Acute hypervolemic hemodilution effect on oxygen metabolism and blood pharmacokinetics in patients undergoing acute laparotomy during induction of general anesthesia.

Background/aims: To investigate acute hypervolemic hemodilution effect on oxygen metabolism and blood pharmacokinetics in patients undergoing acute laparotomy during Induction of general anesthesia.

Methodology: Forty ASA I-II patients undergoing acute laparotomy were randomly divided into 2 groups (n=20 each): Patients of group A received Voluven 7 ml/kg in 20 mins before induction and 8 ml/kg after induction. Patients of group B received 6 ml/kg/h Plasmalyte A. Hemodynamic parameters MAP, HR and CVP were collected at 6 set points during the surgery: T1: before AHH; T2: before anesthesia induction; T3: right intubation; T4: 10 min after intubation; T5: 20 min after intubation; T6: skin incision. Arterial and venous blood samples were taken for blood gas analysis and determination of lactic acid, Hb and Hct: T1: before AHH, T2: right after AHH, T3: 0.5 h after AHH, T4: l h after AHH. Arterial Oxygen Content (Ca02), Central Venous Oxygen Content (Ccv02) and Oxygen Extraction Ratio (ER02) were calculated.

Results: The hemodynamic parameters were maintained within normal limits during operation in group A (P <0.05). CaO2, CcvO2, ERO2 and Lac between the two groups were no significant difference (P> 0.05). Compared with T1, CaO2/CcvO2 atT 2~4 reduced in both groups (P <0.05). Compared with group A, Hb and Hct in group B increased at T2~4 (P <0.05).

Conclusions: Acute hypervolemic hemodilution in patients undergoing acute laparotomy during Induction of general anesthesia have some preventive hypotension effect, more conducive to the smooth blood pharmacokinetics; Voluven induced expansion of applications is safe and effective, and has no effect on the body's metabolic rate of oxygen.