Effect of acute hypervolemic hemodilution on the difference between the target and actual measured plasma concentration of propofol during target-controlled infusion / 中华麻醉学杂志

ABSTRACT

1 000 rnl were randomly divided into 2 groups AHHD group ( n = 18) and control group ( n = 18). The patients were premedicated with intramuscular atropine 0.007-0.01 mg?kg-1 . Radial artery and right internal jugular vein were cannulated before induction of anesthesia for MAP and CVP monitoring, blood sampling and fluid administration. Anesthesia was induced with TCI of propofol. The target plasma propofol concentration was set at 3 ?g ? ml -1 . When the patients lost consciousness, fentanyl 2 ?g ? kg-1 was given intravenous and tracheal intubation was facilitated by vecuronium 0.1 mg? kg-1 , 10min after intubation additional fentanyl 2 ?g? kg-1 and vecuronium 0.08 mg? kg-1 were given. In AHHD group lactated Ringer's solution 10 ml ? kg-1 was infused over 30 min before TCI propofol was started. 10 min after start of TCI propofol 6% HES 20 ml? kg-1 was infused within 30 min. In control group the patients received only lactated Ringer's solution 10 ml?kg-1 . TCI of propofol was maintained for 1 h. Arterial blood samples were taken before and 2, 5, 10, 20, 30, 40, 50 and 60 min after TCI propofol was started, and at 2.5, 5, 10, 15, 20, 25, 30 min after termination of TCI propofol for determination of blood concentration of propofol by gas-chromatography - mass spectrometry (GC-MS) . The TCI system comprising Graseby 3 500 infusion pump controlled by Stelpump 1.07 software which included Tackley pharmacokinetic parameters. Results In AHHD group Hb was reduced from initial (130? 14)g?L-1 to (90? 15)g?L-1 and Hct from initial 38% ? 3% to 26% ? 4 % at the end of AHHD. The measured blood propofol concentrations were significantly lower in AHHD group than those in control group at the corresponding time points (P