A patient selected for surgery induced with thiopental i.v. through one of the antecubital veins, complains of severe pain of whole hand. What should be the next line of management in this patient?

This patient developed pain after injection of thiopentone because it was administered intraaerially instead of intravenous route. When thiopentone is injected intraaerially, at body pH it gets precipitated into crystals and occlude small aerial blood vessels, provoke intense vasospasm and may lead to complete aerial thrombosis. After aerial injection patients usually complaints of pain distal to injection site, ischemic colour changes in the affected limb and later there can be even ulceration, edema and gangrene. Treatment options include: Leaving the cannula in place Injection of heparin to reduce risk of thrombosis Injection of warm NaCl to dilute the substance Injection of local anaesthetic and /or vasodilator: lidocaine, procaine, phenoxybenzamine Dexamethasone to reduce edema Sympathetic block: stellate ganglion or brachial plexus Ref: Concise Anatomy for Anaesthesia By Andreas G. Erdmann page 89., Fundamentals of Anaesthesia edited by Tim Smith, page 572.