THE EFFECT OF EPIDURAL-ANESTHESIA ON PERIPHERAL RESISTANCE AND GRAFT FLOW FOLLOWING FEMORODISTAL RECONSTRUCTION

Objective: To determine the extent to which epidural anaesthesia influ ences peripheral resistance and graft blood flow following femorocrura l reconstruction. Design: Prospective, controlled study measuring bloo d flow, arterial pressure and peripheral resistance in femorocrural by pass grafts for 20 min following onset of epidural anaesthesia with 15 ml of 0.25% bupivacaine. Patients: Twenty patients undergoing femorocr ural reconstruction for critical lower-limb ischaemia with in situ lon g saphenous vein, under general anaesthesia. Ten patients had epidural cannulae inserted preoperatively and injected with bupivacaine after completion of the graft. Results: Peripheral resistance fell in all 10 patients receiving epidural anaesthesia from a mean (range) of 1.07 P RU (0.32-2.2) to 0.49 PRU (0.19-0.72), compared to control values of 0 .95 PRU (0.39-2.0) to 0.91 PRU (0.41-1.51; P < 0.01, Wilcoxon). There was a tendency for blood pressure to fall in the study patients (not s ignificant) but graft blood flow still increased from 98 ml min(-1) (4 1-221) to 160 ml min(-1) (101-250), compared to flow in the control pa tients of 101 ml min(-1) (45-176) at baseline to 104 ml min(-1) (56-16 8; p < 0.01) at 20 min. Conclusions: Epidural anaesthesia significantl y decreases peripheral resistance and increases graft blood flow in fe morocrural grafts and would appear, therefore, to be of benefit for pa tients undergoing femorodistal reconstruction.