Booker P D, Prosser D P, Franks R
Royal Liverpool Children's NHS Trust.
Br J Anaesth. 1996 Nov;77(5):591-6. doi: 10.1093/bja/77.5.591.
We have examined the effect of profound hypothermia on gut mucosal perfusion in 20 infants, aged 1.4-45 weeks, requiring cardiopulmonary bypass (CPB). After induction of anaesthesia, a laser Doppler probe was inserted 8 cm into the patient's rectum to allow monitoring of rectal mucosal perfusion ("flux") throughout operation. Steady-state observation periods (5 min with no change in temperature or mean arterial pressure (MAP) were achieved after 10 min on CPB at 35 degrees C, after CPB-induced cooling to 15-25 degrees C, immediately before rewarming and after rewarming to 35 degrees C. Throughout these periods flow rate was 100 ml kg-1 min-1, packed cell volume was kept constant and Paco2 maintained at 5.3 +/- 0.5 kPa. No vasoactive drugs were used. Initial warm and rewarm MAP values (46 mm Hg) were significantly lower (P = 0.008) than during the cold CPB periods (63 and 64 mm Hg). Mean flux in the first cold period (152) was significantly lower (P = 0.001) than that in the first warm CPB period (211). Post-rewarm flux (127) was significantly lower than all other CPB flux values (P = 0.004). We conclude that although hypothermia significantly reduced mucosal blood flow, rewarming produced even greater reductions in mucosal perfusion that may prove crucial in the development of mucosal hypoxia.
我们研究了深度低温对20名年龄在1.4 - 45周、需要体外循环（CPB）的婴儿肠道黏膜灌注的影响。麻醉诱导后，将激光多普勒探头插入患者直肠8厘米深处，以便在整个手术过程中监测直肠黏膜灌注（“通量”）。在体外循环35摄氏度10分钟后、体外循环诱导降温至15 - 25摄氏度后、复温前以及复温至35摄氏度后，均实现了稳定状态观察期（温度和平均动脉压（MAP）5分钟无变化）。在这些时间段内，流速为100毫升/千克/分钟，血细胞比容保持恒定，动脉血二氧化碳分压维持在5.3±0.5千帕。未使用血管活性药物。初始体温正常和复温时的平均动脉压值（46毫米汞柱）显著低于低温体外循环期间（63和64毫米汞柱）（P = 0.008）。第一个低温期的平均通量（152）显著低于第一个体温正常的体外循环期（211）（P = 0.001）。复温后的通量（127）显著低于所有其他体外循环通量值（P = 0.004）。我们得出结论，尽管低温显著降低了黏膜血流，但复温导致黏膜灌注的降低幅度更大，这可能对黏膜缺氧的发展至关重要。
