Plasma catecholamine concentration during and after aorto-femoral bypass grafting

Mean arterial plasma concentration of norepinephrine and epinephrine [NE + E], increased from 2.84 nM (post-induction) to 7.50 nM at the end of an approximately 4-hour operation for aortofemoral bypass grafting (plus unilateral lumbar sympathectomy) in 13 men. It increased to 18.25 nM during the first hour of recovery, and fell to 9.58 nM by the next morning. Thus during recovery, arterial [NE + E], by exceeding the minimum of 10.6 nM [NE] necessary for vasoconstriction, is a probable contributor to postoperative vasospasm as previously hypothesized.