A patient in the ICU was on invasive monitoring with intraarterial cannulation through

A patient in the ICU was on invasive monitoring with intraarterial cannulation through the right radial artery for the last 3 days. Later, he developed swelling and discoloration of the right hand. The next line of management is


a) stellate ganglion block 
b) brachial block  
c) radial nerve block on the same side  
d) application of lignocaine jelly over the site


Ans (a)