Anaesthesia for vascular surgery on extremities

Patients with lower limb ischaemia present a significant challenge to the anaesthetist because of their widespread vascular disease, which is often asymptomatic, but which leads to a mortality of 12% per year, even without surgery. Lower limb revascularization procedures can be performed with either general or regional anaesthesia, and the type of anaesthetic chosen has no impact on perioperative mortality and only a small effect on the outcome of the bypass procedure. Use of regional anaesthesia in these patients may be associated with a greater than usual risk of epidural haematoma because of the preoperative use of aspirin, clopidogrel and low molecular weight heparin, and the intraoperative use of intravenous heparin. Whatever the technique used, prolonged surgery in a patient with severe cardiovascular disease requires close monitoring, often including arterial and central venous catheters, with careful management of fluid balance, and cardiovascular and coagulation status. Anaesthesia for the acutely ischaemic lower limb is challenging because of inadequate time to evaluate and treat comorbidities and the physiological disturbances resulting from an ischaemic limb. Local anaesthesia with invasive monitoring by an anaesthetist is the preferred technique for embolectomy, but progression to revascularization may still require general anaesthesia. Vascular surgery of the upper limb may include first rib resection for thoracic outlet syndrome (a procedure potentially associated with significant blood loss) and thoracoscopic sympathectomy for hyperhidrosis of the upper limb, which requires appropriate airway management to facilitate lung collapse and insufflation of carbon dioxide into the pleural space.