Relation of the successful block regional anesthesia with increased peripheral venous circumference and peripheral skin temperature at distal part of the block

Introduction: Evaluating the success rate of regional anesthesia is performed with pinprick test, Bromage score and pain scales, where they act as indicators of success or otherwise of motor, sensory and nociceptive blockade. The sympathetic system is also affected by the regional anesthesia blockade. The present study evaluated the relationship of peripheral venous dilatation and the skin temperature of the block area, to be used as an additional tool. Methodology: An analytic, observational study was conducted in Dr. Soetomo Surabaya Hospital. 18 patients received peripheral nerve block (PNB) and 16 patients received subarachnoid block (SAB). Informed consent was obtained from all the participants. The peripheral venous circumference was measured by using linear probe of Sonosite® M-Turbo ultrasound, before the blocks and then one hour after PNB and SAB to assess the venous dilatation. The peripheral skin temperature was measured with a thermometer (Microlife NC-150 Bluetooth®) infrared thermometer before the blocks, and within the range of 5 min from the zero min after the block until the 30th min. The success rate of the blocks was performed with pain scale (VAS) and absence of motor, sensory and nociceptive response Results: No relationship was found of sex, age, weight and type of block with increased peripheral venous circumference and peripheral skin temperature (p > 0.05). The block's success was associated with the increased peripheral venous circumference and peripheral skin temperature (p ≤ 0.001) in both PNB and SAB blocks. The average PNB block succeeded in 20 min while SAB took only 5 min (p < 0.05) to affect both of the parameters. The delta value of the increased temperature's successful block was 0.7°C in the PNB, and 0.275°C in the SAB group. Conclusions: The success of the peripheral nerve block and the subarachnoid block is associated with an increase in the peripheral venous circumference and in the peripheral skin temperature in the block area.