[Techniques of autologous transfusion in hip surgery: a retrospective study]

A retrospective study was carried out on 99 patients undergoing hip surgery to evaluate the efficacy of three autotransfusion techniques on sparing of homologous blood. Preoperative normovolemic hemodilution (HDN), delayed autotransfusion (ATD) and recuperation of blood lost during surgery (RSPO) were studied. Patients were divided into 5 groups: group HDN, group ATD, group ATD + HDN, group RSPO, and the control group. The hematocrit was followed intra and postoperatively within these five groups, and mean values homologous blood transfusions calculated for each group. Comparison of mean values was performed using variance analysis (p less than 0.02). The association of delayed autotransfusion and preoperative hemodilution was most effective in sparing homologous blood (0.11 +/- 0.3 unit, p less than 0.02): however these results were obtained with a substantial drop in hematocrit which fell well below the 30% minimal accepted value at the end of the operation. There was no significant difference between delayed autotransfusion (0.35 +/- 0.8 unit) and preoperative hemodilution (0.7 +/- .01 unit) in sparing homologous blood. Hematocrit values with delayed autotransfusion were greater than these obtained with preoperative hemodilution. The difference was significant at the beginning of the operation (p less than 0.001), but not significant at the end. Recuperation of blood lost during surgery was least effective in sparing homologous blood (1 +/- 1.2 unit, p less than 0.02). Because of the moderate decrease in hematocrit, there are very few contraindications to delayed autotransfusion. Recuperation of blood lost during surgery should be associated with another autotransfusion technique.(ABSTRACT TRUNCATED AT 250 WORDS)