急性超容血液稀释对血流动力学的影响

目的 观察不同人工胶体液行急性超容血液稀释(AHHD)对血流动力学的影响.方法 45例ASA Ⅰ～Ⅱ级腹部手术患者,随机分为3组:对照组(C组)、6%羟乙基淀粉组(H组)及4%琥珀酰明胶组(G组).在麻醉诱导后开始输液或扩容:C组输入林格液15 ml/kg,H、G组输入林格液15 ml/kg和胶体液20 ml/kg,均在40 min内完成.监测3组术前、麻醉诱导后、输液或扩容20 min、输液或扩容40 min时心率(HR)、平均动脉压(MAP)、中心静脉压(CVP)、心脏指数(CI),外周血管阻力(SVR)的变化.监测H、G组患者扩容前后血细胞比容(Hct)的变化.结果 H、G组在扩容末,Hct下降,H组由术前0.385±0.043降至0.304±0.045,G组由术前0.395±0.035降至0.312±0.038.H、G组HR、MAP、CI、CVP、SVR术前值和麻醉诱导后值与C组的差异没有统计学意义(P>0.05).输液或扩容20 min、输液或扩容40 min时H、G组HR、CI、CVP、MAP高于C组,其差异有统计学意义(P<0.05);在扩容20 ml/kg后H组CVP增高达(13.13±3.51)cm H2O(1 cm H2O=0.098 kPa),G组增加达(14.88±1.33)cm H2O.结论 在40 min内静脉输入20 ml/kg的6%羟乙基淀粉、4%琥珀酰明胶,是一种有效的超容血液稀释方法.但会造成心脏负荷的显著增加,使用异氟醚和硝酸甘油能有效地减轻心脏前负倚.

Effect of acute hypervolemic hemodilution on hemodynamics

Objective To investigate the effect of acute hypervolemic hemodilution on hemodynamics. Methods Forty-five patients undergone abdominal surgery were enrolled in this study and were randomly allocated into three groups:group H performed with acute hypervolemic hemodilution by 6% HES(hetastareh), group G performed with acute hypervolemic hemodilution by 4% gelofusion (succinyl gelatin) and group C (the control group). After 5 min stabilization period of anesthesia, the baseline hcmodynamic data were collected. Hypervolemic hemodilution procedure was then undertaken in group H or G. Fifteen ml/kg of Ringer's solution(lactated R-L)and 20 ml/kg of colloid were infused in 40 min in all the patients. 6% HES was used in group H, while 4% gelofusion in group G. In group C ,only 15 mL/kg of R-L solution was infused. Heart rate (HR), mean arterial pressure(MAP), central venous pressure (CVP), cardiac index (CI), systemic vascular resistance (SVR) were monitored throughout operation. Hematocrit (Hct) was measured before hemodilution and at each stage of hemodilution. Results At the end of hemodilution, Hct was decreased from 0.385±0.043 to 0.304±0.045 in group H, and in group G, was reduced from 0.395±0.035 to 0.312±0.038. In group H and G, the values of HR, MAP, CI, CVP, SVR were not significantly different (P>0.05) before and after induction of anesthesia compared with those in group C. At time point of 20 minutes after transfusion/expansion and 40 minutes after transfusion/expansion, HR, CI, CVP, MAP in group H, G were higher than those in group C, the differences were statistically significant (P<0.05). In group H after 20 ml/kg expansion, CVP increased to (13.13±3.51) cm H2O (1 cm H2O = 0.098 kPa), and in Group G, CVP increased to (14.88±1.33) cm H2O. Conclusion Preoperative acute hypervolemic hemodilution with 20 ml/kg colloid (6% HES or 4% gelofusion) is well tolerated and safe in 40 min for patients without evidence of heart, lung, liver and kidney disease. Although CVP increases significantly during the period of hypervolemic hemodilution, vasodilatation effect of isoflurane and nitroglycerin can well attenuate the preload of the heart.