Bier block

Bier block

Anesthesia type	Regional
Airway	None
Lines and access	PIV
Monitors	EKG
Primary anesthetic considerations
Preoperative
Intraoperative
Postoperative	Local anesthetic systemic toxicity
Article quality
Editor rating	Comprehensive
User likes	0

A Bier block, also referred to as intravenous regional anesthesia (IVRA), is a form of short-term anesthesia and analgesia used for procedures on extremities. The technique consists of applying a tourniquet on the extremity of interest followed by high-volume intravenous injection of low-concentration local anesthesia. This approach provides extremity analgesia without the need for general anesthesia or much additional equipment.

Overview

Intravenous regional anesthesia (IVRA), developed by Dr. August Klaus Bier in 1908, is a form of analgesia for extremity procedures that are expected to last only a short duration.

Because of its relative simplicity and minimal resource requirements, it is an approach used in emergency departments, in the outpatient setting, or in limited-resource medical settings. A large limitation regarding IVRA approaches is tourniquet pain.

Indications

Intravenous regional anesthesia (IVRA) can be considered for surgical procedures on the upper or lower extremity that are anticipated to last 2 hours or less. Typical procedures that may utilize IVRA include laceration repairs, burn debridements, fracture reductions, neuroma excisions, or carpal tunnel release. In general, IVRA can be considered for patients who would not tolerate general anesthesia, when the provider wants to avoid potential complications of other forms of regional anesthesia, or in resource-limited medical settings. IVRA's utility in the context of Complex Regional Pain Syndrome (CRPS) is currently unclear. Though multiple studies have endorsed IVRA in treating CRPS, a 2010 literature review grading the treatment effects for CRPS Type I did not find evidence of IVRA providing consistent benefits to patients.

Given the limited duration of analgesia post-operatively, IVRA is not classically used for management of post-operation pain.

Contraindications

Absolute contraindications:

• Open wounds, sores, or active soft tissue infections in the extremity of interest
• Hypersensitivity/allergy to local anesthetics
• Poor baseline limb perfusion in the extremity of interest, such as those with scleroderma or ischemic vascular disease
• Active deep vein thrombosis or thrombophlebitis
• Poorly controlled hypertension
• Contraindications to tourniquet use (ex: sickle cell disease, ischemic vascular disease)

Relative contraindications :

• Uncooperative patient
• Morbid obesity
• Poorly controlled diabetes mellitus
• Paget's disease

Procedure Technique

A small intravenous catheter is inserted as distally as possible in the extremity of interest. A pneumatic tourniquet is then applied to the proximal end of the limb before it is exsanguinated through positioning and use of bandaging. Sometimes, a second tourniquet is placed next to the first tourniquet to minimize tourniquet pain during the procedure. Often, the limb is elevated for about 3 minutes and then wrapped with an Esmarch other elastic bandage. The proximal tourniquet is then inflated to 250-300 mmHg, or 100 mmHg above the patient's systolic blood pressure, and the elastic bandage removed to verify loss of peripheral pulses. Local anesthetic is then slowly injected into the IV catheter over at least 90 seconds to minimize the risk of anesthetic being pushed past the tourniquet and into systemic circulation. An analgesic and paralytic effect is often observed within 5-10 minutes of administration. If a second tourniquet is being used, the distal tourniquet atop the anesthetized tissue is inflated with the proximal tourniquet then being deflated. At least 20-30 minutes after anesthetic administration and after operation completion, the tourniquet is deflated. The patient should be monitored for 30 minutes post-operatively.

Signs of a successful block include skin blanching, patient reported extremity numbness, paresthesias, and a sensation of heat.

Choice of Local Anesthetic

Choice, concentration, and dose of anesthetic depends on whether the procedure is occurring in the upper or lower extremity, and the surface area of the region of interest.

30-50ml of 0.5% lidocaine without epinephrine for a 70kg patient is a common selection for upper extremity blocks, while 150ml of 0.25% lidocaine is commonly used for lower extremity blocks. Prilocaine, ropivicaine, levobupivicaine and chloroprocaine are also used. Though prilocaine is primarily used in Europe due to its potency, lidocaine is the most common agent in the US, as prilocaine is no longer available. Bupivicaine is not a recommended anesthetic given its cardiac toxicity leading to ventricular dysrhythmias. Regardless of the agent, it is important the anesthetic does not have preservatives or epinephrine.

Adjunct Medications

Many agents have been studied as adjunct medications administered in IVRA. Opioids, apart from meperidine, have been found to not increase analgesia or anesthesia. Among NSAIDs, ketorolac, acetylsalicylate, have been found to reduce tourniquet pain.

Potential Complications

Major Adverse Events

Local anesthetic systemic toxicity (LAST) is the primary risk associated with IVRA, with greatest risk during anesthetic injection and tourniquet deflation. LAST often presents as perioral paresthesias, audio-visual disturbances, sudden change in mental status, or with seizures. Premature cuff deflation, inadequate tourniquet pressure, or forceful agent injection could all lead to systemic escape of local anesthetic. Prevention of LAST includes continuous EKG monitoring, maintenance of tourniquet pressure for at least 30 minutes after anesthetic injection, and graded tourniquet deflation. Providers should be prepared to administer intravenous lipid emulsion therapy to rapidly manage any signs of LAST when utilizing IVRA.