<p begin="00:00:13.632" end="00:00:17.077" style="s2">- Axillary nerve blocks<br />are used for surgery,</p>
<p begin="00:00:17.077" end="00:00:19.123" style="s2">usually below the elbow.</p>
<p begin="00:00:19.123" end="00:00:21.487" style="s2">If properly executed, axillary nerve block</p>
<p begin="00:00:21.487" end="00:00:24.326" style="s2">can be performed by<br />identifying individual nerves</p>
<p begin="00:00:24.326" end="00:00:26.740" style="s2">or just in depositing local anesthetic</p>
<p begin="00:00:26.740" end="00:00:30.393" style="s2">below the artery and<br />above the axillary artery.</p>
<p begin="00:00:30.393" end="00:00:32.991" style="s2">Axillary nerve blocks under ultrasound</p>
<p begin="00:00:32.991" end="00:00:35.375" style="s2">can improve safety because you can view</p>
<p begin="00:00:35.375" end="00:00:39.223" style="s2">many of the small arteries<br />and veins in the axilla,</p>
<p begin="00:00:39.223" end="00:00:42.056" style="s2">and avoid intravascular injection.</p>
<p begin="00:00:43.035" end="00:00:46.036" style="s2">To properly position for<br />the axillary nerve block,</p>
<p begin="00:00:46.036" end="00:00:49.332" style="s2">we have moved our patient to<br />the opposite side of the bed,</p>
<p begin="00:00:49.332" end="00:00:52.994" style="s2">and we will now abduct the arm 90 degrees.</p>
<p begin="00:00:52.994" end="00:00:54.594" style="s2">For the axillary nerve block,</p>
<p begin="00:00:54.594" end="00:00:56.826" style="s2">we usually use a linear probe.</p>
<p begin="00:00:56.826" end="00:00:59.911" style="s2">Usually axillary nerve<br />blocks are very shallow,</p>
<p begin="00:00:59.911" end="00:01:02.733" style="s2">so I've put my initial depth setting</p>
<p begin="00:01:02.733" end="00:01:05.900" style="s2">to about two and a half<br />to three centimeters.</p>
<p begin="00:01:05.900" end="00:01:09.949" style="s2">Usually, I also set the frequency settings</p>
<p begin="00:01:09.949" end="00:01:14.572" style="s2">to general or resolution for<br />the axillary nerve block.</p>
<p begin="00:01:14.572" end="00:01:18.489" style="s2">To do a properly executed<br />axillary nerve block,</p>
<p begin="00:01:19.912" end="00:01:23.424" style="s2">identification of the artery<br />and vein is important.</p>
<p begin="00:01:23.424" end="00:01:25.378" style="s2">If you find the artery,</p>
<p begin="00:01:25.378" end="00:01:29.048" style="s2">injection below and<br />above the axillary artery</p>
<p begin="00:01:29.048" end="00:01:32.613" style="s2">usually results in a good nerve block.</p>
<p begin="00:01:32.613" end="00:01:36.127" style="s2">We initially place the<br />probe in the axilla,</p>
<p begin="00:01:36.127" end="00:01:39.670" style="s2">and identify a pulsating<br />artery in the axilla.</p>
<p begin="00:01:39.670" end="00:01:42.087" style="s2">This is your axillary artery.</p>
<p begin="00:01:42.940" end="00:01:46.593" style="s2">Now, as you can see, the pulsating artery,</p>
<p begin="00:01:46.593" end="00:01:49.040" style="s2">there is no vein in my initial picture.</p>
<p begin="00:01:49.040" end="00:01:51.630" style="s2">This is because the vein is collapsed</p>
<p begin="00:01:51.630" end="00:01:53.572" style="s2">with light pressure of the probe.</p>
<p begin="00:01:53.572" end="00:01:56.632" style="s2">It is very important to<br />identify the axillary vein,</p>
<p begin="00:01:56.632" end="00:01:59.914" style="s2">so you do not inject<br />into the axillary vein.</p>
<p begin="00:01:59.914" end="00:02:01.419" style="s2">As I let up some pressure,</p>
<p begin="00:02:01.419" end="00:02:03.718" style="s2">you can now see the axillary vein</p>
<p begin="00:02:03.718" end="00:02:06.635" style="s2">superficial to my pulsating artery.</p>
<p begin="00:02:07.485" end="00:02:10.818" style="s2">Other structures visualized in this shot</p>
<p begin="00:02:11.714" end="00:02:14.892" style="s2">include the biceps and coracobrachialis</p>
<p begin="00:02:14.892" end="00:02:17.217" style="s2">on the right side of the screen,</p>
<p begin="00:02:17.217" end="00:02:20.040" style="s2">and either the latissimus dorsi,</p>
<p begin="00:02:20.040" end="00:02:23.288" style="s2">or the triceps, on the<br />left side of the screen,</p>
<p begin="00:02:23.288" end="00:02:26.560" style="s2">depending on what level I am at.</p>
<p begin="00:02:26.560" end="00:02:29.474" style="s2">Our needle approach to the axillary block</p>
<p begin="00:02:29.474" end="00:02:33.068" style="s2">is always cranial to<br />caudal in this direction.</p>
<p begin="00:02:33.068" end="00:02:35.184" style="s2">The reason we come cranial to caudal</p>
<p begin="00:02:35.184" end="00:02:36.519" style="s2">is for two reasons:</p>
<p begin="00:02:36.519" end="00:02:39.339" style="s2">the axillary vein, as<br />you see on the picture,</p>
<p begin="00:02:39.339" end="00:02:40.714" style="s2">usually lies caudal,</p>
<p begin="00:02:40.714" end="00:02:43.176" style="s2">and we do not wanna<br />puncture the axillary vein</p>
<p begin="00:02:43.176" end="00:02:46.425" style="s2">with a needle approach<br />from the caudal side.</p>
<p begin="00:02:46.425" end="00:02:50.089" style="s2">Also, it's much cleaner<br />to go through the deltoid</p>
<p begin="00:02:50.089" end="00:02:53.256" style="s2">or the biceps, rather than the axilla.</p>
<p begin="00:02:54.454" end="00:02:57.204" style="s2">My initial needle insertion point</p>
<p begin="00:02:58.069" end="00:03:01.401" style="s2">will direct the needle below the artery.</p>
<p begin="00:03:01.401" end="00:03:03.322" style="s2">If you inject below the artery,</p>
<p begin="00:03:03.322" end="00:03:05.838" style="s2">local anesthetic can spread backwards</p>
<p begin="00:03:05.838" end="00:03:08.996" style="s2">along the latissimus<br />dorsi, or triceps muscle,</p>
<p begin="00:03:08.996" end="00:03:12.349" style="s2">to get to the radial and ulnar nerves.</p>
<p begin="00:03:12.349" end="00:03:13.908" style="s2">Here, we can see the needle,</p>
<p begin="00:03:13.908" end="00:03:17.175" style="s2">advancing through the biceps muscle.</p>
<p begin="00:03:17.175" end="00:03:20.519" style="s2">Our first injection is<br />gonna be below the artery,</p>
<p begin="00:03:20.519" end="00:03:23.712" style="s2">and you can see the needle<br />advancing to that area.</p>
<p begin="00:03:23.712" end="00:03:28.164" style="s2">You can see the axillary<br />artery, and the axillary vein.</p>
<p begin="00:03:28.164" end="00:03:32.376" style="s2">The radial nerve is located<br />deep to the axillary artery.</p>
<p begin="00:03:32.376" end="00:03:36.500" style="s2">The ulnar nerve is located<br />between the artery and vein,</p>
<p begin="00:03:36.500" end="00:03:41.022" style="s2">and the median nerve is<br />located at nine o'clock</p>
<p begin="00:03:41.022" end="00:03:42.962" style="s2">on the axillary artery.</p>
<p begin="00:03:42.962" end="00:03:46.867" style="s2">Now we see the needle being<br />advanced above the artery.</p>
<p begin="00:03:46.867" end="00:03:50.416" style="s2">You can see the local anesthetic<br />has already been injected</p>
<p begin="00:03:50.416" end="00:03:51.761" style="s2">deep to the artery,</p>
<p begin="00:03:51.761" end="00:03:55.085" style="s2">and now the median nerve is<br />sitting on top of the artery,</p>
<p begin="00:03:55.085" end="00:03:56.879" style="s2">at twelve o'clock.</p>
<p begin="00:03:56.879" end="00:03:59.426" style="s2">The needle is now pushing the artery down</p>
<p begin="00:03:59.426" end="00:04:02.861" style="s2">and injecting local anesthetic<br />all around the artery</p>
<p begin="00:04:02.861" end="00:04:04.611" style="s2">and the median nerve.</p>
<p begin="00:04:08.096" end="00:04:11.580" style="s2">We then advance the needle<br />towards the ulnar nerve,</p>
<p begin="00:04:11.580" end="00:04:15.330" style="s2">which is now directly<br />in front of the needle.</p>
<p begin="00:04:16.246" end="00:04:18.139" style="s2">Our goal is to get local anesthetic</p>
<p begin="00:04:18.139" end="00:04:20.472" style="s2">around the ulnar nerve here.</p>
<p begin="00:04:22.140" end="00:04:26.054" style="s2">Total volume injected appears to be large,</p>
<p begin="00:04:26.054" end="00:04:29.137" style="s2">but it is only 20 milliliters so far.</p>
<p begin="00:04:33.597" end="00:04:35.309" style="s2">Now the ulnar nerve is visible,</p>
<p begin="00:04:35.309" end="00:04:37.273" style="s2">floating in the local anesthetic,</p>
<p begin="00:04:37.273" end="00:04:39.640" style="s2">in the median on top of the artery.</p>
<p begin="00:04:39.640" end="00:04:44.395" style="s2">Next, I would like to identify<br />the musculocutaneous nerve.</p>
<p begin="00:04:44.395" end="00:04:47.514" style="s2">The musculocutaneous<br />nerve is the fourth nerve</p>
<p begin="00:04:47.514" end="00:04:50.842" style="s2">of a properly executed axillary block.</p>
<p begin="00:04:50.842" end="00:04:55.123" style="s2">I find the musculocutaneous<br />nerve by moving slightly distal</p>
<p begin="00:04:55.123" end="00:04:56.290" style="s2">along the arm.</p>
<p begin="00:04:57.741" end="00:05:00.044" style="s2">I also wanna increase the depth,</p>
<p begin="00:05:00.044" end="00:05:02.439" style="s2">and look for a hyperechoic nerve</p>
<p begin="00:05:02.439" end="00:05:06.338" style="s2">within the biceps or<br />coracobrachialis muscle.</p>
<p begin="00:05:06.338" end="00:05:09.103" style="s2">Traditionally, the musculocutaneous nerve</p>
<p begin="00:05:09.103" end="00:05:11.270" style="s2">can be oval or triangular.</p>
<p begin="00:05:12.182" end="00:05:15.121" style="s2">The musculocutaneous nerve<br />is one of the brightest,</p>
<p begin="00:05:15.121" end="00:05:17.810" style="s2">or most hyperechoic nerves in the body,</p>
<p begin="00:05:17.810" end="00:05:20.342" style="s2">and it's easily blocked<br />with local anesthetic</p>
<p begin="00:05:20.342" end="00:05:23.811" style="s2">in the realm of three to five milliliters.</p>
<p begin="00:05:23.811" end="00:05:28.121" style="s2">Here we see a hyperechoic<br />musculocutaneous nerve</p>
<p begin="00:05:28.121" end="00:05:30.849" style="s2">surrounded by a hyperechoic fascia.</p>
<p begin="00:05:30.849" end="00:05:33.948" style="s2">Our needle is being advanced<br />to the lateral portion.</p>
<p begin="00:05:33.948" end="00:05:36.956" style="s2">The local anesthetic is now being injected</p>
<p begin="00:05:36.956" end="00:05:39.705" style="s2">below the musculocutaneous nerve,</p>
<p begin="00:05:39.705" end="00:05:42.201" style="s2">and now above the musculocutaneous nerve,</p>
<p begin="00:05:42.201" end="00:05:44.998" style="s2">to give complete<br />surrounding of that nerve.</p>
<p begin="00:05:44.998" end="00:05:48.766" style="s2">The needle is being advanced<br />to the biceps muscle.</p>
<p begin="00:05:48.766" end="00:05:52.933" style="s2">You can see the pulsatile<br />axillary artery medial as well.</p>