Normovolaemic haemodilution and intraoperative auto-transfusion in children: experience with 30 cases of spinal fusion.

Based on 30 cases of ventral and/or dorsal spondylodesis in children and adolescents between 3.4 and 19.9 years of age, this report describes a method for the minimization of homologous blood transfusion. This method consists of extreme haemodilution, combined with mild hypothermia and controlled hypotension. After induction of anaesthesia the haematocrit is reduced to 0.20-0.25 by withdrawal of the patient's blood and replacement with Ringer's Lactate in a 3:1 Ringer's blood ratio. The patient's own blood is retransfused if the haematocrit falls below 0.12-0.14 or at the end of surgery. In 12 cases an intraoperative blood recovery system (Cell Saver) was used as an additional autotransfusion technique. During haemodilution no acidosis or rise in serum lactate was found. If the haematocrit fell below 0.20, there was a significant fall of central venous oxygen saturation attributed to increased tissue oxygen extraction. During the first 12-24 postoperative hours all patients showed peripheral oedema and massive diuresis with a tendency to hypovolaemia. In this period close monitoring in the intensive care unit was necessary. Haematocrit and reticulocyte count normalised within 4 weeks. Compared to an earlier series of spondylodesis, wherein all patients received banked blood, homologous blood transfusion was reduced by about 75%. This was due not only to autotransfusion techniques, but also to painstaking surgical haemostasis and restrictive indications for homologous transfusion.