LOWER LEG ELECTRICAL-IMPEDANCE AFTER DISTAL BYPASS-SURGERY

Electrical impedance was determined in 13 patients following distal by pass surgery to evaluate lower leg oedema as reflected by its circumfe rence. Tissue injury was assessed by the plasma concentration of muscl e enzymes. After surgery, the volume of the control lower leg increase d from 1250 (816-2373) to 1384 (874-2345) ml (median and range; P<0.05 ), where the impedance did not change significantly from 140 (92-181) ohms. The volume of the operated leg increased more [from 1129 (824-23 73) to 1600 (1090-2837) ml], and the decrease in electrical impedance was also pronounced [137 (125-169) to 83 (69-104) ohms (P<0.001)]. Tis sue injury after surgery was indicated by an increase in total creatin e kinase (n = 17) and MB isoenzyme of creatine kinase (n = 8) (P<0.05) . Myoglobin (n = 8) had increased already during surgery (P<0.05), whe reas there was no significant change in the plasma concentration of tr oponin I (n = 8). In conclusion, tissue injury was reflected by increa ses in muscle enzymes in plasma. We found an inverse correlation betwe en lower leg electrical impedance and volume, but the deviation in ele ctrical impedance was approximately twice that of the leg volume. Elec trical impedance appears to be a useful method for the evaluation of l ower leg oedema after distal bypass surgery.