Department of Surgery, Division of Cardiac Surgery, London Health Sciences Centre, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada.
Ann Thorac Surg. 2012 Dec;94(6):2046-53. doi: 10.1016/j.athoracsur.2012.05.065. Epub 2012 Jul 25.
Controversy exists regarding the optimal perfusion modality during cardiopulmonary bypass (CPB). Here we compare the effects of pulsatile versus nonpulsatile perfusion on microvascular blood flow during and after CPB.
High-risk cardiac surgical patients were randomly assigned to have pulsatile (n=10) or nonpulsatile (n=10) flow during CPB. The sublingual microcirculation was assessed using orthogonal polarization spectral imaging. Hemodynamic and microvascular variables were obtained after anesthesia (baseline), during CPB, and post-CPB.
Compared with baseline, a normal microcirculatory blood flow pattern was accomplished at all time points under pulsatile flow conditions. Peaking 24 hours postoperatively, a higher proportion of normally perfused microvessels occurred under pulsatile versus nonpulsatile flow (56.0%±3.9% vs 33.3%±4.1%; p<0.05). Concurrently, pulsatility resulted in a reduction in the prevalence of pathologic hyper-dynamically perfused vessels (6.0%±3.4% vs 19.6%±8.8%; p<0.05). Leukocyte adherence decreased relative to the nonpulsatile group both during and after CPB. Furthermore, peak lactate levels were reduced under pulsatile flow conditions postoperatively.
Pulsatile perfusion is superior to nonpulsatile perfusion at preserving the microcirculation, which may reflect attenuation of the systemic inflammatory response during CPB. We suggest the implementation of pulsatile flow can better optimize microvascular perfusion, and may lead to improved patient outcomes in high-risk cardiac surgical procedures requiring prolonged CPB time.
体外循环（CPB）期间的最佳灌注方式存在争议。在此，我们比较了搏动与非搏动灌注对 CPB 期间和之后的微血管血流的影响。
高危心脏手术患者被随机分配在 CPB 期间接受搏动（n=10）或非搏动（n=10）血流。使用正交偏振光谱成像评估舌下微循环。在麻醉后（基线）、CPB 期间和 CPB 后获得血流动力学和微血管变量。
与基线相比，在搏动血流条件下，所有时间点均实现了正常的微循环血流模式。术后 24 小时达到峰值，搏动血流下正常灌注的微血管比例高于非搏动血流（56.0%±3.9% vs 33.3%±4.1%；p<0.05）。同时，搏动导致病理性高动力灌注血管的发生率降低（6.0%±3.4% vs 19.6%±8.8%；p<0.05）。白细胞黏附在 CPB 期间和之后均低于非搏动组。此外，术后搏动血流条件下的乳酸峰水平降低。
搏动灌注在维持微循环方面优于非搏动灌注，这可能反映了 CPB 期间全身炎症反应的减弱。我们建议实施搏动血流可以更好地优化微血管灌注，并可能导致在需要长时间 CPB 的高危心脏手术中改善患者结局。
