An unusual complication of brachial plexus sheath cannulation

A 20-gauge cannula placed via an interscalene approach in the left brachial plexus sheath of a healthy 18-yr-old male was used inadvertently for injection of 20 ml of antibiotic solution, despite clear labelling of the cannula and painful protest from the patient. The patient suffered no neurological sequelae. The treatment, possible causes and steps to avoid similar incidents are described.