A preliminary study to assess neutrophil and endothelial response to knee arthroplasty with the use of a tourniquet : effects of spinal or sevoflurane anesthesia

Background : During orthopedic surgery, the use of a pneumatic tourniquet results in side effects secondary to ischemia-reperfusion phenomena. We tested the hypothesis that total knee arthroplasty with a tourniquet is associated with increase in plasma concentrations of biomarkers of neutrophil activation and endothelial injury. The second aim was to compare these changes during spinal or general inhalational anesthesia. Methods : 40 adult ASA I-II patients scheduled for total knee arthroplasty with a tourniquet under spinal or sevoflurane anesthesia were included. Venous blood samples were collected before surgery, 1 h, 3 h, and 24 h after tourniquet deflation. To assess neutrophil activation, plasma concentrations of total and active fractions of myeloperoxidase, as well as elastase concentrations and proteolytic activity were measured. Endothelial injury was assessed by measurement of plasma concentrations of syndecan-1, soluble thrombomodulin, soluble E-selectin, and vascular endothelial growth factor. Results were analyzed with a two-way analysis of variance. P< 0.05 was considered statistically significant. Results : Plasma concentrations of active but not total myeloperoxidase and elastase significantly increased following tourniquet deflation. The level of syndecan-1, soluble thrombomodulin, soluble E-selectin, but not vascular endothelial growth factor, significantly decreased postoperatively. These changes of biomarkers were similar during spinal and sevoflurane anesthesia. Conclusions : Total knee arthroplasty with pneumatic tourniquet is associated with systemic release of markers of neutrophil activation which was comparable during spinal or sevoflurane anesthesia. Systemic expression of endothelial injury was not detected in our clinical conditions.