The effect of vitamin C on hemodynamics and arterial blood gas in tourniquet induced ischemia-reperfusion injury during unilateral total knee replacement in elderly patients

ABSTRACT

BACKGROUND: Free radicals, such as reactive oxygen species which are released abruptly after deflation of an ischemic tourniquet, cause reperfusion injuries. Vitamin C produce cytoprotective effects due to reduction of free radicals. This study was designed to investigate the effect of vitamin C on hemodynamics and arterial blood gas during unilateral total knee replacement. METHODS: In the vitamin C group (VC group N = 19), patients were administrated with vitamin Ca priming bolus of vitamin C 0.06 g/kg mixed with 100 ml saline infused for 20 min at 10 min before deflation of tourniquet, followed by vitamin C 0.02 g/kg mixed with 30 ml saline at 0.5 ml/min. In the control group (control group N = 15), patients were infused by 100 ml saline. Mean arterial blood pressure, heart rate and arterial blood gas were measured at 20 min after anesthesia induction, just before deflation, 5 min after deflation and 20 min after deflation of tourniquet. RESULTS: Mean arterial blood pressure in the VC group was maintained higher than control group at 1 min after deflation of the tourniquet. Arterial O2 tension and saturation in the VC group were higher than control group at 5 min and 20 min after deflation of the tourniquet. CONCLUSIONS: We concluded that the administration of vitamin C during total knee replacement could inhibit decline of mean arterial blood pressure and arterial oxygenation induced by ischemiareperfusion significantly.