<prompt> A patient in ICU was on invasive monitoring with intra arterial canulation through right radial artery for last 3 days. Later he developed swelling and discolouration of right hand. The next line of management isStellate ganglion blockParavertebral blockRadial Nerve blockCeliac plexus block  <response>: Swelling and discoloration of hand after 3 days radial artery cannulation suggests arterial thrombosis.Radial artery cannulation can cause thrombosis of radial artery and ischemic damage. Aggressive management, e.g. brachial plexus block or stellate ganglion block may be required to avoid permanent damage. 