Huang Huimin, Wang Wei, Zhu Demin
Department of Cardiothoracic Surgery, Shanghai Children's Medical Center, Medical College, Shanghai Jiaotong University, Shanghai, China.
ASAIO J. 2007 Nov-Dec;53(6):684-6. doi: 10.1097/MAT.0b013e31815d055d.
Low flow rate perfusion has been recommended in profound hypothermic cardiopulmonary bypass (CPB) in recent years. However, most patients with congenital heart defects are still operated on under moderate hypothermic CPB, where high flow rate perfusion has been adopted by most perfusionists. Fifty patients with congenital heart defects, ranging from 1 to 11 yr of age and 6.5 to 25 kg of weight, were included in the trial. Once on CPB, a high flow rate of 2.37 +/- 0.39 L/min/m was used to cool the patient to 27.3 degrees C +/- 0.84 degrees C rectal temperature, followed by a low flow rate of 1.31 +/- 0.09 L/min/m until the main intracardiac repair was completed and rewarming started. High flow rate was still used in rewarming the patients to a rectal temperature of 35 degrees C-36 degrees C. The total CPB, cross-clamp, and low flow rate perfusion time were 86.4 +/- 26.6, 46.4 +/- 22.3, and 40.7 +/- 22.4 min, respectively. After 24-99 min low flow rate perfusion, venous oxygen saturation remained above 80% for all the patients, and lactate concentration did not increase. Only three patients showed slight metabolic acidosis during CPB and required an extra 6-12 mEq sodium bicarbonate. Average urine output was 199 +/- 155 (50-600) ml during CPB. All patients recovered well after operation. No surgical death or neurologic complications occurred. Low flow rate perfusion might be safely used in moderate hypothermic CPB as long as the oxygen saturation of returned venous blood was kept above 80%.
近年来，在深度低温体外循环（CPB）中推荐采用低流量灌注。然而，大多数先天性心脏病患者仍在中度低温CPB下进行手术，大多数灌注师采用高流量灌注。该试验纳入了50例年龄在1至11岁、体重在6.5至25千克之间的先天性心脏病患者。一旦开始CPB，使用2.37±0.39升/分钟/平方米的高流量将患者体温降至直肠温度27.3℃±0.84℃，随后采用1.31±0.09升/分钟/平方米的低流量，直至心脏内主要修复完成并开始复温。在将患者复温至直肠温度35℃ - 36℃时仍使用高流量。CPB总时间、主动脉阻断时间和低流量灌注时间分别为86.4±26.6分钟、46.4±22.3分钟和40.7±22.4分钟。在低流量灌注24 - 99分钟后，所有患者的静脉血氧饱和度均保持在80%以上，乳酸浓度未升高。只有3例患者在CPB期间出现轻微代谢性酸中毒，需要额外补充6 - 12毫当量的碳酸氢钠。CPB期间平均尿量为199±155（50 - 600）毫升。所有患者术后恢复良好。未发生手术死亡或神经并发症。只要返回静脉血的氧饱和度保持在80%以上，低流量灌注可安全用于中度低温CPB。
