Hemodynamics Following Normovolemic Hemodilution in Elderly Patients

Abstract

The hemodynamic effects of acute hemodilution with dextran 70 as dilutional agent were evaluated in a group of elderly patients (mean age 68, range 60-79 years) anesthetized with neurolept analgesia. The isovolemic exchange of 1.1 liter of blood (mean) with a 6% solution of dextran 70 decreased the hematocrit value from 41 to 28%. As cardiac index did not exchange, the oxygen transport capacity was significantly reduced. The main compensating mechanism for this was an increased extraction of oxygen in the tissues and, to a minor extent, a raised arterial oxygen tension. The results of this study suggest that intentional hemodilution should be used with caution in aged patients.

Hemodynamic Response of Elderly Patients Undergoing Major Surgery under Moderate Normovolemic Hemodilution

“…Other studies have shown the same results [2,3,[6][7][8][9], In contrast to these findings, Rosenberg and WulJ'[ \ 1,12] reported no sig nificant modification of cardiac output in patients over 60 years, together with a de crease in oxygen consumption. The explana tion of these results may lie in the fact that in Rosenberg and Wulfs study, hemodilution was undertaken after the patients had been anesthetized and it is well known that anes thesia decreases cardiac output.…”

“…In clinical studies on young patients, the same compensatory mechanism has been re ported [4,7,14], However, as far as its use in patients over 60 is concerned, not all authors agree as to the innocuity of MNH [12].…”

Influence of crystalloid and colloid replacement solutions on hemodynamic variables during acute normovolemic hemodilution

“…10 However, multiple clinical studies of ANH have yielded conflicting results. 8,[11][12][13][14][15][16] The type and amount of replacement fluid used, and the specific anesthetic drugs administered may alter the patient's physiologic response to ANH. Our results demonstrated no change in CI, a stable or decreased HR, stable VO 2 , and increased O 2 Ex, regardless of the fluid used.…”

The combination of hemodilution and controlled hypotension: physiology and clinical application

“…In anesthetized patients during hemodilution, cardiac output may [21,22] or may not [19,20,23] increase, but oxygen extraction is increased [19,20,23]. Spahn et al [21] showed that in clinical studies with anesthetized elderly patients, the hemodiluted anemia was fully compensated by an increased cardiac output and an increased oxygen extraction.…”