Effects of acute hypervolemic hemodilution and low central venous pressure on blood loss and liver and renal function in patients undergoing keratectomy

Objective To evaluate the blood-saving effect of low central venous pressure (CVP) combined with acute hypervolemic hemodilution (AHHD) in patients undergoing hepatectomy.Methods Sixty ASA Ⅰ or Ⅱ patients undergoing hepatectomy for primary malignant hepatoma under epidural combined with general anesthesia were randomly divided into 3 groups (n=20 each); Control Group (Group A); LCVP Group (Group B) and LCVP+AHHD Group (Group C).Group A received crystalloid and colloid in a ratio of 1∶1 during the operation to maintain central venous pressure between 6 and 12 cmH2O; in group B,CVP was maintained between 2 and 5 cmH2O,CVP and MAP returned to normal levels by hypervolemic hemodilution with intravenous infusion of crystalloid and colloid after hepatectomy was completed.In Group C,Hematocrit( Hct) was maintained at 25％ ～ 30％ by administration of crystalloid and colloid after tracheal intubation.And CVP and MAP returned to normal levels by hypervolemic hemodilution with intravenous infusion of 6％hydroxyethyl starch 50 ml· kg-1 · h-1 for 10 minutes after hepatic lobectomy was completed.Hemoglobin ( Hb ),Hct,blood coagulation parameters (PT),Alanine aminotransferase (ALT)and renal blood urea nitrogen (BUN),creatinine (Cr)were determined-before operation,immediately after hepatic lobectomy was completed,at the end of operation,1 d and 7days after operation.The amount of infusion,the urine volume,intraoperative blood loss and complications should be recorded.Results Renal function of patients in three groups were within normal range.BUN fluctuations in Group C were more smoothly than in those Group B (P＜0.05),ALT recovery was better (P＜0.05) in Group B and Group C than that in Group A 7 days after operation.Compared with the Group A(1193.00 ± 443.05),the atnount of blood loss in group B (875.00 ± 415.01) and in group C (769.00 ± 405.57) were significantly less (P＜0.05),and urinary output in Group B was significantly less than that in Group C.Compared with the group A(642.00 ± 69.10),the amount of urinary output in Group B (435.50 ± 59.43) and in Group C(491.00 ± 64.70) were significantly less (P＜0.05),and Group C more than in Group B(P＜0.05).Conclusion The LCVP combined with AHHD during hepatic resection can effectively decrease intraoperative blood loss.What's more,the combination of the LCVP and AHHD provides better and safer protection for the functions of liver and kidney than the LCVP alone. Key words: Hemodilution; Central venous pressure; Hepatic lobectomy; Blood loss; Liver function; Renal function