Supraclavicular brachial plexus block provides dense anaesthesia to the upper arm, elbow and

forearm. The superficial placement of the plexus at this site leads to good sonographic

visualisation and a quick procedure that is well tolerated by patients in operating room. The

improved safety afforded by the use of ultrasound allowing the visualisation of pleura has

likely being the turning point in the increased use of supraclavicular blockade as a mode of

anaesthesia for upper limb surgeries and hence it is routinely performed.

There are numerous methods for assessment of brachial block success. One of the methods

for assessment of peripheral nerve blocks is by assessing the sensory and motor function

using pin prick for sensory blockade and motor function assessment for motor blockade

which are subjective, time consuming and needs a lot of patients cooperation. Others are

objective methods like changes in skin temperature, vasodilation and changes in blood flow.

The perfusion index is the ratio of the pulsatile blood flow to the non pulsatile or

static blood in peripheral tissue. Perfusion index thus represents a non invasive measure of

peripheral perfusion that can be continuously and non invasively obtained from pulse

oximeter