Evaluation of the accuracy of vibration sense with VibraTip™ as a tool to determine the level of anesthesia following subarachnoid block and its correlation with the pinprick sensation

BACKGROUND AND AIMS: Assessment of level of anesthesia after subarachnoid block (SAB) is essential. We aimed to evaluate the efficacy of vibration sense as a criteria to determine the level of surgical anesthesia. METHOD AND MATERIALS: The study included patients, scheduled for various surgeries under SAB. The baseline values of vibration sense perception using VibraTip™, motor power using the modified Bromage scale, and sensory block by pinprick method were recorded preoperatively and at 5 and 7 min after administration of SAB. The correlation between vibration sense, loss of pinprick sensation, and level of anesthesia were assessed. RESULTS: The concordance correlation coefficient between the pinprick and vibration sense at 5 min and 7 min showed poor strength of agreement with Pearson ρ (precision) being 0.4192 at 5 min and 0.4701 at 7 min. CONCLUSION: Vibration sense serves as a reliable indicator to assess the level of surgical anesthesia following SAB. Vibration sense testing with VibraTip™along with motor power assessment can be used as a tool for assessment of level of block. There is a poor correlation between level of vibration sense and pinprick.