Prediction Of Successful Supraclavicular Brachial Plexus Block Using Pulse Oximeter Perfusion Index

ABSTRACT

Background and goalsSupraclavicular approach to brachial plexus block is a popular approach for anaesthesia for upper limb surgeries. Conventional methods for evaluation of block success are time consuming. The aim of this study is to evaluate whether the change in perfusion index (PI) can be used to predict the ultrasound-guided supraclavicular nerve block success.Methodology: The study was performed after written informed consent from 32 ASA PS I, II patients scheduled for elective hand, wrist and forearm surgery under ultrasound-guided supraclavicular nerve block. After local anaesthetic injection, sensory block success and motor block success was assessed every 5min.The PI was recorded at baseline and at 10, 20min after anaesthetic injection in both blocked and non-blocked limbs. The PI ratio was calculated as the PI after 20min divided by the PI at the baseline.Results:Baseline values of PI ranged from 0.2 to 3.42 in 32 patients for whom supraclavicular block was performed. At 10 min, percentage increase of PI was (mean ± standard deviation) 484.38 ± 295.80 % from baseline. At 20 min, percentage increase of PI was 557.31 ± 239.25 % from baseline. All changes from baseline were significant (p < 0.01) Conclusion: Perfusion index monitoring may provide a highly valuable tool to evaluate the success of regional anaesthesia of the upper extremity in clinical practice.