Acute Normovolemic Haemodilution In Patients Undergoing Lumbosacral Spine Surgeries

Abstract

Introduction: Extensive surgical procedures, like lumbosacral spine surgeries, involve significant blood loss, and increasing reliance on homologous blood transfusion, which carries risks such as infections, immunosuppression, and transfusion reactions. Acute Normovolemic Haemodilution (ANH), a blood conservation strategy, offers a safer and cost-effective alternative by withdrawing the patient’s blood preoperatively, maintaining normovolemia with crystalloids or colloids, and reinfusing fresh blood intraoperatively.

Methodology: This randomized control study included 60 patients undergoing elective lumbosacral spine surgeries, divided equally into Group HBT (Homologous Blood Transfusion) and Group ANH (Acute Normovolemic Haemodilution). Hemodynamic parameters (heart rate, blood pressure, MAP), haematological indices (haemoglobin, haematocrit), coagulation profiles (platelet count, aPTT, INR), electrolyte levels, and blood loss were monitored pre-, intra-, and post-operatively. Statistical analysis was performed using SPSS v20.0, and a p-value of <0.05 was considered significant.

Results:Hemodynamic parameters: At the end of ANH, Group ANH showed a significant decrease in systolic (8%) and diastolic blood pressure (7%) compared to Group HBT (p<0.05), with MAP also falling significantly (p<0.05) but clinically manageable.

Haematological changes: Haemoglobin decreased by 1.1 g/dL in Group ANH versus 0.8 g/dL in Group HBT (p<0.05), while haematocrit fell 2.9% versus 1.9%, respectively.

Blood loss and EABL: Group ANH had a significantly higher Estimated Allowable Blood Loss (701.8 ± 151 ml) compared to Group HBT (487.1 ± 126 ml) (p<0.001), though actual blood loss was similar (p>0.05).

Coagulation and electrolytes: No significant differences were observed in coagulation profiles (aPTT, INR) or electrolyte levels (p>0.05).

Conclusion: ANH is a safe, feasible, and effective technique for reducing homologous transfusion requirements in spine surgeries. It ensures hemodynamic stability, increases allowable blood loss, and has minimal impact on coagulation and electrolyte balance.