Intravenous Regional Anesthesia (aka: A Bier Block)
Use: Fractures/Dislocations/Complex Wounds of the mid-distal upper (or lower) extremity.
Procedures that take <60minutes.
- An IV or butterfly is placed in the hand of the affected limb. Use a small gauge needle.
- The upper arm is wrapped with cast felt padding (optional) before the application of a manual BP cuff.
- Ensure no cuff leak prior to performing.
- A 0.5% solution of lidocaine is used at a dose of 1.5-3mg/kg- drawn into a 60cc syringe.
- For a 70kg adult this comes out to 20-40cc of 0.5% lidocaine (WITHOUT EPI).
- If 0.5% is not available, use 10-20cc of 1% lidocaine diluted with equal parts saline.
- Elevate the arm for 1-2 minutes and ‘strip’ the veins of blood to attempt to exsanguinate the limb.
- In the OR, a tight rubber bandage (esmarch bandage) is circumferentially applied proximal to distally to achieve this- difficult to do in an acutely injured limb and not needed.
- Inflate the BP cuff to 100mHg over the patients SBP while the arm is elevated.
- Inject the entire anesthetic solution by slow IVP into the angiocath/butterfly with the cuff inflated.
- Patient will begin to complain of tingling and a warm or cold feeling and the skin will become mottled.
- Can remove the IV/butterfly at this point.
- Wait 5-10 minutes. The limb should now be entirely anesthetic distal to the BP cuff.
- Ensure that the cuff stays >100 above systolic. May need to clamp cuff or re-inflate on occasion to maintain tourniquet effect.
- The cuff is deflated using a “deflation/re-inflation” technique to reduce the risk of a significant IV bolus of lidocaine reaching the central circulation, whereby for 3 cycles the cuff is deflated for 5 seconds and then re-inflated for 1 minute. (Dr. Reeve says this is not needed). Some authors recommend maintaining tourniquet for a minimum of 30 minutes to prevent significant bolus of lidocaine into central circulation.
Recall toxic dose of lidocaine without epi is 5mg/kg (70kg adult= 350mg (35ml) (Lidocaine with epi=7mg/kg)