Effect of acute hypervolemic hemodilution on EC50 of propofol by TCI for loss of consciousness
- VernacularTitle:急性高容量血液稀释对患者靶控输注异丙酚意识消失时EC50的影响
- Author:
Zhisong LI
;
Li LI
;
Quancheng KAN
;
Wei ZHAN
- Publication Type:Journal Article
- Keywords:
Hemodilution;
Propofol;
Dose-response relationship;
drug;
Drug delivery systems
- From:
Chinese Journal of Anesthesiology
2008;28(10):901-904
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the effect of acute hypervolemic hemodilufion (AHHD) on EC50 of propofol by target-controlled infusion (TCI) for loss of consciousness (LOC). Methods Sixty ASA Ⅰ or Ⅱ patients aged 18-64 yr scheduled for vertebral eolunm or total hip replacement surgery were randomly divided into 4 groups (n = 15 each) : group Ⅰ target plasma concentration of propofol (Tp) ;group Ⅱ target effect-site concentration of propofol (Te) ;group Ⅲ AHHD + Tp and group Ⅳ AHHD + Te. All the patients recoived iv infusion of lactated Ringer's solution 0.7 ml·kg-1 ·h-1 via peripheral vein for 30 min. At the same time 4% gelofusion 15 ml/kg was infused over 30 min via internal jugular vein in group Ⅲ and Ⅳ. At the end of gelofusine infusion TCI of propofol was started. The initial target concentration was set at 1.2 μg/ml. After the target concentration was steadily maintained for 30 s, the consciousness of the patients was evaluated by an anesthesiologist not involved in the study using OAA/S scale. The target concentration was increased in 0.3 μg/ml increment until the patients lost consciousness (OAA/S = 0). The target plasma concentration and effect-site concentration were then recorded. EC50 and 95% confidence interval (CI) of propofol for LOC were calculated by probit analysis. Results The ECho (95 % CI) of propofol for patients in group Tp, Te, AHHD + Tp and AHHD + Te (group Ⅰ-Ⅳ) were 3.74 (3.46-4.16), 2.32 (2.17-2.42), 4.12 (3.81-4.32) and 2.38 (2.14-2.56) μg/ml respectively. EC50 was significantly higher for loss of consciousness in AHHD + Tp group (group Ⅲ)than in Tpgroup (group Ⅰ), but there was no significant difference in EC50 between group Te and group AHHD + Te. Conclusion AHHD can increase the EC50 of target plasma concentration of propofol by TCI for LOC but has no effect on EC50 of target effect-site concentration.
