Blood volume during transurethral prostatic resection

The variations in blood volume (BV), occurring in the course of 61 transurethral prostatic resections and estimated by the haemoglobin dilution method, were examined in relation to the type and volume of i.v. fluid given, the amount of irrigant absorbed and the blood loss. When dextran 40 was used (n = 16), the BV increased within 10 min by 2.7 times the volume infused, while for cumulative data relating to several 10-min periods in the course of surgery this factor was 1.3; for acetated Ringer solution (n = 45), the respective values were 0.5 and 0.3-0.4. The half-life of absorbed irrigating fluid in the circulation was between 5 and 10 min. In patients receiving dextran 40 the BV decreased by the volume of blood lost; however, when acetated Ringer solution was given, the BV decreased by only 60% of the blood loss.