[Music] the quadrus lorum block or ql block is a blockade of the intercostal nerves of the abdominal wall that provides pain control for a variety of abdominal and other procedures in this video we'll discuss the anatomy Sono anatomy and technique for the anterior approach to the qal block and offer some tips for Success the quadrus lumborum muscle stretches from the ilite crest to the 12th rib with medial attachments to the lumbar transverse processes it lies anterior to the erector spiny muscle and posterior to the Seas major muscle the ventral Rite of the lower thoracic nerves run along its anterior surface and local anesthetic placed here in the potential space between soos and ql will anesthetize those nerves supplying the abdominal wall in this cross-section of the abdominal wall we see the transverses abdominus muscle the internal and external oblique muscles and a latissimus dorsy muscle superficially adjacent to the vertebra we find the erector spining muscle posteriorly the SE major muscle tucked in beside the vertebral body and the ql muscle extending laterally from the tip of the transverse process the ventral RI of the lower thoracic nerves travel between the Seas and ql then across the anterior surface of ql before jumping into the to plane this gives us several opportunities to block these nerves and the three common approaches are named due to the relation to the ql muscle the lateral approach is very similar to a tap block where local anesthetic is placed at the lateral aspect of ql the posterior approach targets the fascial plane posterior to ql with the hope that the local spreads medially and or anteriorly the anterior approach targets the intermuscular fascial plane between ql and seis major while there are pros and cons to each approach the one that we favor for abdominal surgery is the anterior approach in our setting this achieves the most extensive sehil spread of local anesthetic and the best overall effect of the three approaches other names for this approach are the ql3 and the trans muscular ql block one of the reasons for the success of the anterior ql is the fact that local anesthetic will travel in a sephila direction and enter the paravertebral space of the lower thorax via the lumbocostal arch here we've made the Seas muscle slightly transparent and we can see the Gap here outlined in yellow this facilitates blockade of the upper reaches of the abdomen and contributes to visceral analgesia following low thoracic sympathetic block the ql is a volume block and with 30 MS of dilute local anesthetic on each side you should see a sensory block of most of the anterior and lateral abdominal wall as well as some visceral coverage we use this block for abdominal pelvic cases where we require a broad coverage of the abdomen examples include coloral surgery cesarian delivery prostectomy nephrectomy and gym procedures it's nice for robotic surgery when you have multiple port sites scattered over various quadrants because the ql usually gets a T12 and L1 branches people have also used ql blocks for hip surgery this block can easily be done in the sitting and prone positions although we most commonly perform the Block in the lateral position for ergonomics and patient Comfort a curval linear transducer is placed on the posterior lateral abdomen at the level of the iliac crests the probe is rotated so the beam is directed back towards the patient's spine the needle is Advanced from the posterior or medial side of the probe often near the spinal midline both sides can be blocked with one position this way with no need to flip the patient over here's a typical ql sonogram with the ultrasound beam directed obliquely at the paraspinal structures we see the ql muscle extending laterally off the transverse process with the Seas deep to it the ql usually looks like a flag flying from the flag pole of the TP further anterior and deeper you'll appreciate motion associated with the retrop parum sometimes the kidney can be observed bobbing in and out of the picture suffice it to say that's a no-fly zone the target fascia plane is usually quite bright because of its perpendicular orientation to the beam the needle will be Advanced from the medial or posterior aspect the nomenclature of this block has evolved and has become quite contentious at times maybe I'm just hungry but I think this block should be named for the stake that frankly looks exactly like the picture we're after let's get Porter House block trending shall we because we deal with a variety of body shapes and sizes it's convenient to use bones as a starting point for scanning rather than soft tissue planes here we are in the posterior midline and we can see the shadow of the spinus process as we move off laterally we see first the articular processes then the transverse process sticking out laterally the probe is rotated so the beam is directed back towards the paraspinal area giving us a nice view of the TP flag pole the ql flag and the Seas muscle deep to that okay so let's see this block we see the needle passing through the erector spining muscle then ql after a pop through the Deep surface of the ql a test injection with saline shows that we're in the right plane and the Seas muscle starts to be pushed down and peeled off the underside of ql you can see the local anesthetic swirling in the potential space we're creating between the ql and seas there is some lateral spread but the elastic recoil of the poorly compliant muscles in this part of the trunk will help to squeeze the local seilat you can see the retrop parat Neal contents moving with respiration just lateral to the needle position it's important to ensure that the needle tip is truly between the Q and SE is muscles for the block to be effective and not between ql and the retrop paral fat here see the local anesthetic has pushed the two muscles apart nicely here are some ql tips for Success first we do like to rely on Imaging of the transverse process to Anchor our image and easily identify the ql muscle however you don't want that bony structure to be in your needle path a slight shift sead will take the TP out of the picture leaving you with a clear shot to the Target second there have been cases of quadriceps weakness following ql block probably due to local anesthetic within the Seas muscle causing a lumbar plexus block I like to use nerve stimulation to help keep my tip out of ql I'll turn the current intensity up to one or 1.5 milliamps then watch on the screen as my needle passes through the erector spin a then the ql muscle watching for the muscles to Twitch through direct muscular stimulation when the needle passes through ql it'll stop twitching if the SE muscle starts twitching on the screen your tip is too far pull back slowly until you're not directly stimulating either muscle that way you're likely to be in the correct plane lastly you can identify the ql muscle scanning from the anterior aspect here we see the tap muscles coming to an end and the ql muscle lying deep to the internal oblique muscle this strategy is better suited to finding the ql muscle for the lateral and posterior approaches as a plane between the ql and seist doesn't light up quite as nicely especially in challenging patients relying on bony sonographic landmarks is a reliable path to success