<p begin="00:00:13.693" end="00:00:15.655" style="s2">- The Popliteal Sciatic Nerve Block</p>
<p begin="00:00:15.655" end="00:00:17.913" style="s2">is a good block to do<br />for the sciatic nerve</p>
<p begin="00:00:17.913" end="00:00:19.612" style="s2">because this is where the sciatic nerve</p>
<p begin="00:00:19.612" end="00:00:21.445" style="s2">is found most shallow.</p>
<p begin="00:00:22.294" end="00:00:25.719" style="s2">This block can be performed<br />for post year knee pain</p>
<p begin="00:00:25.719" end="00:00:29.196" style="s2">after knee surgery, as well as, calf, foot</p>
<p begin="00:00:29.196" end="00:00:31.331" style="s2">and ankle surgery.</p>
<p begin="00:00:31.331" end="00:00:34.608" style="s2">This is the main nerve that<br />supplies the lower leg.</p>
<p begin="00:00:34.608" end="00:00:37.477" style="s2">I find a lateral position<br />gives you good control</p>
<p begin="00:00:37.477" end="00:00:40.446" style="s2">of the patients airways if you sedate them</p>
<p begin="00:00:40.446" end="00:00:44.279" style="s2">as well as good ergo-dynamics<br />to do the block.</p>
<p begin="00:00:45.484" end="00:00:48.476" style="s2">Here we have our patient<br />positioned laterally</p>
<p begin="00:00:48.476" end="00:00:51.384" style="s2">with a pillow between<br />the legs for comfort.</p>
<p begin="00:00:51.384" end="00:00:54.053" style="s2">To do the Popliteal Sciatic Nerve Block</p>
<p begin="00:00:54.053" end="00:00:55.771" style="s2">we use a linear probe.</p>
<p begin="00:00:55.771" end="00:00:59.348" style="s2">The linear probe allows<br />us to see structures well</p>
<p begin="00:00:59.348" end="00:01:00.939" style="s2">in the shallow plane,</p>
<p begin="00:01:00.939" end="00:01:02.574" style="s2">but gives us a wide field of view</p>
<p begin="00:01:02.574" end="00:01:04.722" style="s2">to see our needle approaching the nerve.</p>
<p begin="00:01:04.722" end="00:01:07.025" style="s2">To perform the Politeal<br />Sciatic Nerve Block</p>
<p begin="00:01:07.025" end="00:01:11.174" style="s2">we put the probe directly<br />in the back of the knee.</p>
<p begin="00:01:11.174" end="00:01:13.318" style="s2">Placement of the probe<br />in the back of the knee</p>
<p begin="00:01:13.318" end="00:01:17.485" style="s2">reveals a structure of the<br />nerve, the vein, the artery.</p>
<p begin="00:01:19.042" end="00:01:22.694" style="s2">I call this structure, the<br />snowman in the back of the knee.</p>
<p begin="00:01:22.694" end="00:01:25.132" style="s2">You have three circles<br />on top of each other.</p>
<p begin="00:01:25.132" end="00:01:27.743" style="s2">The upper most circle<br />represented by the tibial</p>
<p begin="00:01:27.743" end="00:01:29.548" style="s2">component of the sciatic nerve.</p>
<p begin="00:01:29.548" end="00:01:32.631" style="s2">The middle structure<br />represented by the vein</p>
<p begin="00:01:32.631" end="00:01:36.474" style="s2">and the deep structure represented<br />by the popliteal artery.</p>
<p begin="00:01:36.474" end="00:01:40.168" style="s2">If we put color Doppler on the screen</p>
<p begin="00:01:40.168" end="00:01:43.298" style="s2">we are able to see the pulsating artery</p>
<p begin="00:01:43.298" end="00:01:44.381" style="s2">in this area.</p>
<p begin="00:01:45.988" end="00:01:48.813" style="s2">Sometimes it's difficult<br />to see the popliteal vein</p>
<p begin="00:01:48.813" end="00:01:50.659" style="s2">because this is a low-flow state,</p>
<p begin="00:01:50.659" end="00:01:52.764" style="s2">such as we see here.</p>
<p begin="00:01:52.764" end="00:01:55.823" style="s2">To visualize the popliteal vein better</p>
<p begin="00:01:55.823" end="00:01:58.012" style="s2">we can squeeze the back of the calf,</p>
<p begin="00:01:58.012" end="00:02:00.638" style="s2">increasing venous flow<br />through the popliteal vein,</p>
<p begin="00:02:00.638" end="00:02:01.721" style="s2">such as this.</p>
<p begin="00:02:04.049" end="00:02:06.270" style="s2">There we can see increased venous flow</p>
<p begin="00:02:06.270" end="00:02:08.800" style="s2">through the popliteal<br />vein represented better</p>
<p begin="00:02:08.800" end="00:02:10.217" style="s2">by color Doppler.</p>
<p begin="00:02:11.812" end="00:02:14.746" style="s2">Now, as I mentioned, this<br />is only the tibial component</p>
<p begin="00:02:14.746" end="00:02:16.367" style="s2">of the sciatic nerve.</p>
<p begin="00:02:16.367" end="00:02:19.003" style="s2">We wanna get the nerve<br />where it comes together</p>
<p begin="00:02:19.003" end="00:02:22.440" style="s2">and has both components, the peroneal</p>
<p begin="00:02:22.440" end="00:02:25.310" style="s2">and the tibial component.</p>
<p begin="00:02:25.310" end="00:02:28.063" style="s2">As we scan up the leg, here we now see</p>
<p begin="00:02:28.063" end="00:02:30.683" style="s2">the peroneal component laterally,</p>
<p begin="00:02:30.683" end="00:02:32.936" style="s2">the tibial component medially,</p>
<p begin="00:02:32.936" end="00:02:36.269" style="s2">the popliteal vein and popliteal artery.</p>
<p begin="00:02:38.709" end="00:02:42.317" style="s2">On the medial side we<br />see the semitendinosus</p>
<p begin="00:02:42.317" end="00:02:44.344" style="s2">and semimembranosus muscles.</p>
<p begin="00:02:44.344" end="00:02:46.449" style="s2">On the lateral side we see</p>
<p begin="00:02:46.449" end="00:02:50.354" style="s2">the biceps femoris, long and short heads.</p>
<p begin="00:02:50.354" end="00:02:52.827" style="s2">As we keep going up the leg</p>
<p begin="00:02:52.827" end="00:02:56.994" style="s2">the tibial and peroneal<br />components join into one nerve.</p>
<p begin="00:02:58.244" end="00:03:00.768" style="s2">Sometimes we block the nerve at this level</p>
<p begin="00:03:00.768" end="00:03:02.772" style="s2">where the two components are joining.</p>
<p begin="00:03:02.772" end="00:03:05.911" style="s2">This allows us to get both components</p>
<p begin="00:03:05.911" end="00:03:09.053" style="s2">with a single injection at the nerve.</p>
<p begin="00:03:09.053" end="00:03:10.843" style="s2">My needle approach for these blocks</p>
<p begin="00:03:10.843" end="00:03:13.643" style="s2">are gonna be from lateral to medial.</p>
<p begin="00:03:13.643" end="00:03:15.521" style="s2">What I typically do is measure the depth</p>
<p begin="00:03:15.521" end="00:03:18.554" style="s2">of the sciatic nerve in this setting.</p>
<p begin="00:03:18.554" end="00:03:20.381" style="s2">Here the sciatic nerve is approximately</p>
<p begin="00:03:20.381" end="00:03:24.589" style="s2">one-and-a-half to two<br />centimeters deep to the probe.</p>
<p begin="00:03:24.589" end="00:03:28.082" style="s2">So if I measure one-and-a-half<br />to two centimeters deep,</p>
<p begin="00:03:28.082" end="00:03:30.799" style="s2">my needle is gonna come in<br />completely perpendicular</p>
<p begin="00:03:30.799" end="00:03:33.959" style="s2">and have a very bright view of the needle</p>
<p begin="00:03:33.959" end="00:03:36.856" style="s2">and needle shaft as it<br />advances to the nerve.</p>
<p begin="00:03:36.856" end="00:03:40.176" style="s2">Now, I typically like to<br />inject deep to the nerve</p>
<p begin="00:03:40.176" end="00:03:42.240" style="s2">as well as superficial to the nerve</p>
<p begin="00:03:42.240" end="00:03:44.732" style="s2">in order to get complete surrounding</p>
<p begin="00:03:44.732" end="00:03:46.534" style="s2">of the popliteal sciatic nerve</p>
<p begin="00:03:46.534" end="00:03:50.139" style="s2">for the most rapid onset for this block.</p>
<p begin="00:03:50.139" end="00:03:53.233" style="s2">Typical volumes used<br />are 20 to 30 milliliters</p>
<p begin="00:03:53.233" end="00:03:55.447" style="s2">of local anesthetic.</p>
<p begin="00:03:55.447" end="00:03:57.769" style="s2">This block takes some time to onset</p>
<p begin="00:03:57.769" end="00:04:00.922" style="s2">and studies have shown even<br />with complete surrounding</p>
<p begin="00:04:00.922" end="00:04:02.997" style="s2">of the nerve, it takes up to 30 minutes</p>
<p begin="00:04:02.997" end="00:04:06.830" style="s2">for the nerve block to<br />onset in most patients.</p>
<p begin="00:04:09.719" end="00:04:12.479" style="s2">Here we see the popliteal sciatic nerve</p>
<p begin="00:04:12.479" end="00:04:16.705" style="s2">surrounded by the biceps femoris laterally</p>
<p begin="00:04:16.705" end="00:04:20.165" style="s2">and the semitendinosis/semimembranosis<br />medially.</p>
<p begin="00:04:20.165" end="00:04:22.886" style="s2">Our needle is advanced<br />directly above the nerve</p>
<p begin="00:04:22.886" end="00:04:24.845" style="s2">and the local anesthetic is injected,</p>
<p begin="00:04:24.845" end="00:04:27.727" style="s2">pushing the nerve deeper.</p>
<p begin="00:04:27.727" end="00:04:29.571" style="s2">We then withdraw the needle</p>
<p begin="00:04:29.571" end="00:04:33.654" style="s2">and readvance the needle<br />again close to the nerve</p>
<p begin="00:04:38.129" end="00:04:40.788" style="s2">so we can get local anesthetic spreading</p>
<p begin="00:04:40.788" end="00:04:42.769" style="s2">to the medial side of the nerve,</p>
<p begin="00:04:42.769" end="00:04:45.936" style="s2">which is more of the tibial component.</p>
<p begin="00:04:51.609" end="00:04:56.299" style="s2">Now you can visualize both the<br />peroneal and tibial component</p>
<p begin="00:04:56.299" end="00:05:00.466" style="s2">with a local anesthetic<br />completely surrounding the nerves.</p>
