A New Inguinal Approach for the Obturator Nerve Block

Ultrasound-Guided Obturator Nerve Block

“…Currently, there are limited data comparing US-guided and nerve stimulation techniques to perform ONB. Studies based on conventional approaches described by Labat, 7 Wassef, 8 and Choquet et al 9 have examined the quality of ONB where nerve stimulation was the end point for LA injection and have reported success rates between 60% and 100%. Several limitations may explain some of the failures encountered: difficulty in correct needle placement because of imprecise surface landmarks, anatomic variability, and inadequate LA diffusion despite an apparently correct electrical end point.…”

Ultrasound-Guided Obturator Nerve Block

“…1,2 Common approaches to block the obturator nerve (ON) use surface landmarks with or without nerve stimulation to localize this nerve. 3,4 In these studies, any weakness of thigh adduction was considered evidence of successful ONB, with a range of 60% (SD, 18%) to 77% (SD, 17%) reduction of adductor strength reported within 30 mins. 3,5 Recently, the ultrasonographic appearance of the ON in volunteers has been described, and ONB using ultrasound guidance (USG) in combination with nerve stimulation was also mentioned.…”

“…3,4 In these studies, any weakness of thigh adduction was considered evidence of successful ONB, with a range of 60% (SD, 18%) to 77% (SD, 17%) reduction of adductor strength reported within 30 mins. 3,5 Recently, the ultrasonographic appearance of the ON in volunteers has been described, and ONB using ultrasound guidance (USG) in combination with nerve stimulation was also mentioned. 6 In this report, we describe ONB with USG, but without the addition of nerve stimulation for block performance.…”

Is There Any Need for Expanding the Perineural Space Before Catheter Placement in Continuous Femoral Nerve Blocks?

“…1,2 They guarantee good femoral block quality, which, combined with effective obturator and sciatic nerve blocks, provides a surgical quality of analgesia. 6,7 Failed electrolocation via the stimulating catheters obviously resulted in lateral images and in failed blocks. The atypical images with distal spread of contrast surprisingly have not been identified and reported in previous studies.…”

“…7,8 The following unique protocol was applied: after raising a skin wheal with 2 mL lidocaine 1%, the skin was preincised with the 18-gauge needle, and the introducer needle assembly was then inserted and directed toward the femoral nerve with the neurostimulator initially set at 1.5 mA (1-2 Hz, 0.1 millisecond) in search of typical quadriceps contraction (patella dancing). Vastus medialis quadriceps contraction was accepted only in case of difficulty.…”