• Intravenous regional anesthesia (IVRA) or Bier block anesthesia is an anesthetic technique that can be used for surgery of the distal part of the thoracic and pelvic limbs. The technique usually involves exsanguination, which forces blood out of the extremity, followed by the application of a tourniquet to stop blood flow. Local anesthetic is then injected intravenously.
• Because of cats' temperament IVRA is normally performed under general anesthesia General anesthesia: overview or sedation Sedation or sedative protocol.

Uses

• Useful for producing intraoperative antinociception and decrease the amount of volatile anesthetic necessary to maintain anesthesia.
• Useful for foot surgery since torniquet reduces hemorrhage at surgical site.
• Useful for biopsies, removal of foreign body from paw.
• Useful for animals with systemic disease which would complicate general anesthesia.
• Does not distort surgical site.

Advantages

• Reliable intraoperative antinociception.
• Simple to perform.
• Cheap equipment required.

Disadvantages

• If inadequately sedated or restrained animal may move during procedure (IVRA associated with light general anesthesia should therefore be preferred).
• Must identify limit of anesthetized area before operating.
• Prolonged tourniquet placement can produce pain and ischemia.
• No postoperative analgesia.

Alternative techniques

• Peripheral nerve blocks Anesthesia: peripheral nerve block - pelvic limb  Anesthesia: peripheral nerve block - thoracic limb.
• General anesthesia with systemic analgesia.

Time required

Preparation

• A few minutes to gather equipment.

Procedure

• A few minutes to administer local anesthesia.

Decision taking

Criteria for choosing test

• Assess nature of surgery and temperament of animal.

Risk assessment

• The clinician should assess if performing IVRA in a non-sedated (or unsedated) animal or in a sedated or anesthetized animal depending on type and duration of the surgery, animal's demeanour and clinical conditions.