1. Ischaemic Arm Block Dr Peter Jones Emergency Medicine Specialist Auckland City Hospital

2. IVRAIntraVenous Regional Anaesthesia • >160 IVRA procedures / yr in Auckland ED • Bier 1908 • Advantages • Simple • Safe • No fatalities recorded in literature • Effective anaesthesia • Bloodless field • Muscle relaxation

3. Indications Any limb procedure Cooperative patient Contraindications Absolute Hypertension Allergy to amide LA Relative Uncooperative patient Not fasted Intoxicated Obtunded IVRA

4. IVRA Equipment • Resuscitation • Monitoring • Pneumatic tourniquet • Prilocaine • POP stuff • Documentation – procedures sheet • Staffing • Proceduralist • Medicator / Monitoring • Plasterer

5. IVRA Technique • Label in procedures book • Let radiology know • Consent • Weigh • Record • Why they fell! • Past anaesthetic / Medical / Allergy history • Current CVS status / fasting state • Limb neurovascular status

6. IVRA Technique • Monitoring • Continuous ECG, SPO2, RR, BP • BP Initially • Same arm / Same cuff • 2 IVs • 18g other arm – resus IV • 22g injured arm – lightly taped • Better anaesthesia if more distally placed • Exanguinate • 1-3min

7. IVRA Technique • Double cuff • Inflate proximal first • Infuse Prilocaine • Inflate distal cuff • Take out 22g line, apply pressure • Wait 5-10 minutes (anaesthesia achieved) • Perform procedure

8. IVRAPrilocaine 0.5% plain 3mg/kg = 0.6mL / kgMax 200mg = 40mL • Kinetics • Onset minutes • 10 min to max sensory block • Protein bound 55% • Tissue Binding • Metabolised • amidases – liver/lung/kidney • Post tourniquet • Plasma concentration 4-5mcg/ml • Sensation recovers <10min • T ½ α=3min, β=30min

9. IVRAPrilocaine 0.5% plain 3mg/kg = 0.6mL / kgMax 200mg = 40mL • Caution • Heart block • Anti-arrythmics • Methaemoglobinaemia • O-toluidine metabolite • <400mg not reported (adults) • Increased risk infants

10. IVRA Technique(wrist / forearm #) • Reduce # • 1st layer of POP • Repeat xRay • At bedside, cuff still up • Remanipulate if required • Complete POP

11. IVRA Technique (wrist / forearm #) • Tourniquet off • 20 minute minimum • 90 minute maximum • Deflation / Inflation (reduces peak plasma levels) ?not required • Recheck Neurovascular status • Post procedure instructions / follow up • Complete documentation

12. IVRA • Common problems • Cant tolerate cuff • Deflate proximal cuff (buys time) • Systemic analgesia • Entonox • Reassurance • Complications <2% • Transient tinnitus, dizziness, bradycardia

13. Complications The danger of thin skin

14. Complications Not checking the pulse (her BP was >200mmHg)

15. Summary • Performed correctly, upper limb IVRA is a safe and effective procedure

16. Questions? How are we doing this run??

17. References • Brown EM et al. IVRA (Bier Block): review of 20 years’ experience • Can J Anaesth. 1989 36(3 pt 1):307-10 • Roberts and Hedges: Clinical Procedures in Emergency Medicine 3rd Ed. 1998 (pp 511-515) • Pitkanen MT et al. Comparison of 0.5% articaine and 0.5% prilocaine in IVRA of the arm: a crossover study in volunteers • Reg. Anesth. Pain Med. 1999 (2) 131-5 • Simon MA et al. Comparison of the disposition kinetics of lidocaine and prilocaine in 20 patients undergoing IVRA during day stay surgery • J Clin Pharm Ther. 1997 (2) 141-6 • Simon MA et al IVRA with 0.5% articaine, 0.5% lidocaine, or 0.5% prilocaine. A double blind crossover study • Reg. Anesth. 1997 (1) 29-34