VOTW: Can’t shrug this one off!

Hello all! This week’s VOTW is brought to you by myself!

Hospital course

An 18 y/o M presented after falling off his skateboard causing him to land on his left shoulder. The XR showed a posterior shoulder dislocation, seen in the XR below where we can see the classic light bulb appearance of the humeral head.

Ultrasound

The left shoulder was scanned with ultrasound, which is shown below.

Note that close proximity of the humeral head to the probe (more superficial), which is indicative of a posterior shoulder dislocation. Also note that the glenoid fossa is not seen well, indicating that the humeral head is not articulating well with the glenoid.

An US-guided interscalene nerve block was completed to relieve the patient’s pain. The target is the brachial plexus cords seen in the image above between the middle and anterior scalene muscles.

In the above clip, we can see the needle entering in-plane lateral to medial with injection of local anesthetic within the interscalene space, surrounding the brachial plexus.

Case Conclusion

After the interscalene block, the patient had great pain control and the shoulder was able to be reduced successfully without any procedural sedation!

This ultrasound of the shoulder was obtained post-reduction. Here we can see that the humeral head is articulating directly with the glenoid.

In this clip, we can see the glenohumeral joint with the humeral head moving well in normal alignment as the shoulder adducts and abducts.

Posterior shoulder dislocation

• A posterior shoulder ultrasound scan is done by placing the probe just over the scapular spine in a transverse plane, with the probe marker towards the patient’s left.

• A posterior shoulder dislocation will show the humeral head displaced closer to the probe (appears more superficial on the screen). Also, the humeral head will not be articulated with the glenoid fossa.

• An US-guided interscalene block can be performed in the ED as a replacement for procedural sedation prior to shoulder reduction as seen with this patient! The interscalene block covers the shoulder and proximal humerus. The probe is placed 2-3 cm superior to the clavicle and the target is the brachial plexus which is commonly referred to as the “stoplight” sign in this view because of its 3 circular hypoechoic structures found between the middle and anterior scalene muscles.

Happy scanning!

Sono team

Resources to review:

• https://www.thepocusatlas.com/brachial-plexus/#interscalene

• https://www.acep.org/emultrasound/newsroom/apr2021/pocus-for-shoulder-pain-in-the-emergency-department

• https://www.acepnow.com/article/use-point-care-ultrasound-identify-shoulder-dislocation/

VOTW: “D”-oh! What a heart!

Hello all! This week’s VOTW is brought to you by myself.

Hospital course

30 y/o M presents to the ED after 2 syncopal episodes. He had 10 days of worsening dyspnea on exertion with chest pressure and palpitations. He flew to California 1 month ago and returned yesterday.  

In the parasternal short view of the heart above, we see two cardiac chambers, the right ventricle (RV) and the left ventricle (LV). We can see flattening of the interventricular septum towards the LV chamber, creating a “D”-shaped LV (labelled above).

View the attached clip to see the LV take on a shape of the letter “D” with each contraction! Also note that the RV is dilated and appears larger in size than the ”D”-shaped LV.

The clip above shows a parasternal short view of a normal heart. Notice that the left ventricle appears circular, and the right ventricle forms a smaller crescent-shape surrounding the left ventricle.

Case Conclusion

CT imaging showed pulmonary emboli within the bilateral pulmonary arteries and dilatation of the right atrium and right ventricle associated with right heart strain.

Thrombectomy was deferred because patient was hemodynamically stable. He was started on a heparin infusion in the ED and then admitted.   

Right heart strain

·       Pulmonary embolism can cause an acute increase in pulmonary pressures and right ventricular afterload that causes increased right heart strain. Focused ultrasound has been shown to be both highly sensitive and highly specific in detecting anatomical changes of the heart seen with right heart strain.

·       “D-sign” is a finding suggestive of right heart strain seen on the parasternal view of the heart. Increased right ventricular pressures cause bowing of the interventricular septum into the LV, causing the “D”-shaped LV to form.

·       Other findings suggestive of right heart strain include increased RV size, McConnell’s sign, and TAPSE.

Happy scanning!

Sono team

PS: just in case nobody gets it, the subject line pun is a Simpsons reference!

Resources to review:

·       https://www.thepocusatlas.com/right-ventricular-dysfunction/

·       https://everydayultrasound.com/blog/category/Right+Ventricular+Strain

·       https://www.acep.org/sonoguide/basic/cardiac

VOTW: Let’s put a knee-dle in that knee!

Hello all! This week’s VOTW is brought to you by myself.

Hospital course

50 y/o F presents to the ED with several weeks of lower back and left knee pain. Left knee is swollen and tender with palpation. She limps when ambulating due to the pain. Bedside ultrasound of the knee joint is shown below.

In the image above, the probe is placed over the suprapatellar space with a long-axis view. The femur is seen below, with a layer of dark anechoic effusion visible between the quadriceps tendon and the prefemoral fat pad.

Once the suprapatellar effusion was identified, the probe was rotated 90° into a transverse view of the knee, and the needle was inserted lateral to medial using an in-place approach. In the image above you can see the needle tip enter the effusion underneath the quadriceps tendon. The needle is the hyperechoic straight line in the left image, which is labelled with a white arrow in the right image.

In the clip above we can see this ultrasound-guided in-plane needle insertion with the needle tip entering the suprapatellar effusion.

In this clip, we can see the effusion shrink in size as the synovial fluid is actively aspirated through the needle!

Case Conclusion

The synovial fluid specimen was sent to the lab, and septic arthritis was ruled out. The patient’s left knee pain significantly improved after the arthrocentesis and she was discharged.

Ultrasound-guided knee arthrocentesis

·       While this procedure can be performed blind, the use of ultrasound improves accuracy, improves pain scores, and allows aspiration of more synovial fluid.

·       The patient should be positioned supine with the knee in 15-20° of flexion.

·       Begin by identifying a suprapatellar effusion by placing the linear probe superior to the patella with the marker oriented cephalad (long axis view of the knee). A joint effusion will look like an anechoic stripe within the joint space deep to the quadriceps tendon.

·       Once you identify a drainable effusion, rotate the probe 90° to obtain a transverse view (short axis view of the knee). A lateral to medial in-plane technique should be used to guide the needle tip into the joint effusion.

·       Remember to use a sterile ultrasound probe cover!

·       Ultrasound-guided arthrocentesis can be used to drain effusions from any joint, with commonly aspirated joints including knees, hips, shoulders, wrists, elbows, and ankles.

Happy scanning!

Sono team

Resources to review:

·       https://www.acep.org/sonoguide/procedures/arthrocentesis

·       https://mskultrasound.net/arthrocentesis-of-the-knee/

·       https://coreultrasound.com/knee-aspiration-and-injection/