Bier block exsanguination: a volumetric comparison and venous pressure study.
OBJECTIVE
Intravenous regional anesthesia (IVRA) is a useful ED anesthetic technique. However, venous pressure elevation during injection can cause anesthetic leakage and toxicity. This is minimized by preinjection limb exsanguination. Although standard, Esmarch exsanguination is intolerable with limb trauma. Thus, the authors' objective was to study alternative methods.


METHODS
Volunteers had upper limb exsanguination performed by Esmarch bandage, arm elevation/arterial compression (AE/AC), and a pneumatic vinyl splint. Resultant volume changes, measured by volume displacement, were normalized, and expressed as percent decreases from baseline. Volume changes of all three methods were compared. The physiologic effectiveness of the AE/AC method was tested by measuring IV pressures during simulated IVRA. Attainment of maximum venous pressure (MVP) indicated leakage under the tourniquet.


RESULTS
All methods reduced limb volume compared with baseline (p < 0.05). No difference occurred between AE/AC and vinyl splint exsanguination (p > 0.99), but neither method was as effective as Esmarch (p < 0.05). Gender differences were noted in absolute volumes exsanguinated, but there was no difference in percent exsanguination. The AE/AC method was the simplest procedure to perform. Peak IV pressure during simulated IVRA after AE/AC was 85 mm Hg (males), and 199 mm Hg (females) (p < 0.05). The MVP was not reached.


CONCLUSIONS
While Esmarch was the most effective exsanguinating method, the two alternatives provided significant and equivalent decreases in limb volume. The AE/AC technique was physiologically effective in preventing attainment of MVP. Further studies are indicated to determine the clinical effectiveness of this technique in providing anesthesia for patients with limb trauma.
Mabee
J
J
Department of Emergency Medicine, Los Angeles County and University of Southern California Medical Center, 90033-1084, USA. mabee@hsc.usc.edu
Orlinsky
M
M
D000293:Adolescent; D000328:Adult; D000771:Anesthesia, Intravenous / Q000009:adverse effects / Q000379:methods*; D001132:Arm / Q000033:anatomy & histology / Q000098:blood supply / Q000502:physiology*; D001458:Bandages; D004630:Emergencies; D005260:Female; D006801:Humans; D008297:Male; D011187:Posture / Q000502:physiology; D013165:Splints; D014111:Tourniquets / Q000009:adverse effects; D014690:Venous Pressure