Slater J M, Orszulak T A, Cook D J
Department of Anesthesiology, Mayo Clinic and Foundation, Rochester, Minnesota 55905, USA.
Ann Thorac Surg. 2001 Aug;72(2):542-7. doi: 10.1016/s0003-4975(01)02778-3.
Cardiopulmonary bypass (CPB) may decrease oxygen delivery relative to the nonbypass state. We predicted that a hierarchy of regional blood flow could be characterized under hypothermic (27 degrees C) CPB.
Ten pigs underwent bypass at 27 degrees C. Fluorescent microspheres were administered before and during CPB at four randomized flows: 1.9, 1.6, 1.3, and 1.0 L x min(-1) x m(-2). At completion, tissue samples were obtained from brain, renal cortex and medulla, pancreas, small bowel, and limb muscle for regional blood flow determination.
Cerebral blood flow remained unchanged between CPB flows of 1.9 and 1.3 L x min(-1) x m(-2). Renal perfusion was stable between flows of 1.9 and 1.6 L x min(-1) x m(-2), whereas perfusion of small bowel decreased linearly with pump flow. Pancreatic perfusion was unchanged over the range of flows studied; muscle blood flow was profoundly reduced at the highest CPB flow and further decreased if pump flow was reduced below 1.6 L x min(-1) x m(-2).
This study characterizes the organ-specific hierarchy of blood flow and oxygen distribution during hypothermic CPB. These dynamics are relevant to clinical decisions for perfusion management.
与非体外循环状态相比，体外循环（CPB）可能会减少氧输送。我们预测在低温（27摄氏度）CPB下可确定区域血流的层级关系。
十头猪在27摄氏度下进行体外循环。在CPB之前和期间以四种随机流量（1.9、1.6、1.3和1.0L·min⁻¹·m⁻²）注入荧光微球。结束时，从脑、肾皮质和髓质、胰腺、小肠和肢体肌肉获取组织样本以测定区域血流。
在1.9至1.3L·min⁻¹·m⁻²的CPB流量之间，脑血流保持不变。在1.9至1.6L·min⁻¹·m⁻²的流量之间，肾灌注稳定，而小肠灌注随泵流量呈线性下降。在所研究的流量范围内，胰腺灌注不变；在最高CPB流量时肌肉血流显著减少，若泵流量降至1.6L·min⁻¹·m⁻²以下则进一步减少。
本研究确定了低温CPB期间器官特异性的血流和氧分布层级关系。这些动态变化与灌注管理的临床决策相关。
