Perfusion Index Value in Predicting the Clinical Outcome of Axillary Block

The interscalene brachial plexus block is an effective intervention for reducing postoperative pain but is related to side effects, Suprascapular nerve block and a block of the axillary nerve have been introduced as alternatives to the interscalene brachial plexus for the control of postoperative pain. Previous study demonstrated new method of axillary block using interfascial plane injection guided by ultrasoud. Axillary block has been used widely for the relief of postoperative arm pain.

Recent study deomonstrated good pain relief when ultrasound guided fascial plane injection was performed in patients with cervical radiuculopathy.

The perfusion index (PI) is a numerical value for the ratio between pulsatile and non-pulsatile blood flow measured by a special pulse oximeter. Although the special probe for PI measurement is relatively more expensive compared with ordinary pulse oximetery probes, its benefit as a marker of peripheral perfusion and as an idex for sympathetic stimulation have increased its use progressively. PI has been used widely for the prediction of success of brachial plexus block or axillary block. Changes of PI ratio value showed an excellent predictive value for the success of block.

There have been no studies demonstrating any predictive value of PI in axillary block for the relief of cervical radiulopathy