LAUSR

Objectives Nerve blockade is a common procedure in peripheral limb surgery. In some cases however the anesthesia is directly followed by distally paresis and/or sensory disturbance. Method We describe the neurophysiological and ultasonographic findings of 5 cases in this patient group. Results 5 patients were examined clinically, neurophysiologically and with ultrasonography. All patients had permanent paresis and/-or sensory disturbance proximal to the site of surgery and distal to the site of peripheral nerve blockade. Neurophysiological findings showed markedly side-difference of motor – and sensory amplitudes suggesting axonal degeneration. Ultrasonography showed increased cross-sectional area/long-axis diameter of affected nerves and changes in intraneural and epineural structures at site of local anesthesia injection. Discussion Nerve injury following peripheral nerve blockade is a well-known complication, but the mechanisms are not well understood, specifically and ultrasonographic data are not yet available. Our series of patients showed axonal disturbance in several nerves distal to the site of peripheral nerve blockade. Ultrasonography showed morphological nerve changes at the side of anesthesia placement. Conclusions Peripheral nerve anesthesia may cause axonal motor and sensory nerve degeneration distally to anesthesia placement. Ultrasonographic changes in the nerve are mostly present at the site of anesthesia placement. Significance Peripheral nerve injury after nerve blockade has been described previously but the mechanisms are not understood - neurophysiological and ultrasonographic examinations are valuable and may contribute to an understanding of desease mechanisms. Our study may be of help in assessing the safety of local anesrhetics and potentially prevent persistent side-effects and nerve injury following the use of local anesthesia for limb surgery.