So I thought it was ok to have stimulation of the foot occurring down to approximately 0.4mA when injecting the local? You state if you get any stimulation at all, you shouldn’t inject the local as you might be intraneuronal. Please clarify. Great video!
Hi Glen. If you are using nerve stimulator to accomplish a nerve block, you have to dial down to get a motor response at 0.3-0.4 mA, otherwise you will not have a confirmation of the proper needle placement. What we know today - is - at the current of 0.3-0.4 mA you can be on the nerve or in the nerve without having a motor response in some 25% of cases. Therefore, if you are using ultrasound to monitor a) anatomy b) needle-nerve relationship and c) spread of the local anesthetic, we are using nerve stimulator as an additional monitor of b). If the needle on ultrasound is placed well b), and the distribution of the local anesthetic (c) is correct, we prefer NOT to have a motor response, and when it occurs, we re-focuss, pull the needle slightly back and confirm the adequate spread (c) by ultrasound. Best
Thanks for the reply Admir; I appreciate it! Your response makes sense and I will probably try to modify my technique a bit with your perspectives in mind. perhaps the old methodology of wanting a twitch is a bit outdated now. I do use both ultrasound and stimulation to help guide me with all my nerve blocks. Keep up the good work!
Hi Jason, You can find guidance and our protocols to all things regional anesthesia in NYSORA's COMPENDIUM of REGIONAL ANESTHESIA at nysoralms.com/courses/nysora-compendium-of-regional-anesthesia/ you will join thousands of your colleagues discussing management of anesthetic cases, always updated protocols and visual guidance to all procedures in regional anesthesia. Greetings from NYSORA
6.12 in video... biceps femoris is supposed to form lateral border of popliteal fossa and common peroneal nerve is also supposed to be lateral to tibial nerve. I think in this video - tibial nerve has been shown to lie on the same side as biceps femoris. Have i understood it wrong !!
Indeed. Thank you for pointing this out. Sometimes - a large screen gets you lost in orientation. Regardless, the principles described are still valid. Please feel free to comment/critique, etc as we are growing a community for teaching each other. Best regards
Had the same question. I believe it is the other way around. Simple mistake but definitely something that residents about to take the boards should be clear about as this anatomy will come up
so if you are doing a bimalleolar fracture do you have to do an adductor or femoral in addition to the POP block? What about if its just a poster pain block no tourniquet?
Yes. The saphenous nerve definitively innervates medial aspect of skin just below the medial malleolus and spahenous or femoral block are necessary for anesthesia. As a tip = you can do both - the femoral (short acting local anesthetic e.g. lidocaine 1-2%) and saphenous block (long acting LA - such as bupivacaine 0.25%). This would give you better anesthesia for the Tourniquet and long-acting analgesia in the saphenous nerve territory for the medial ankle. Admittedly, doing this case under pop-saphenou block requires substantial expertise.
Before U/S I commonly used nerve stimulation to locate the distal sciatic nerve. When doing this I usually started searching laterally in the triangle forms by the BF and ST tendons. I was a little surprised to see NYSORA starting more medially in the triangle, but the pictures do not lie.
Scott, thank you for the comment. And agreed - if you take popliteal fossa crease as a base, and the biceps femoris & semit/semimemb tendons as sides of the "triangle", the distal sciatic is closer to the lateral side of the triangle. In the video I point that out a couple of times, by stating that the ultrasound probe is best positioned between Biceps and Semim-Semitend tendons, closer to the biceps tendon. If you scroll to 13:35 into the video, the biceps muscle is seen/labeled above the biceps muscle - demonstrating that your point is re: off center laterally is correct. Greetings.
