<p begin="00:00:07.292" end="00:00:09.121" style="s2">- [Voiceover] A linear array transducer</p>
<p begin="00:00:09.121" end="00:00:11.513" style="s2">with a nerve exam type is used to perform</p>
<p begin="00:00:11.513" end="00:00:14.888" style="s2">an ultrasound-guided,<br />interscalene nerve block.</p>
<p begin="00:00:14.888" end="00:00:18.497" style="s2">The target depth is approximately<br />one to three centimeters</p>
<p begin="00:00:18.497" end="00:00:20.715" style="s2">in an 80-kilogram adult.</p>
<p begin="00:00:20.715" end="00:00:24.654" style="s2">The patient is positioned in<br />a 45-degree reclining position</p>
<p begin="00:00:24.654" end="00:00:26.373" style="s2">with a pillow under their head</p>
<p begin="00:00:26.373" end="00:00:29.536" style="s2">and the head turned toward<br />the contralateral side.</p>
<p begin="00:00:29.536" end="00:00:31.900" style="s2">The examination begins by finding</p>
<p begin="00:00:31.900" end="00:00:34.916" style="s2">the supraclavicular region<br />of the brachial plexus</p>
<p begin="00:00:34.916" end="00:00:36.709" style="s2">as a landmark technique.</p>
<p begin="00:00:36.709" end="00:00:39.039" style="s2">The transducer is placed posterior</p>
<p begin="00:00:39.039" end="00:00:41.013" style="s2">to the midpoint of the clavicle</p>
<p begin="00:00:41.013" end="00:00:42.373" style="s2">with the orientation marker</p>
<p begin="00:00:42.373" end="00:00:46.540" style="s2">directed to the patient's right<br />at a three-o'clock position.</p>
<p begin="00:00:49.085" end="00:00:51.056" style="s2">The subclavian artery is seen</p>
<p begin="00:00:51.056" end="00:00:53.399" style="s2">as a round, pulsatile structure</p>
<p begin="00:00:53.399" end="00:00:56.778" style="s2">superior to the bright<br />reflection of the first rib.</p>
<p begin="00:00:56.778" end="00:01:00.337" style="s2">The pleura is seen as a<br />bright, hyperechoic reflection</p>
<p begin="00:01:00.337" end="00:01:03.590" style="s2">deep to or at the same<br />depth as the first rib.</p>
<p begin="00:01:03.590" end="00:01:07.432" style="s2">The nerves of the brachial<br />plexus are posterior or superior</p>
<p begin="00:01:07.432" end="00:01:09.681" style="s2">to the subclavian artery.</p>
<p begin="00:01:09.681" end="00:01:12.728" style="s2">The nerves appear as<br />hypoechoic dark circles</p>
<p begin="00:01:12.728" end="00:01:14.814" style="s2">within the bright hyperechoic fascia</p>
<p begin="00:01:14.814" end="00:01:17.115" style="s2">surrounding the brachial plexus.</p>
<p begin="00:01:17.115" end="00:01:21.158" style="s2">To identify the interscalene<br />region of the brachial plexus,</p>
<p begin="00:01:21.158" end="00:01:23.987" style="s2">slowly slide the transducer up the neck.</p>
<p begin="00:01:23.987" end="00:01:26.568" style="s2">The interscalene muscles<br />will frame the nerves</p>
<p begin="00:01:26.568" end="00:01:29.020" style="s2">within the interscalene groove.</p>
<p begin="00:01:29.020" end="00:01:30.848" style="s2">The nerves will change in shape</p>
<p begin="00:01:30.848" end="00:01:34.236" style="s2">from a grape-like cluster in<br />the supraclavicular region</p>
<p begin="00:01:34.236" end="00:01:37.710" style="s2">to a chain-link appearance<br />in the interscalene groove.</p>
<p begin="00:01:37.710" end="00:01:42.445" style="s2">The C5 and C6 nerve roots<br />appear as three circles.</p>
<p begin="00:01:42.445" end="00:01:45.348" style="s2">The hypoechoic pulsatile carotid artery</p>
<p begin="00:01:45.348" end="00:01:48.969" style="s2">will appear medial to the<br />anterior scalene muscle.</p>
<p begin="00:01:48.969" end="00:01:50.345" style="s2">The needle can be advanced</p>
<p begin="00:01:50.345" end="00:01:53.771" style="s2">using an in-plane or<br />out-of-plane technique.</p>
<p begin="00:01:53.771" end="00:01:55.547" style="s2">For an in-plane technique,</p>
<p begin="00:01:55.547" end="00:01:58.220" style="s2">the needle is positioned<br />one to two centimeters</p>
<p begin="00:01:58.220" end="00:02:02.344" style="s2">lateral to the transducer and<br />advanced under the transducer</p>
<p begin="00:02:02.344" end="00:02:05.776" style="s2">until the tip is just<br />posterior to or between</p>
<p begin="00:02:05.776" end="00:02:07.943" style="s2">the C5 and C6 nerve roots.</p>
<p begin="00:02:08.909" end="00:02:11.627" style="s2">The local anesthetic is<br />injected incrementally</p>
<p begin="00:02:11.627" end="00:02:13.691" style="s2">close to the nerve roots.</p>
<p begin="00:02:13.691" end="00:02:15.098" style="s2">The needle can be redirected</p>
<p begin="00:02:15.098" end="00:02:18.749" style="s2">if the spread of local anesthetic<br />is not deemed adequate.</p>
<p begin="00:02:18.749" end="00:02:21.425" style="s2">It is not necessary to<br />have local anesthetic</p>
<p begin="00:02:21.425" end="00:02:24.665" style="s2">anterior and posterior to the nerve roots.</p>
<p begin="00:02:24.665" end="00:02:28.832" style="s2">Posterior spread only of<br />local anesthetic is effective.</p>