Acute normovolemic hemodilution in children submitted to posterior spinal fusion.

BACKGROUND AND OBJECTIVES Acute Normovolemic Hemodilution (ANH) is a simple and low-cost autologous transfusion method. This study aimed at evaluating whether ANH is able to decrease homologous transfusions in children undergoing posterior spinal fusion and at verifying hemodilution-induced complications in those patients. METHODS Participated in this study 25 children, physical status ASA I and II, submitted to posterior spinal fusion and receiving ANH (group H). Hematocrit values were recorded at surgery beginning and completion, at PACU and hospital discharge. The number of children receiving homologous transfusions during and after surgery, as well as intra and postoperative complications were also recorded. Group H data were compared to other group of children submitted to the same surgical technique, however without ANH (group S). RESULTS Median age and weight for both groups were, respectivelly 13 and 12 years and 41.5 and 34 kg. Immediately after anesthetic induction, 523 ml (mean) of blood were collected from group H, or the equivalent to 17.1% of volemia. Simultaneously, lactated Ringer's solution was started to decrease hematocrit to 28.8% +/- 3.72%. At surgery completion and after autologous blood infusion, hematocrit has reached mean values of 27% in group H and 30.4% in Group S (p = 0.01). At PACU and hospital discharge, differences between hematocrits were not statistically significant. Homologous blood was transfused in 28% of Group H children and 79% of Group S children (p = 0.001). There has been arterial hypotension in 28% of Group H patients and 37.5% of Group S patients (p = 0.9). Four Group S patients had severe postoperative infectious complications. Hospital stay for Groups H and S was, respectively 7.56 +/- 3.203 days for group H, and 9.75 +/- 4.245 days for group S (p = 0.009). Group H has received 3.948 +/- 1.334 ml lactated Ringer's and group S has received 2.234 +/- 953 (p = 0.0001). CONCLUSIONS Normovolemic hemodilution is a safe method to decrease homologous blood needs in children submitted to posterior spinal fusion. There have been no anemia-related complications.