Autologous Blood Recovery Combined With Controlled Hypotension Reduced Blood Transfusion And Oxygenation And Lactate Metabolism In Brain Tissue

Objective:To observe the effects of blood salvage and controlled hypotension which can reduce allogeneic blood transfusion on brain tissue oxygenation and lactic acid metabolism in patients with spinal surgery, and to determine the efficacy and safety of combination.Methods:Sixty patients scheduled for spinal surgery with ASA grade I-II levels in our hospital from December2011to May2013were randomly divided into two groups with30cases in each:Experimental Group (blood salvage combing controlled hypotension) or Control Group. General anesthesia was chosen in all patients. Blood samples were taken from the right jugular bulb and radial arterial simultaneously before surgery (T0),the end of surgery(T2) and24hours after surgery (T3) for blood gas analysis. Arterial oxygen partial pressure (PaO2),arterial oxygen saturation degree (SaO2),jugular bulb blood oxygen partial pressure (PjvO2),jugular bulb oxygen saturation (SjvO2), arterial and venous blood lactic acid (LacA, Lacjv) were recorded. Cerebral arterial oxygen content (CaO2), jugular bulb oxygen content (CjvO2),cerebral oxygen consumption C (ajv) O2, cerebral oxygen uptake rate (CERO2) and difference in arterial and venous lactic acid content (ADVL) were calculated according to Fick formula. T1is the stable point of intraoperative controlled hypotension. Patients’ infusion volume、blood loss、autologous blood transfusion、allogeneic blood transfusion and the hemoglobin levels were recorded at each time point of these two groups.Results:There was no significant difference in age, body weight, heart rate (HR), preoperative hemoglobin level (Hb) and preoperative coagulation index between two groups(P>0.05).Allogeneic blood transfusion volumes were significantly less in Experimental Group than those in Control Croup (P<0.01). Hb at the end of surgery(T2) and24hours after surgery (T3) in Experimental Group were significantly higher than those in Control Group (P<0.01). Before surgery (TO), The CaO2, CjvO2, CERO2and ADVL of the two groups had no statistical difference (P>0.05). The CaO2, CjvO2decreased significantly at the end of surgery(T2) and24hours after surgery (T3)compared with TO (P <0.05or P<0.01) in two groups. The decrease of CaO2, CjvO2was significantly more in Control Group than those in Experimental Group at T2, T3point (P<0.01). CERO2was significantly lower at T2, T3point than at TO in Experimental Group(P<0.01), while CERO2was significantly higher in Control Group than at TO in Experimental Group(P<0.01). ADVL had no significant differences at every point between these two groups (P>0.05). Blood pressure was significantly lower in Control Group(64.0±5.4mmHg) than those in Experimental Group(80.7±4.5mmHg) during operation by application of nitroglycerin.Conclusion:Combining autologous transfusion with controlled hypotension during spinal surgery can significantly reduce allogeneic blood transfusion and improve the brain tissue oxygenation, and have no influence on lactate metabolism.