<p begin="00:00:13.460" end="00:00:14.935" style="s2">- The interscalene block is used</p>
<p begin="00:00:14.935" end="00:00:18.092" style="s2">for shoulder surgery and clavicle surgery.</p>
<p begin="00:00:18.092" end="00:00:19.843" style="s2">So, to start the interscalene block,</p>
<p begin="00:00:19.843" end="00:00:22.290" style="s2">proper positioning is very important.</p>
<p begin="00:00:22.290" end="00:00:25.260" style="s2">The best way to get to<br />the interscalene block</p>
<p begin="00:00:25.260" end="00:00:28.713" style="s2">is to have the patient sitting up</p>
<p begin="00:00:28.713" end="00:00:30.970" style="s2">about 30 or 45 degrees.</p>
<p begin="00:00:30.970" end="00:00:32.721" style="s2">Next, we turn the patients head away</p>
<p begin="00:00:32.721" end="00:00:35.731" style="s2">from the shoulder to the opposite side.</p>
<p begin="00:00:35.731" end="00:00:38.395" style="s2">This gives us a lot of<br />room to put the probe</p>
<p begin="00:00:38.395" end="00:00:42.012" style="s2">and have our hands come<br />from the posterior side.</p>
<p begin="00:00:42.012" end="00:00:44.829" style="s2">The proper approach to<br />the interscalene block</p>
<p begin="00:00:44.829" end="00:00:48.244" style="s2">is to have the needle approach<br />from the posterior side.</p>
<p begin="00:00:48.244" end="00:00:52.424" style="s2">This avoids the phrenic<br />nerve and allows us</p>
<p begin="00:00:52.424" end="00:00:56.019" style="s2">to not injure the phrenic<br />nerve with our needle approach.</p>
<p begin="00:00:56.019" end="00:00:57.452" style="s2">So, for the interscalene block,</p>
<p begin="00:00:57.452" end="00:01:01.022" style="s2">we usually use a high<br />frequency linear probe.</p>
<p begin="00:01:01.022" end="00:01:02.989" style="s2">The high frequency linear probe is best</p>
<p begin="00:01:02.989" end="00:01:05.550" style="s2">for structures that are superficial.</p>
<p begin="00:01:05.550" end="00:01:08.058" style="s2">Usually, in the interscalene groove,</p>
<p begin="00:01:08.058" end="00:01:10.303" style="s2">the interscalene nerves or the roots</p>
<p begin="00:01:10.303" end="00:01:13.271" style="s2">of the brachial plexus lie very shallow.</p>
<p begin="00:01:13.271" end="00:01:15.581" style="s2">Usually, two centimeters or less</p>
<p begin="00:01:15.581" end="00:01:17.684" style="s2">even in large patients.</p>
<p begin="00:01:17.684" end="00:01:20.607" style="s2">So, to start, I usually<br />set my ultrasound depth</p>
<p begin="00:01:20.607" end="00:01:22.642" style="s2">to approximately three centimeters</p>
<p begin="00:01:22.642" end="00:01:24.873" style="s2">in an average sized patient.</p>
<p begin="00:01:24.873" end="00:01:28.953" style="s2">I also set the frequency<br />to general setting</p>
<p begin="00:01:28.953" end="00:01:32.163" style="s2">or resolution setting,<br />in skinnier patients.</p>
<p begin="00:01:32.163" end="00:01:34.483" style="s2">To get to the interscalene groove</p>
<p begin="00:01:34.483" end="00:01:38.742" style="s2">the best place to start is in<br />the supraclavicular region.</p>
<p begin="00:01:38.742" end="00:01:41.557" style="s2">The reason we start in<br />the supraclavicular region</p>
<p begin="00:01:41.557" end="00:01:44.021" style="s2">is that it allows us to use</p>
<p begin="00:01:44.021" end="00:01:47.354" style="s2">a vascular structure to find the nerves.</p>
<p begin="00:01:49.333" end="00:01:51.564" style="s2">So, when I start, I put the probe on</p>
<p begin="00:01:51.564" end="00:01:53.312" style="s2">just posterior to the clavicle</p>
<p begin="00:01:53.312" end="00:01:55.812" style="s2">aiming straight down the body.</p>
<p begin="00:01:56.948" end="00:02:00.847" style="s2">In this area we will<br />see a pulsating artery</p>
<p begin="00:02:00.847" end="00:02:02.538" style="s2">sitting on the first rib,</p>
<p begin="00:02:02.538" end="00:02:05.288" style="s2">as well as some pleura, possibly.</p>
<p begin="00:02:06.139" end="00:02:09.506" style="s2">Posterior to the pulsating<br />subclavian artery</p>
<p begin="00:02:09.506" end="00:02:10.422" style="s2">are your nerves.</p>
<p begin="00:02:10.422" end="00:02:13.804" style="s2">Your nerves in this setting<br />are hyperechoic, or bright,</p>
<p begin="00:02:13.804" end="00:02:18.530" style="s2">and have many fascicles, or<br />dark circles, within 'em.</p>
<p begin="00:02:18.530" end="00:02:21.060" style="s2">These are the nerves that are gonna become</p>
<p begin="00:02:21.060" end="00:02:22.984" style="s2">the roots of the brachial plexus</p>
<p begin="00:02:22.984" end="00:02:25.615" style="s2">as we trace backwards up the neck.</p>
<p begin="00:02:25.615" end="00:02:28.367" style="s2">Now, to find the interscalene groove</p>
<p begin="00:02:28.367" end="00:02:30.283" style="s2">we take our pulsating artery,</p>
<p begin="00:02:30.283" end="00:02:32.066" style="s2">look for the nerves posterior,</p>
<p begin="00:02:32.066" end="00:02:35.037" style="s2">and we're gonna slide the<br />probe back up the neck.</p>
<p begin="00:02:35.037" end="00:02:37.820" style="s2">The probe slides up the<br />neck as well as tilts</p>
<p begin="00:02:37.820" end="00:02:39.900" style="s2">as we move the probe up the neck.</p>
<p begin="00:02:39.900" end="00:02:41.830" style="s2">Here, we are moving up the neck</p>
<p begin="00:02:41.830" end="00:02:45.690" style="s2">following the upper trunk,<br />this most superior nerve,</p>
<p begin="00:02:45.690" end="00:02:49.440" style="s2">as we go up the neck<br />those nerves will become</p>
<p begin="00:02:50.338" end="00:02:55.060" style="s2">more dark and larger<br />fascicles, or dark circles.</p>
<p begin="00:02:55.060" end="00:02:58.031" style="s2">Now, we are up at the interscalene groove.</p>
<p begin="00:02:58.031" end="00:03:01.368" style="s2">The interscalene groove<br />is found by identifying</p>
<p begin="00:03:01.368" end="00:03:02.935" style="s2">the anterior scalene muscle,</p>
<p begin="00:03:02.935" end="00:03:05.591" style="s2">anterior here is to the left of the screen</p>
<p begin="00:03:05.591" end="00:03:07.531" style="s2">and the middle scalene muscle</p>
<p begin="00:03:07.531" end="00:03:10.183" style="s2">posterior to the right of the screen.</p>
<p begin="00:03:10.183" end="00:03:13.603" style="s2">The nerves are hypoechoic,<br />or dark, surrounded by</p>
<p begin="00:03:13.603" end="00:03:17.020" style="s2">hyperechoic, or bright, fascial covering.</p>
<p begin="00:03:18.088" end="00:03:21.938" style="s2">Here, we are looking at<br />the C5 and C6 nerve roots</p>
<p begin="00:03:21.938" end="00:03:23.780" style="s2">in the interscalene groove.</p>
<p begin="00:03:23.780" end="00:03:25.470" style="s2">If I slide the probe anterior,</p>
<p begin="00:03:25.470" end="00:03:27.383" style="s2">we get a carotid artery</p>
<p begin="00:03:27.383" end="00:03:30.368" style="s2">with a internal jugular vein on top of it.</p>
<p begin="00:03:30.368" end="00:03:34.350" style="s2">The sternocleidomastoid<br />is above these structures.</p>
<p begin="00:03:34.350" end="00:03:38.094" style="s2">As I slide posterior, we<br />have out anterior scalene,</p>
<p begin="00:03:38.094" end="00:03:39.941" style="s2">our interscalene groove,</p>
<p begin="00:03:39.941" end="00:03:42.427" style="s2">and posterior is our middle scalene.</p>
<p begin="00:03:42.427" end="00:03:44.003" style="s2">Here is a very good picture</p>
<p begin="00:03:44.003" end="00:03:47.276" style="s2">of the nerve roots here and they are</p>
<p begin="00:03:47.276" end="00:03:50.560" style="s2">sandwiched between the<br />anterior scalene on the left</p>
<p begin="00:03:50.560" end="00:03:54.137" style="s2">and the middle scalene on the right.</p>
<p begin="00:03:54.137" end="00:03:56.007" style="s2">So, now, we are looking specifically</p>
<p begin="00:03:56.007" end="00:03:58.424" style="s2">at the C5 and C6 nerve roots.</p>
<p begin="00:04:00.034" end="00:04:02.877" style="s2">Our needle approach comes from posterior.</p>
<p begin="00:04:02.877" end="00:04:04.716" style="s2">Usually, I start the needle</p>
<p begin="00:04:04.716" end="00:04:07.939" style="s2">approximately one centimeter<br />away from the probe.</p>
<p begin="00:04:07.939" end="00:04:10.555" style="s2">In this image we see<br />the interscalene groove</p>
<p begin="00:04:10.555" end="00:04:12.888" style="s2">with the C5, C6 nerve roots.</p>
<p begin="00:04:14.372" end="00:04:17.978" style="s2">The needle is passing through<br />the middle scalene muscle.</p>
<p begin="00:04:17.978" end="00:04:20.975" style="s2">You'll see an injection<br />on the posterior side</p>
<p begin="00:04:20.975" end="00:04:22.892" style="s2">of the brachial plexus.</p>
<p begin="00:04:24.778" end="00:04:26.268" style="s2">The needle will be then moved</p>
<p begin="00:04:26.268" end="00:04:28.685" style="s2">underneath the C6 nerve root.</p>
<p begin="00:04:30.696" end="00:04:33.279" style="s2">An injection will be given now.</p>
<p begin="00:04:36.229" end="00:04:38.259" style="s2">You can see the local anesthetic spreading</p>
<p begin="00:04:38.259" end="00:04:41.089" style="s2">on the anterior side<br />of the brachial plexus,</p>
<p begin="00:04:41.089" end="00:04:44.933" style="s2">between the brachial plexus and<br />the anterior scalene muscle.</p>
<p begin="00:04:44.933" end="00:04:49.436" style="s2">And the needle is positioned<br />below the C6 nerve roots.</p>
<p begin="00:04:49.436" end="00:04:50.971" style="s2">I usually deposit about</p>
<p begin="00:04:50.971" end="00:04:54.133" style="s2">20 to 30 milliliters of local anesthetic.</p>
<p begin="00:04:54.133" end="00:04:57.042" style="s2">Some people use less to avoid</p>
<p begin="00:04:57.042" end="00:04:59.407" style="s2">paralysis of the phrenic<br />nerve, temporarily,</p>
<p begin="00:04:59.407" end="00:05:01.574" style="s2">from the local anesthetic.</p>