Locoregional intravenous anesthesia

Abstract

To analyse current data on intravenous regional anaesthesia (IVRA), its benefits and drawbacks. Articles were obtained from a Medline search using the following search terms: 'intravenous regional anaesthesia', alone or combined with 'local anaesthetic agents', 'toxicity'. Following articles in English and in French have been selected: main articles, original articles, update and review articles, letters to the editor and recent editorials. Physiopathological and pharmacological data were extracted for involved mechanisms and means for improving this technique. IVRA is a reliable and efficient technique with a lower cost than general anaesthesia and well adapted for limb surgery in the ambulatory patient. Depending on the site of the surgical field, the pneumatic tourniquet is set either on the arm, forearm or wrist for the upper limb or thigh, calf or ankle for the lower limb. When set in periphery, less local anaesthetic agent is required. A wide tourniquet requires a lower inflation pressure than a double cuff tourniquet. A single cuff is as efficient as a dual cuff if shape, size and inflating pressure are appropriate. The limb occlusion pressure (LOP) is the minimal pressure required to occlude blood flow. It is assessed with either a pulse oximeter or Doppler for determination of the lowest cuff inflating pressure. The cuff is inflated to 50 mmHg above LOP. Oozing in the surgical field can be decreased by the re-exsanguination technique. Currently, lidocaine is the only local anaesthetic released in France for IVRA. Addition of a muscle relaxant, a NSAID or clonidine allows the dose of local anaesthetic agent to be decreased and improves postoperative analgesia.