DETECTION OF INTRANEURAL NEEDLE PLACEMENT WITH MULTIPLE FREQUENCY BIO-IMPEDANCE
Dr. Axel R. Sauter 1,2
1 Department of Research and Development Oslo University Hospital. Oslo. Norway
2 Department of Anesthesiology and Pain Medicine lnselspital, Bern University Hospital. Bern, Switzerland
Nerve injuries related to peripheral nerve blocks can be caused by toxicity of the injectied solution or by mechanical nerve damage. In the worst cases, nerve damage can lead to persistent motor or sensory impairment and debilitating neuropathic pain 1, 2. Thus, it is highly important to avoid such iatrogenic injuries. Penetration of a nerve alone does not necessarily lead to lasting damage unless local anesthetic is injected within the nerve fascicle 3.Hence, if intraneural needle placement is identified in time, the needle could be withdrawn and nerve injury can be avoided. Ultrasound guidance 4, electrical nerve stimulation 5- 7, and injection pressure measurements 8, 9 are used to reduce the risk of intraneural needle placement and injection.