Evaluation of acute isovolemic hemodilution with halothane-induced hypotension in pediatric anesthesia

ABSTRACT

The effects of combined acute isovolemic hemodilution and halothane induced hypotension on some hemodynamic parameters, arterial blood gases, acid-base status and the operative blood loss were studied in 20 children scheduled for major intraabdominal operations. The blood was withdrawn via the central venous line and simultaneously replaced with three times the volume of Ringer's lactate solution. Autologous blood was reinfused either when the hematocrit value dropped to 15% or otherwise at within mean arterial blood pressure range from 54.30 +/- 1.88 to 65.77 +/- 2.08 torr. The minimal mean hemoglobin concentration value was 6.20 +/- 0.09 g/dl with a corresponding mean hematocrit value of 20.1 +/- 1.90%. The mean PaO2 [on 100% O2] dropped significantly during the hemodilution to the minimal mean value of 385.8 +/- 11.55 torr [p <0.05] and postoperatively to the mean value 386.5 +/- 10.99 torr [p <0.05]. PaCO2, standard bicarbonate, base deficit and pH were unchanged. No single case needed homologous transfusion. In conclusion, the combined isovolemic hemodilution and halothane-induced hypotension is a safe and reliable technique for reducing the intraoperative bleeding. It can be employed as one component of blood conservation program