Intravenous regional anaesthesia (IVRA)

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Last modified 24/02/2015

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CHAPTER 5 Intravenous regional anaesthesia (IVRA)

Bier block of upper limb

Intravenous regional anaesthesia (IVRA) is a simple and effective regional anaesthesia technique for painful procedures on the forearm, wrist and hand (e.g. for the reduction of a distal radius fracture). IVRA produces anaesthesia by direct diffusion of the local anaesthetic from the veins into the adjacent nerves. The main advantages of this technique are its simplicity and reliability. Its disadvantages are the lack of lasting analgesia (the block resolves almost immediately after the release of the tourniquet), the time required for preparation and performance of the block, and the obligatory delay before the cuff can safely be deflated. It is more effective (with less pain and a better reduction) than a haematoma block for the reduction of distal radius fractures and is somewhat simpler than other regional anaesthesia techniques. IVRA is only appropriate for short procedures of less than 45 minutes before tourniquet discomfort becomes intolerable.

Preparation

• Check the equipment: a proper theatre tourniquet system is ideal but an ordinary blood pressure cuff may be used if an assistant is available to keep it inflated to the correct pressure. Check that the cuff is the correct size required and has no leaks.

• Insert an intravenous line on the uninjured limb and ensure that resuscitation medications and equipment are available.

• Insert a small IV cannula (22G) into the hand of the injured limb, through which the local anaesthetic will be administered.

• Administer procedural sedation if required.

• The patient should be in the supine position with the injured arm elevated for 1 to 2 minutes to achieve passive emptying of the veins.

• Prepare the local anaesthetic agent to the required dilution, and calculate the maximum permissible dose for the patient’s body weight and general condition. Use only an intravenous formulation of lidocaine. Bupivacaine and ropivacaine are not suitable agents for IVRA.