Abstract No.: ABS2191 : Comparative study between perfusion index and sensory function tests for determination of successful supraclavicular brachial plexus block

BACKGROUND & AIMS: Conventional tests are time consuming, subjective and require patient’s cooperation. The aim was to compare perfusion index with tactile stimulation in both blocked and unblocked arm to determine onset and more reliable indicator for PNS guided supraclavicular block success. METHODS: Comparative study conducted in MY hospital Indore over 1 month included 30 patients undergoing elective upper limb procedures under supraclavicular block. After local anaesthetic instillation, perfusion index (PI) readings by pulse oximeter and tactile stimulation by cold sensation in both arms were noted. They were graded as 2= normal,1= reduced, 0=absent. These were noted at baseline, 1,3,5,10 and 20 min. Graphs were constructed for comparison. RESULTS: PI was higher in blocked limb at all time points and tripled at 3 min while tactile stimulation showed a mean absent grade at 4 min 45 sec PI showed 100% sensitivity and specificity for block success at and after 3 mins when compared with tactile stimulation in both blocked and unblocked limbs. Comparison between both parameters was statistically significant (p value<0.001) at 3 min stating PI was faster and reliable indicator. CONCLUSION: Perfusion index is a faster and more accurate parameter of successful supraclavicular brachial plexus block than sensory function test. A tripling of PI around 3 min is a good predictor.