Pauca A L, Wallenhaupt S L, Kon N D, Tucker W Y
Department of Anesthesia, Bowman Gray School of Medicine, Winston-Salem, NC 27157-1009.
Chest. 1994 Nov;106(5):1358-63. doi: 10.1378/chest.106.5.1358.
To assess the effect of cardiopulmonary bypass (CPB) on muscle blood flow (MBF) when measured in the forearm by venous occlusion plethysmography.
This was a prospective study.
Operating room area of a tertiary care university medical center.
Twenty-seven patients (25 men and 2 women), aged 62 +/- 1.5 years, undergoing elective coronary bypass grafting.
Measurements were made during the surgical procedure: before, during cold and warm, and after discontinuation of CPB.
Changes in forearm blood flow (FBF), derived forearm vascular resistance (FVR), mean arterial pressure (MAP), and cardiac output (CO) were evaluated by repeated measures analysis of variance. The control FBF (measured before CPB) was found to be approximately 50 percent lower than that previously reported for awake volunteers and patients. The FVR was similarly higher. From these low values, the FBF increased significantly (p < 0.001) during normothermic bypass and after CPB. Forearm vascular resistance decreased significantly (p < 0.001) throughout the cold, warm, and postbypass periods. Only during the warm and the postbypass periods did FBF and FVR reach normal values. Mean arterial pressure decreased significantly (p < 0.01) throughout. There was no statistically significant association between any of the variables and FBF or FVR. After correcting for patient and surgical phase variability, only MAP had a statistically significant effect (p = 0.042) on FVR; blood temperature, skin temperature, hematocrit level, PaCO2, serum potassium, and systemic vascular resistance (SVR) had no effect on either FBF or FVR when tested singly or in combination. When correction for multiple comparisons was applied, the lowest probability value became greater than 0.25. There was no correlation between combinations of covariates and FBF or FVR after adjustments for the surgical phase of the study either.
These findings indicate that the increase in MBF seen during warm and the post-CPB periods is only a recovery toward normal blood flow. The role of this change in the low SVR that usually accompanies CPB is equivocal.
通过静脉阻断体积描记法测量前臂肌肉血流量（MBF），评估体外循环（CPB）对其的影响。
这是一项前瞻性研究。
一所三级护理大学医学中心的手术室区域。
27例患者（25名男性和2名女性），年龄62±1.5岁，接受择期冠状动脉搭桥术。
在手术过程中进行测量：CPB前、冷循环和温循环期间以及CPB停止后。
通过重复测量方差分析评估前臂血流量（FBF）、推算的前臂血管阻力（FVR）、平均动脉压（MAP）和心输出量（CO）的变化。发现对照FBF（CPB前测量）比先前报道的清醒志愿者和患者低约50%。FVR同样更高。从这些低值开始，在常温体外循环期间和CPB后，FBF显著增加（p<0.001）。在整个冷循环、温循环和体外循环后阶段，前臂血管阻力显著降低（p<0.001）。仅在温循环和体外循环后阶段，FBF和FVR才达到正常值。平均动脉压在整个过程中显著降低（p<0.01）。任何变量与FBF或FVR之间均无统计学显著关联。在校正患者和手术阶段变异性后，仅MAP对FVR有统计学显著影响（p = 0.042）；单独或联合测试时，体温、皮肤温度、血细胞比容水平、PaCO2、血清钾和全身血管阻力（SVR）对FBF或FVR均无影响。应用多重比较校正后，最低概率值大于0.25。在对研究的手术阶段进行调整后，协变量组合与FBF或FVR之间也无相关性。
这些发现表明，在温循环和CPB后阶段观察到的MBF增加仅是向正常血流的恢复。这种变化在通常伴随CPB的低SVR中的作用尚不明确。
