Determination of the standard value of circulating blood volume during anesthesia using pulse dye-densitometry: a multicenter study in Japan

Purpose The standard value for circulating blood volume (BV) during anesthesia was determined by a multicenter study in Japan. The significance of BV on the reduction of blood pressure after the induction of anesthesia was also examined. Methods The study included 184 patients from eight university hospitals. After the induction of anesthesia, pulse dye-densitometry was performed according to a uniform protocol. Factors contributing to reduced blood pressure after induction of anesthesia were examined by multiple logistic regression analysis. Results The mean and standard deviation of BV was 80.0 ± 13.9 ml·kg −1 ; for females and 84.2 ± 15.3 ml·kg −1 for males ( P > 0.05). There was no age difference in terms of BV. After adjusting for the effects of height, weight, and age, the factors predisposing to a reduction in blood pressure of >20 mmHg after induction of anesthesia were found to be age ( P < 0.01) and BV (ml·kg −1 ) ( P < 0.001). Conclusion We determined the BV of anesthetized patients before surgery in Japan using pulse dye-densitometry. It is suggested that age is not a factor regarding BV, and that blood pressure tends to be reduced in hypovolemic patients after induction of anesthesia.