1987 Volume 16 Issue 2 Pages 847-850
Using a hematocrit continuously measuring system we developed earlier, we monitored changes in the circulating blood volume during HD in order to determine a possible relationship between symptomatic hypotension and blood volume. The blood volume when symptomatic hypotension developed did not always coincide with the lowest level during HD. In some patients, it was 10 percent or more over the lowest level. The minimum level of circulating blood volume was reached approximately I hour after symptomatic hypotension occurred. This suggests that there is variation of compensatory mechanisms during HD in order to maintain blood pressure in relation to decreases in the blood volume. We noted no abrupt decrease in the blood volume prior to the symptomatic hypotension, and it was abvious that the plasma refilling rate did not vary either. This indicates that, in the mechanisms of the symptomatic hypotension, there is no water transfer from the intravascular space to the interstitial space.
