[Application of acute extreme hypervolemic hemodilution in spine surgery]

To evaluate the security and validity of the acute extreme hypervolemic hemodilution (AEHH) in spine surgery.

Thirteen patients (8 males, 5 females; age, 16-65 years; weight, 50-75 kg) who had undergone major spine operations were enrolled in this study. Eleven of them had undergone anterior decompression, who were given the grafting and the internal fixation for their thoraco-lumber spinal burst fractures; the other 2 patients were given the correction operation for their scoliosis. The baselines of the haematocrit (Hct) were 0.363-0.481 before operation. The patients had no cardiac, pulmonary, hepatic or renal dysfunction or coagulation abnormality. The hemodynamic status and the haematocrit were observed during operation. The parameters of thromboelastography (TEG), arterial blood gas, and electrolytes were measured and observed at the following time points: before AEHH, after AEHH, 60 minutes after AEHH, 120 minutes after AEHH, and the end of the operation. The total fluid volume was recorded.

The autologous blood volume was 1 050-1 575 ml (average, 1 419 +/- 198 ml), plasma substitute 2 100-3 150 ml (average, 2 838 +/- 397 ml), blood loss 1 000-3 130 ml (average, 1 747 +/- 743 ml), urine 450-1 270 ml (average, 871 +/- 374 ml), and the net blood transfusion 1 206-2 661 ml (1 863 +/- 598 ml). The homogenous blood of 400 ml was transfused in 1 patient for making up the blood loss of 3 130 ml. There were no statistically significant differences in the hemodynamic measurements, arterial blood gas, and electrolyte variables when compared with the baseline values before the hemodilution (P > 0.05). The reaction time of TEG was longer 60 minutes after AEHH than before AEHH (P < 0.05); the other parameters of TEG had no differences when compared with the baseline values (P > 0.05).

The AEHH is safe and efficient in reduction of the perioperative homogenous blood transfusion in spine surgery.