Intraoperative Normovolemic Hemodilution Combined with the Reinfusion of Scavanged Blood and Hypotensive Anesthesia Reduces the Need for Blood Transfusions after Spine Fusions

Introduction: At our institution patients undergoing 1-3 level posterior spinal fusions with instrumentation (PSF) donate two units of blood preoperatively, lose 600-1500cc of blood intraoperatively, and often require two units of blood perioperatively. Problems associated with autologous blood donation programs include: 1) donation close to surgery often results in anemic patients the day of surgery; 2) patients can receive the incorrect autologous unit or a contaminated unit; 3) expense of predonation; and 4) if the surgery is postponed the stored units may expire. Acute normovolemic hemodilution in the operating room should reduce the need for presurgical donation for PSF.

Material & Methods: With IRB approval, ASA I or II patients for elective 1-3 level PSF were randomized to the acute hemodilution (AHD) or control. Control patients donated two units of blood and AHD patients donated one unit preoperatively. For AHD, 400-500cc of blood was removed via the internal jugular vein prior to surgery and reinfused during closure. All patients received the identical anesthetic 70% nitrous oxide, 0.3% isoflurane, fentanyl 1-2 mcg/kg/h and Vecuronium; with deliberate hypotension to mean arterial blood pressure of 50 mmHg using nitroprusside and esmolol. Surgical blood lost was collected, washed in a Hemonetics Cell Saver and returned to the patient. Patients were transfused blood for a hemoglobin of less than 8mg%.

Results: Patients in the AHD started the procedure and were discharged from the hospital with higher hematocrits than the control patients, despite receiving less stored blood. Only 17% (3/17) of the AHD patients required the transfusion of autologous blood compared to 67% (12/18) of the control patients. Two of the control patients also received allogenic blood (for hematocrits of 22 & 24mg%). There was no significant difference between the two groups for blood loss or cell saver reinfusion.

Conclusion: Acute normovolemic hemodilution should reduce the need for preoperative autologous donations for 1-3 level PSFs.

1: Hematocrit preoperatively, immediately postoperatively, and on postoperative day 1.
2: Number of patients transfused with either autologous or allogenic blood.