ABSTRACT
Objective To assess the effect of acute hypervolemic hemodilution (AHH) with different hemodiluents on activation of platelets. Method Twenty ASA I-II patients undergoing total hip replacement under general anesthesia were enrolled in this study. They averaged 54 ~ 76 years and 50 ~ 74 kg. The patients were premedicated with intramuscular phenobarbital 2 mg.kg-1 and atropine 0.01 mg. kg-1 . Anesthesia was induced with fentanyl 2ug. kg-1 , dropendol 50 ug. kg-1 , midazolam 40 ug. kg-1 and propofol 1 mg.kg-1. Tracheal intubation was facilitated with vecuronium 0. 1 mg.kg-1 . Anesthesia was maintained with infusion of propofol (2-4mg.kg-1. h-1) and vecuronium (0.06-0.2 mg. kg.h-1) and isoflurane inhalation. Radial artery and right suhelavian vein were eannulated for BP and CVP monitoring. The patients were randomly divided into 2 groups with 10 patients in each group : (A) HES group received hydroxyethyl starch (HES) 25 ml.kg-1 and (B) LR group received Ringer's lactate solution 25 ml.kg-1. In both groups HES or RL solution was infused at a rate of 30 ml-kg-1.h-1 after induetion oi anesthesia. Venous blood samples were taken before induction of anesthesia (T1 ), before AHH (T1 ), 15 min ( T3 ) , 30 min ( T4 ) and 45 min ( T5 ) after the beginning of AHH for determination of the percentage of CD62P and CD63 positive platelet using flow eytometry. ECG, HR, MAP, CVP and urine output were continuously monitored. Small doses of nitroglyeerin were given according to CVP monitoring. Results CD62P expression at T3 , T4 and T5 was significantly higher than that at T, ( P