The technique of intravenous regional anesthesia (IVRA), or “Bier block,” was first introduced in 1908 by the German surgeon August Bier.1 A 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 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 components.2,3,4 after injecting the local anesthetic, 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 minutes, 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. Bier’s conclusion was that two mechanisms of anesthesia were associated with this technique: peripheral infiltration block and conduction block. The technique, as originally described by Bier, remains essentially unchanged in modern practice for the past 106 years, except for the introduction of the pneumatic-type double-tourniquet preparation used in current clinical practice5,6,7 (Figure 21–1).
Double pneumatic tourniquet system for use in intravenous regional anesthesia of the upper or lower extremity.
A Bier block can be used for brief surgical procedures or manipulations of the upper or lower extremity. However, the technique has 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 (CRPSs) (formerly known as reflex sympathetic dystrophy, with sympathetically maintained pain) as an alternative to repeated sympathetic ganglion 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 to 30 minutes 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 ...