ankle arthroscopy and received epidural (n = 11) or spinal (n = 11) anesthesia with plain bupivacaine, and 10 control volunteers, who did not undergo surgery or receive anesthesia. There were significant decreases in hematocrit, plasma viscosity, and whole-blood viscosity at high (70 s-1), medium (0.5 s-1), and low (0.05 s-1) shear rates. The magnitude of changes was similar in all groups but occurred earlier in the control group (between 10 and 30 min) and after spinal administration (between 10 and 30 min) rather than after epidural administration (between 30 and 60 min) of bupivacaine. Only spinal anesthesia was associated with a decrease in erythrocyte deformability. The observed rheologic changes are attributed to hemodilution from the intravenous administration of fluids and the redistribution of fluid in the intravascular and extravascular compartments after sympathetic blockade and to postural changes rather than the effect of bupivacaine on blood elements.     

胰岛素与胰岛素样生长因子在肝脏副交感神经反射中的作用

目的 :为了检验一个新的学说 :是胰岛素而不是胰岛素样生长因子 (IGF-1 )激活肝脏副交感神经反射。方法 :应用快速胰岛素敏感试验 (RIST)方法。其指标是 :在胰岛素或胰岛素样生长因子 (IGF- )推注后为了维持大白鼠实验期间的正常血糖水平而灌注的葡萄糖量。我们比较了胰岛素 5 0 mu/kg及 IGF- 2 0 0μg/kg输入实验的大白鼠体内后的血糖贮存量。结果 :IGF- 2 0 0 μg/kg与胰岛素 5 0 mu/kg有相似的低血糖作用。通过输入阿托品 (1 .0 mg/kg)阻断肝脏副交感神经反射导致胰岛素抵抗 ,而对 IGF- 无影响。结论 :是胰岛素而不是IGF- 激活肝脏副交感神经反射释放出一种激素刺激血糖在骨骼肌的摄取     

Acetabular fractures: optimal imaging

In 19 cases of acetabular fracture, computed tomography (CT) with volumetric three-dimensional (3D) reconstructions displayed as video loops about horizontal and vertical axes of rotation replaced the traditional imaging combination of CT and multiple plain radiographs, while offering significant advantages. Overlying bowel content or foreign matter obscured detail in 36 of 45 plain radiographic views, and positioning or radiographic technique was suboptimal in 21. Three-dimensional reconstructions completely eliminated these problems. These 3D reconstructions accurately simulated oblique, inlet, and tangential views in all cases. In ten of 19 cases a nonconventional oblique view, and in 13 of 19 cases a cephalocaudal angulation other than the inlet, tangential, or anteroposterior view, best demonstrated the fracture. Elimination of five plain radiographs resulted in a skin radiation dose savings of 5 rad (50 mGy). No difficult or painful patient positioning was required beyond that necessary for the standard CT examination.