• Alon P. Winnie, MD

I.	INTRODUCTION
II.	ANATOMY
III.	INDICATIONS
	Upper Extremity
	Lower Extremity
	Pediatrics
IV.	CONTRAINDICATIONS
V.	EQUIPMENT
VI.	PATIENT PREPARATION
VII.	TECHNIQUE
	Upper Extremity IVRA
	Lower Extremity IVRA
VIII.	PHARMACOLOGIC CONSIDERATIONS
	Local Anesthetic Considerations
	Adjuncts to Local Anesthetics for IVRA
	Specific IVRA Treatments for CRPS
IX.	COMPLICATIONS
X.	SUMMARY

INTRODUCTION

The technique of intravenous regional anesthesia (IVRA) was first introduced by August Bier in 1908.¹ Bier block essentially consists of injecting local anesthetic solutions into the venous system of an upper or lower extremity that has been exsanguinated by compression or gravity and that has been isolated by means of a tourniquet from the central circulation. In Dr. Bier’s original technique, the local anesthetic procaine in concentrations of 0.25% to 0.5% was injected through an intravenous cannula, which had been placed between two Esmarch bandages utilized as tourniquets to divide the arm into proximal and distal compartments.^2–4 After injecting the local anesthetic, Dr. Bier noted two distinct types of anesthesia; an almost immediate onset of “direct” anesthesia between the two tourniquets, and then, after a delay of 5 to 7 min, an “indirect” anesthesia distal to the distally placed tourniquet. By performing dissections of the venous system of the upper extremity in cadavers after injecting methylene blue, Bier was able to determine that the direct anesthesia was the result of local anesthesia bathing bare nerve endings in the tissues, whereas the indirect anesthesia was most probably due to local anesthesia being transported to the substance of the nerves via the vasa nervorum, where a typical conduction block occurs. Dr. Bier’s conclusion was that two mechanisms of anesthesia were associated with his technique: peripheral infiltration block and conduction block. The technique, as originally described by Dr. Bier, remains essentially unchanged in modern practice for the past 95 years, except for the introduction of the double-tourniquet preparation used in current clinical practice^5–7 (Figure 41–1).

Figure 41–1. Double pneumatic tourniquet system for use in IV regional anesthesia of the upper or lower extremity.

Bier block can be used for brief surgical procedures or manipulations of the upper or lower extremity. However, the technique found its greatest acceptance for use for the upper extremity because tourniquet problems and other safety issues seem to arise more frequently when IVRA is used on the lower extremities. Bier block is also a procedure that has found utility as a treatment adjunct for patients suffering from complex regional pain syndromes (CRPS) (formerly know as reflex sympathetic dystrophy, or sympathetically maintained pain) as an alternative to repeated sympathetic blocks. In this regard, IVRA has been shown to decrease neurogenic inflammation, a phenomenon possibly associated with CRPS, with little impairment of sensory function, at least when mepivacaine is the local anesthetic chosen for the block. Sensibility to cold is significantly decreased 10 and 30 min after the block, even with a reduction in the skin temperature on the blocked side.⁸ Chemical sympathectomy using IVRA with agents such as guanethidine or bretylium may last up to 5 days, as compared with local anesthetic blocks, which typically provide analgesia lasting only several hours. Quantitative sensory testing before and after such blocks has demonstrated that it is possible to predict which patients will have long-lasting pain alleviation using IVRA guanethidine blocks following traumatic injury or surgery.⁹

Although IVRA is a safe and effective method of administering local anesthetics for extremity block both for surgery and for pain control, one recent large survey noted that most third-year (CA-3) anesthesia residents had performed fewer than 10 such blocks during the entire course of their training.¹⁰

ANATOMY

The only relevant anatomy is the location and distribution of the veins of the hand, antecubital fossa, and of the foot and ankle region.

INDICATIONS

Upper Extremity

IVRA is appropriate for surgeries and manipulations of the extremities requiring anesthesia of up to an hour’s duration. It is most suited for peripheral, soft-tissue operations such as ganglionectomies, carpal tunnel release, Dupuytrens contractures, or reduction of fractures. However, the necessity of exsanguinating the extremity using an Esmarch bandage, a potentially painful maneuver, may preclude certain procedures from being undertaken with this technique (see Figures 41–5, 41–6, and 41–10). Likewise, manipulations of the ulnar, median, or radial nerves may cause paresthesias, which may require the use of analgesics or sedatives. A novel use of IVRA is for anesthetizing the hand prior to injecting botulinum toxin A (BTX-A) for the treatment of hyperhidrosis. BTX-A significantly reduces sweat production, as measured by Minor’s test and as quantified by corneometer analysis, but the injection is painful unless the hand is anesthetized beforehand; IVRA has been found to be very suitable for this purpose.¹¹ IVRA of the upper extremity has been occasionally utilized for prolonged analgesia/anesthesia, with a mandatory tourniquet deflation period of at least 1 min prior to reestablishing the anesthetized state.¹²

Lower Extremity

IVRA may be used for brief surgical interventions of the lower extremity in a manner analogous to that described earlier for upper extremity surgery. Surgical procedures that may be completed using this approach include excision of a mass, digital nerve repair, phalangeal fracture/dislocation surgery, and accessory navicular excision. Any foot, ankle, or distal lower extremity orthopedic procedure requiring approximately 45 min or less may be amenable to this modality. Although IVRA has been associated with an increased incidence of compartment syndrome when treating tibial shaft fractures, and has therefore been deemed contraindicated in such cases, a recent study in volunteers showed no significant difference in tissue pressures before and after tourniquet inflation regardless of the volume of saline used (≤1.5 mL/kg) or as a function of time following saline injection during tourniquet inflation. The authors concluded that in the normal atraumatic limb, simulated IVRA using normal saline (NS) does not increase tissue pressure within the anterior compartment of the leg.¹³

Clinical Pearls

IVRA for the lower extremity has been associated with an increased incidence of compartment syndrome when treating tibial shaft fractures. Although not proven, it is suggested that IVRA be used with caution in these patients.

Some patients, especially with painful fractures of the extremities, may not be able to tolerate the placement of the Esmarch bandage with subsequent exsanguination of the leg (or arm). If simply elevating the extremity is not sufficient to effect this process, and IVRA is still considered the technique of choice, then exsanguination maybe painlessly but effectively accomplished using a zippered pneumatic splint.¹⁴ The leg (or arm) is placed on the open splint, after which the splint zipper is closed. The splint is then inflated to a pressure well above arterial pressure, after which time the proximal cuff is inflated, and the splint is deflated and removed. Whereas applying an Esmarch bandage to a painful fracture produces excessive pain, as the pressure is increased gradually in the pneumatic splint, the fracture usually becomes more comfortable, and this, of course improves the likelihood of the patient accepting the technique and hence enhances the chance for success with IVRA.

Pediatrics

IVRA has been an acceptable choice in selected pediatric patients for the reduction of fractures of the upper extremity. One large study of 470 children ages 2–19 years found that IVRA was adequate for fracture reduction in 99% (467 total). No complications were noted. The technique was only aborted in three children due to failure to gain peripheral venous access.¹⁵ However, the technique of IVRA was found not to be superior to administration of nitrous oxide for the same purpose in a smaller sample of 28 children. Additionally, the nitrous oxide use was more rapidly applicable and dissipated more readily.¹⁶

CONTRAINDICATIONS

The only absolute contraindication to IVRA is patient refusal. Relative contraindications include:

• Crush injuries of an extremity

• Inability to locate peripheral veins

• Local skin infections

• Cellulitis

• Compound fractures

• Patients with convincing history of allergy to local anesthetics

• Patients with severe vascular injuries to the extremity

• Preexisting vascular arteriovenous shunts and patients in whom a tourniquet is unsuitable (ie, patients with severe peripheral vascular disease)

Clinical Pearls

Bier block is an acceptable form of regional anesthesia in the anticoagulated patient.

The feasibility of using a pneumatic tourniquet in those diagnosed with sickle cell disease must be balanced against the need for performing this type of anesthesia. Tourniquet use in this instance may induce localized stasis of blood, acidosis, and hypoxemia, with the subsequent formation of sickle cells. On the other hand, for lower extremity procedures in which regional block is considered preferable in the sickle cell patient, spinal or epidural block may result in compensatory vasoconstriction and a decreased Pao2 in the nonblocked areas, making these areas possible sites for infarction. Under these circumstances, IVRA may actually be less offending than central neuraxial block.

EQUIPMENT

(Figures 41–1 through 41–11)

1. Local anesthetic agents: Lidocaine HCl, 0.25–0.5% (alternative is prilocaine, 0.5%)

2. One rubber tourniquet (Penrose drain) 12–18 in. in length (30–45 cm) and ⅞in· wide (2.3 cm) for use prior to placing the intravenous cannula (see Figures 41–7 and 41–11)

3. One 18- or 20-gauge intravenous (IV) extracatheter (catheter-over-needle) (see Figures 41–2 and 41–11)

4. One 500-mL or 1-L bag of IV solution connected to an infusion set (vs a Hep-Lock) to be connected to the IV cannula to maintain its patency until the anesthetic solution is injected in the isolated extremity (may substitute a saline-flushed IV port instead)

5. Standard American Society of Anesthesiologists (ASA) monitors (electrocardiograph, blood pressure, pulse oximeter)

6. Resuscitation equipment (IV catheter, crystalloid solution, and infusion set for the contralateral upper extremity) (for upper extremity IVRA)

7. A functional IV catheter, crystalloid solution, and infusion set for the contralateral upper extremity

8. Two pneumatic tourniquets of appropriate size for the selected extremity (see Figures 41–1,41–3 through 41–6, 41–9, and 41–10)

9. One Esmarch bandage 60 in. in length (152 cm) and 4 in. wide (10 cm) for exsanguinating the arm (see Figures 41–5, 41–6, and 41–10)

10. Sterile skin preparatory set

11. Fifty-milliliter Luer-Lok syringe (see Figures 41–7 and 41–11)

12. One graduated measuring cup for the mixing of solution, preferably with a 100-mL capacity

13. Adhesive tape; various sizes

Figure 41–2. Intravenous cannula and Hep-Lock placed in a distal vein of the hand in preparation for IVRA.

Figure 41–3. Placement of a proximal and distal tourniquet of the double pneumatic tourniquet system on the left upper extremity in preparation for IVRA.

Figure 41–4. Double pneumatic tourniquet system on the left upper extremity; IV access port on the left hand; 50-mL syringe loaded with local anesthetic.

Figure 41–5. Beginning of the exsanguination process of the left upper extremity using a tightly wrapped Esmarch bandage from the distal hand to the proximal upper extremity at the base of the distal tourniquet.

Figure 41–6. Completion of the exsanguination process of the left upper extremity with demonstration of the Esmarch bandage wrapped from distal to proximal.

Figure 41–7. Injection of the local anesthetic through the left hand intravenous access port. Note the peripherally placed elastic tourniquet used to encourage distal and minimize proximal flow of the local anesthetic.

Figure 41–8. Removal of the left hand IV access port and application of Betadine-soaked sponge pad.

Figure 41–9. The right lower extremity prepared for IVRA. The double pneumatic tourniquets are in place, the leg is elevated on a bolster, and the IV access port is visible on the distal foot.

Figure 41–10. The right lower extremity is wrapped with a tightly wound Esmarch bandage in preparation for exsanguination by the proximal tourniquet.

Figure 41–11. Injection of the local anesthetic through a distally placed peripheral IV access port on the dorsum of the right foot. Note the placement of the distal elastic tourniquet to promote distal and minimize proximal spread of the local anesthetic.

Clinical Pearls

Adjuvants to local anesthetics: There is some evidence suggesting that ketorolac, clonidine, and certain muscle relaxants may have efficacy as adjuvants. These include fentanyl citrate, pancuronium bromide, rocuronium, D-tubocurarine, ketorolac, sodium bicarbonate, and clonidine.

PATIENT PREPARATION

The patient lies in the dorsal recumbent position or in any other position as long as the vein selected for placement is readily accessible. The resuscitative equipment is checked, and the pneumatic tourniquets are tested and prepared for use. For surgery on the elbow, the needle will be placed in the forearm or antecubital fossa. For procedures on the hand or forearm, a vein on the dorsum of the hand is best selected (see Figure 41–2).

Clinical Pearls

Some authors have demonstrated excellent results for hand surgery when placing the IV port either on the distal forearm¹⁷ or in the antecubital fossa.¹⁸ Therefore, when a patient having surgery on the distal extremity presents with difficult venous access on the hand, using a vein in the antecubital fossa should be considered instead.

For lower extremity procedures, a vein in the foot, ankle, or lower leg is chosen (see Figure 41–11). After obtaining intravenous access in a nonoperated extremity (alternatively, a central venous access maybe secured), a full complement of ASA monitors is applied and baseline vital signs are assessed. If the patient is in severe pain, small aliquots of IV analgesics may now be administered (ie, fentanyl 1–2 mcg/kg) to facilitate the exsanguination process. Since total patient cooperation is not essential to be successful, small doses of a water-soluble benzodiazepine (ie, midazolam 15–25 mcg/kg) may alternatively be administered for anxiolysis. An important benefit to choosing a benzodiazepine is the suppression of the convulsant response associated with local anesthetic toxicity, a valid concern in the patient undergoing IVRA due to the large volume of agent being directly administered into the vascular system.

TECHNIQUE

Upper Extremity IVRA

The following is the technique of IVRA for upper extremity procedures as previously taught at Cook County Hospital by Alon R Winnie, MD.

1. A double pneumatic tourniquet is placed on the proximal cuff high on the upper arm (see Figures 41–3 through 41–6)

2. An indwelling plastic extracatheter is inserted into a peripheral vein as far distally as feasible.

3. The entire arm is elevated, and a rubber Esmarch bandage is wound around the arm spirally from the hand to the distal cuff of the double tourniquet to exsanguinate the arm (see Figures 41–5 and 41–6).

4. The axillary artery is digitally occluded, and while pressure is maintained on it, the proximal pneumatic cuff is inflated to 50–100 mm Hg above the systolic arterial blood pressure, after which time the Esmarch bandage is removed.

5. Following inflation of the proximal cuff and removal of the Esmarch bandage, 30–50 mL of 0.5% lidocaine HC1 is injected via the indwelling plastic catheter, the volume depending on the size of the arm being anesthetized (see Figure 41–7).

6. After injection of the local anesthetic, the arm is brought down to the level of the procedure table, the IV cannula in the surgical extremity is withdrawn, and pressure is quickly applied over the site using sterile povidone-iodine (Betadine)-soaked sponges (see Figure 41–8).

7. About 25–30 min after the onset of anesthesia or when a patient complains of tourniquet pain, the distal cuff is inflated and the proximal cuff is deflated, to minimize the development of tourniquet pain.

Clinical Pearls

Compression of the axillary artery both before and during inflation of the pneumatic tourniquet is important, since as the pressure in the tourniquet rises, venous outflow is prevented before arterial inflow; and therefore, without occlusion of arterial inflow, exsanguination of the extremity may be incomplete. In fact, one study showed that arm elevation and arterial compression alone (ie, vs an Esmarch bandage or pneumatic vinyl splint for exsanguination) was sufficient in preventing maximum venous pressure (MVP), an indicator of leakage under the tourniquet. Nevertheless, using an Esmarch bandage, in that study, was associated with the most effective exsanguination of the limb, when compared with the use of vinyl splint or arm elevation/arterial compression alone.¹⁹

For patients with painful fractures of the upper arm, it may be completely appropriate to forego the Esmarch bandage, and instead, simply elevate the arm (while occluding the artery) for a minimum of 5 min to effect the requisite venous drainage of the extremity.

The usual dose of lidocaine (without epinephrine) administered is approximately 3 mg/kg, which is a relatively large dose in terms of systemic toxicity. Systemic toxic reactions can and do occur due to leakage past the tourniquet, sudden accidental deflation of the tourniquet during the procedure, or intentional deflation following brief surgical procedures.^{20, 21}

Block can be also accomplished using a smaller volume of more concentrated local anesthetic (eg, 12–15 mL of lidocaine 2%).

Lower Extremity IVRA

The only significant difference is that the IVRA technique for the lower extremity requires relatively larger volume of local anesthetic. This is necessary to more completely fill the larger vascular compartment of the lower extremity from the distally placed IV cannula to the proximal tourniquet (100 mL vs 50 mL) (see Figures 41–9 through 41–11).

Clinical Pearls

Lidocaine is the prototypical local anesthetic used for IVRA in the United States.