Application Of Acute Normovolemic Hemodilution With Hypertonic Sodium Chloride Hydroxyethyl Starch In Spinal Surgery

Objective:To investigate the effects of acute normovolemic hemodilution with hypertonic sodium chloride hydroxyethyl starch 40 and hydroxyethyl starch 130/0.4 on hemodynamics,arterial blood gas and thrombosis in patients undergoing lumbar fusion.Methods:Fifty ASA I-II patients,aged 45-65,with hemoglobin>110 g/L,scheduled for elective lumbar fusion surgery,were randomly divided into two groups according to the random number method,with 25 cases in each group.Group H was treated with hypertonic sodium chloride hydroxyethyl starch and group C was treated with hydroxyethyl starch 130/0.4.acute normovolaemic hemodilution（ANH）was performed after induction of anesthesia,and fluid was reinfused at the same time of autologous blood collection,group H:hypertonic sodium chloride hydroxyethyl starch 40 injection（HSH40）4ml/kg was infused back,group C:The same volume of hydroxyethyl starch 130/0.4 sodium chloride injection（HES130/0.4）as autologous blood was transfused.Blood loss was controlled to a hematocrit of 30%after hemodilution in both groups according to the Gross formula.Mean arterial pressure（MAP）and heart rate（HR）were recorded at 5min before blood collection（T₁）,10min after blood collection（T₂）,5min before autologous blood transfusion（T₃）and 10min after blood transfusion（T₄）.Arterial blood gas analysis was performed at T₁,T₂and T₄,and the concentrations of PH,HCT,Hb,Na+,K+,lactic acid and blood glucose were measured.Thrombelastography was performed at T₁and T₄to determine the values of R,K,αand MA.The operation time,blood loss,allogeneic blood transfusion volume,infusion volume,urine volume,and complications during hospitalization were monitored.The main outcome measures were the use of vasoactive agents and the coagulation reaction time during acute normovolemic hemodilution.The secondary outcome measures were perioperative sodium ion concentration,lactic acid concentration,allogeneic blood transfusion volume,fluid infusion volume,arterial blood gas analysis and complications during hospitalization.Results:1.General data:There were no significant differences in age,height,weight,preoperative hemoglobin concentration,Caprini score of deep vein thrombosis（DVT）,and number of surgical segments between the two groups（P>0.05）.2.Hemodynamics:9（36.0%）patients in group H used vasoactive drugs,and 2（8.0%）patients in group C used vasoactive drugs,and the difference was statistically significant（P<0.05）,suggesting that the risk of using vasoactive drugs in group H was higher.There was a significant difference in MAP between group H and group C at T₃（P<0.001）.There was no significant difference in MAP between the two groups at other time points（P>0.05）.Comparison of different time points within the group:in group H,there was significant difference in MAP between T₂,T₃and T₁（P<0.05）,but there was no significant difference in MAP between T₄and T₁（P>0.05）.For group C,there was no significant difference in MAP between T₁and each time point（P>0.05）.3.Thromboelastography:there was no significant difference in coagulation reaction time,blood clot formation time,coagulation Angle and maximum amplitude of thromboelastography between the two groups（P>0.05）.4.Arterial blood gas analysis:Compared with group C,Na⁺concentration in group H increased at T₂and T₄,and the difference was statistically significant（P<0.05）,while there was no statistically significant difference in the concentration of hemoglobin,lactic acid,K⁺,Ca²⁺and blood sugar in the analysis of arterial blood gas between the two groups（P>0.05）.4.There was statistically significant difference in urine volume between group H and group C（P<0.001）,and the urine volume of group H was significantly higher than that of group C.There were no significant differences in operation time,blood loss,autologous blood collection,crystalloid infusion,incision drainage and total hospital stay between the two groups（P>0.05）5.Arterial blood gas analysis:the concentration of Na⁺in group H increased at T₂and T₄,and the difference was statistically significant compared with group C（P<0.05）.There was no significant difference in hemoglobin,lactic acid concentration,K⁺,Ca²⁺and blood glucose concentration in arterial blood gas analysis between the two groups at each time point（P>0.05）.Conclusion:1.It is safe and feasible to use hypertonic sodium chloride hydroxyethyl starch40 and hydroxyethyl starch 130/0.4 for mild acute normovolemic hemodilution in patients undergoing lumbar fusion without increasing the incidence of complications and the possibility of tissue hypoxia.2.The volume expansion effect of hypertonic sodium chloride hydroxyethyl starch in acute normovolemic hemodilution is not lower than that of hydroxyethyl starch 130/0.4.,but increase the incidence of hypotension in the later stage of surgery.During ANH,monitoring and management of volume should be strengthened according to the physical and chemical properties of different fluids.