Comparing effects of low and high-flow anesthesia on hemorheology and coagulation factors.

OBJECTIVES: In the current study, we compared the effects of low- and high-flow anesthesia techniques on hemorheology and coagulation parameters in patients who received sevofluran.

METHODS: Forty patients classified as Risk Group I-II according to American Society of Anesthesiologists' (ASA) guidelines who were scheduled to undergo general anesthesia were randomly assigned to one of two groups. Low-flow anesthesia was administered to the first group, and high-flow anesthesia was used in the second group. Blood samples were obtained in the preoperative and peroperative periods (at 60 and 120 min) for determination of blood and plasma viscosity, plasma oncotic pressure, international normalized ratio (INR), phorotrombin time (PT), activated partial phorotrombin time (aPTT) and fibrinogen. Blood was also drawn for analysis of factor VIII (FVIII) activity, which was measured in the preoperative period and at postoperative six hour.

RESULTS: The peroperative plasma viscosity was significantly low in Group 1 relative to Group 2. aPTT was significantly elevated at 60 minutes in Group 1 relative to Group 2, but the increase at 120 minutes was not significant.

CONCLUSION: The effects of low-flow anesthesia on hemorheology were greater than those of high-flow anesthesia.