Effect of acute normovolemic hemodilution and nitroglycerin-induced hypertension on homologous blood transfusion requirement and hemodynamics in total hip arthroplasty

Abstract

Blood transfusion requirement and hemodynamic effects of acute normovolemic hemodilution and nitroglycerin-induced hypotension were studied in this report. Thirty patients treated for total hip arthroplasty were randomly assigned in 3 groups of to each. Group I had acute normovolemic hemodilution and Group II had nitroglycerin-induced hypotension. Group III was considered as control group. For patients undergoing acute normovolemic hemodilution, 2 units of blood was collected in standard blood bags and replaced with an equal volume of hydroxyethyl starch [HES (200/0.5 6 %)], immediately after the induction of anaesthesia. In nitroglycerin-induced hypotension group, nitroglycerin was infused at a rate sufficient to reduce systolic and diastolic blood pressures to 80 and 50 mmHg respectively, before initiation of surgery. When the hematocrit (htc) was reduced to 25 %, autologous blood was transfused to group I and homologous blood to the other groups, until the htc reached 30 % postoperatively. The mean homologous transfusion requirement was significantly fewer in acute normovolemic hemodilution group (1.3 ± 0.82 U) than the nitroglycerin-induced hypotension (2.3 ± 0.82 U) and control (2.7 ± 1.16 U) groups. Increase in heart rate was found in the nitroglycerin-induced hypotension. group during all periods. We conclude that acute normovolemic hemodilution may be used in order to reduce the need of homologous blood transfusion in healthy patients and normovolemic hemodilution is more effective than nitroglycerin-induced hypotension for reducing homologous blood transfusion requirement.