Article Text
Abstract
Background and Aims Ultrasound guided peripheral nerve block for ankle surgery is appropriate alternative for spinal anaesthesia, allowing for earlier mobilization and adequate postoperative pain control.
Methods 38-year-old female, BMI 20.7, presented for hardware removal a year after an open reduction and internal fixation of bimalleolar ankle fracture. Ultrasound guided popliteal/saphenous nerve block was performed with spinal needle (G25, Quincke), using 0.5% levobupivacain and dexamethason as an adjuvant to local anaesthetic. Due to poor visualisation of saphenous nerve, paraesthesia was briefly elicited once during the procedure. Surgical procedure went uneventfully, in complete surgical block and intravenous sedation with propofol. Motor block persisted for 48 hours, with full recovery thereafter. Sensory deficit in the distribution area of saphenous nerve was present one month after the procedure.
Results The patient was highly satisfied with postoperative pain control with no need for additional analgesics, but concerned about peristing tingling sensation. She declined proposed multimodal treatment for neuropathic pain with calcium channel antagonist pregabalin, and agreed to therapy with NSAID and vitamin B supplements. Further evaluation of eventual prolonged neuropathy, including NMR and nerve conduction studies, was discussed with patient.
Conclusions Dexamethasone prolongs the effect of local anaesthetic when used as an adjuvant. In our case, the duration of motor and sensory block was longer than expected. Complications related to peripheral nerve blocks may go undiagnosed until the first postoperative control. Neural lesions related to peripheral nerve blocks usually resolve within 4 – 7 weeks and over 99% by one year.