Respiratory failure after tracheal extubation secondary to phrenic nerve blockade and acute right hemidiaphragmatic paresis following supraclavicular brachial plexus anaesthesia

A man in his 70s with Parkinson's disease underwent urgent below-elbow amputation for gangrenous sepsis. A right supraclavicular brachial plexus catheter was placed for postoperative analgesia. Shortly after tracheal extubation, he developed acute hypercapnic respiratory failure due to ipsilateral hemidiaphragmatic paresis, requiring urgent tracheal re-intubation and a brief period of mechanical ventilation. Following cessation of the local anaesthetic infusion, diaphragmatic function returned and he was successfully re-extubated. A reduced-dose supraclavicular infusion was later reintroduced after multidisciplinary review, without recurrence. This case highlights an infrequent but clinically significant complication of supraclavicular block and emphasises diagnostic evaluation, risk stratification and safe reintroduction of regional analgesia.