Intravenous Regional Anesthesia (Bier Block)

Indications

• Intravenous regional anesthesia (IVRA) is a simple technique of providing anesthesia for short surgeries on the upper or lower extremities. It involves the intravenous injection of large volumes of a dilute local anesthetic into an extremity where the circulation is impaired by a tourniquet.^1-4
• IVRA, also known as Bier block, was named after August Bier, who first described this technique in the early 1900s.³
• Indications for IVRA include:
  • Surgical procedures involving the upper or lower extremity that is anticipated to last 1 hour or less. Examples include ganglionectomy, carpal tunnel release, fracture reduction, and contracture release/surgery, laceration repair, burn debridement, etc.
  • Patients who would not tolerate or want general anesthesia.

Anatomy and Clinical Correlates

• Pertinent anatomy is knowing the location and distribution of veins within the hand, arm, or leg before placing this block.
• Tourniquet pain and tourniquet time restrict the clinical utility of using IVRA.^1-5
• There is poor postoperative analgesia unless adjuncts are added. Therefore, IVRA is not an ideal choice for surgeries with significant postoperative pain.^1-5
• The mechanism of action of IVRA involves the diffusion of the local anesthetic outside the vasculature, leading to the saturation of nerve endings within the tissue and blockade of nerve conduction propagation.

Contraindications

Absolute Contraindications^3,4

• Patient refusal
• Allergic reaction to amide local anesthetics particularly lidocaine or prilocaine
• Impaired perfusion of the limb
• Deep vein thrombosis or thrombophlebitis of the limb
• Extremity cannot be completely exsanguinated
• Extremity with an open wound

Relative Contraindications^3,4

• Crush injury of an extremity
• Inability to locate peripheral veins
• Local skin infections, cellulitis
• Compound fractures, severe vascular injuries
• Arteriovenous shunts
• Sickle cell disease
• Surgery planned for >1 hour
• Poorly controlled diabetes, etc.

Equipment and Materials

• Sterile skin prep (alcohol or chlorhexidine)
• One small gauge PIV catheter (20, 22 or 24 gauge)
• One Esmarch bandage to exsanguinate the upper or lower extremity
• One double-cuffed pneumatic tourniquet
• One 30 or 50 mL Luer lock syringe
• Standard American Society of Anesthesiologists monitors
• Medication options:
  • Lidocaine 0.5% is commonly used, staying below the toxic range of 2.5mg/kg. Preservative-free without epinephrine.
    • Fast onset: 4-5 minutes
    • Recommended dosing 30-40 mL
  • Prilocaine 0.5% (not available in the United States)
  • Bupivacaine should not be used for IVRA due to risk of cardiotoxicity and potential for cardiac arrest.
  • Several adjuncts can be added to the local anesthetic injection.⁵
    • Alpha2 agonists – Clonidine and dexmedetomidine
      • Clonidine (1-2 mcg/kg) may prolong tourniquet tolerance and may add postoperative pain control.
      • Dexmedetomidine (0.5-1 mcg/kg) provides a more rapid onset of sensory and motor blockade and prolonged sensory and motor blockade recovery. Improved postoperative pain
    • Ketamine may help with pain control and add postoperative analgesia.
    • Ketorolac can lessen tourniquet pain and may provide postoperative analgesia.
    • Dexamethasone (8 mg) has been shown to fasten onset and help with tourniquet pain and postoperative pain.
    • Opioids have also been shown to fasten the onset of blockade and help with tourniquet tolerance.
    • Other adjuncts less frequently used are magnesium and nitroglycerin, which have shown to reduce tourniquet pain and decrease postoperative pain.

Technique

• The patient should be placed in the supine position with easy access to the upper or lower extremity in preparation for PIV catheter placement.
• Vein selection depends on the surgical site.
  • Procedures in the hand: vein in the dorsum of the hand
  • Procedures in the elbow: vein in the forearm or antecubital fossa
  • Procedures in the lower extremity: vein of the foot, ankle, or lower leg
• Local anesthetic selection:
  • Lidocaine 0.5% or prilocaine 0.5%
• A sterile PIV catheter is placed in the extremity of interest and secured.
• A double pneumatic tourniquet is placed with the proximal cuff high on the extremity.
• The extremity is then elevated to allow for passive exsanguination (~3 minutes).
• A rubber Esmarch bandage is wrapped around the extremity from the most distal to proximal portion of the extremity to aid in exsanguination.
• The axillary artery is occluded with manual pressure.
• The proximal cuff is first inflated 50-100 mm Hg above the systolic blood pressure (typically 250 mm Hg).
• The Esmarch bandage is then removed.
• 30-50 mL of local anesthetic is injected via the PIV catheter.
• The local anesthetic is injected slowly over 1-2 minutes to avoid possible leakage. Analgesia is typically observed within 5-10 minutes.
• For forearm surgery, a forearm tourniquet with 12-15 mL of 2% lidocaine has been proposed.⁷
• The PIV catheter is then removed.
• The distal cuff is inflated, and the proximal cuff is deflated after the onset of anesthesia or when the patient notes tourniquet pain (typically within 20-30 minutes).
• Skin blanching and patient reporting numbness, paresthesia, and heat indicate a successful block.
• It is important to note that the tourniquet should not be deflated until at least 20 minutes after the injection of the local anesthetic.⁶
• Between 20 and 40 minutes, a cycled deflation technique should be used (deflation for 5 seconds → reinflation for 1 minute → deflation for 5 more seconds → reinflation for 1 more minute → deflation).
• For surgeries lasting more than 40 minutes, the tourniquet can be deflated without cycling.⁶

Caution and Complications

• The Bier block is typically a low-risk procedure with few reported complications.⁸
• Major complications include local anesthetic systemic toxicity (LAST). Therefore, tourniquet pressure should be maintained for a minimum of 30 minutes postinjection.
• Other reported complications include nerve damage, compartment syndrome, thrombophlebitis, and venous congestion of the limb.⁸
• Things to pay attention to with IVRA include:
  • Premature cuff deflation
  • Inadequate tourniquet pressure
  • Infiltrated PIV