Production of free radicals measured by spin trapping during operations for stenosis of the carotid artery

Objectives: To analyse production of free radicals during operations for st enosis of the internal carotid artery. Settings: University hospital, Sweden. Subjects: 10 patients operated on for carotid artery stenosis. Interventions: Blood samples were repeatedly drawn from the sigmoid sinus t hrough a catheter in the internal jugular vein on the same side, before, du ring, and after clamping of the internal carotid artery. OXANOH was added t o the blood samples in vitro and the radical production calculated from the amount oxidised to OXANO as electron spin resonance. Main outcome measures: The relation between radical production and certain clinical variables investigated by partial least squares regression analysi s. Results. There were several significant relations. High systolic blood pres sure and advanced age were associated with low, and severe degree of stenos is with increased, free radical production. Certain anaesthetic drugs as we ll as blood variables also influenced the production of radicals. Conclusions: The technique used seems to offer the possibility to find and study methods to reduce free radical production during this kind of operati on.