UMEM Educational Pearls - By Alexis Salerno

Ectopic pregnancy ranges from 3 to 13% in symptomatic first-trimester ED patients. 

The discriminatory zone is defined as the level of Bhcg above which an intrauterine pregnancy can be reliably detected using ultrasound.  (1,500 mIU/mL for transvaginal ultrasound and 3,000 mIU/mL for transabdominal ultrasound)

One study found that an intrauterine pregnancy was visualized with as low as 1,440 mIU/mL and patients with an interdeterminate pelvic ultrasound who were found to have an ectopic pregnancy had a Bhcg greater than 3,000 mIU/mL only 35% of the time. 

 

Bottom Line: If you have a symptomatic patient with an empty uterus and a bhcg above the discriminatory zone, they have a higher risk for ectopic pregnancy. However, if your patient is symptomatic, they should still have further evaluation for ectopic pregnancy even if they have a bhcg lower than the discriminatory zone. 

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Category: Gastrointestional

Title: POCUS for Appendicitis

Keywords: POCUS, Appendicitis, Pregnancy (PubMed Search)

Posted: 7/3/2023 by Alexis Salerno, MD
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POCUS can be used to screen for appendicitis.

A recent study showed a sensitivity of 66.7% (CI 95% 47.1–82.7), and a specificity of 96.8% (CI 95% 83.3–99.9) during pregnancy, with the highest sensitivity in the first trimester. 

2 methods to locate the appendix are:

1) have your patient point to the area where it hurts the most

2) perform a lawnmower technique over the right lower quadrant looking for the right psoas mucle and the iliac vessels. The appendix will usually be near these structures. 

Sometimes it is easiest to use your curvilinear probe to identify an area of inflammation and then change to the linear probe for better visualization. 

On ultrasound, appendicitis is defined as a non-compressible blind pouch with an outer diameter greater than 6 mm. On short axis the inflammed appendix will look like a target sign:

 

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Category: Orthopedics

Title: Fascia Iliac Block for Hip Fractures

Keywords: POCUS, Hip Fractures, Nerve Blocks, Administration (PubMed Search)

Posted: 6/26/2023 by Alexis Salerno, MD (Updated: 10/10/2024)
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The use of a fascia iliaca compartment block has been shown to reduce pain, decrease length of stay and decrease the opiate requirements for patients with hip fractures.  

 

Check out this page on how to perform this procedure.  

 

Fascia iliac blocks can be challenging to implement routinely in the emergency department. Studies show that 2.5% of eligible patients, despite departmental implementation, receive a block.  

 

One recently published article showed that large scale multi-disciplinary implementation can increase the use of fascia iliac blocks. After implementation, the study team found that 54% of eligible patients received a fascia iliac block.  

 

This article is interesting as it provides helpful resources including physician and nursing protocols for performing this block. 

 

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Category: Vascular

Title: POCUS for Abdominal Aortic Aneurysm

Keywords: POCUS, AAA, (PubMed Search)

Posted: 6/19/2023 by Alexis Salerno, MD (Updated: 10/10/2024)
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It is difficult to diagnosis a ruptured AAA with POCUS. However, based on one systematic review and meta-analysis, POCUS has a sensitivity of 97.8% and a specificity of 97% for diagnosing AAA in patients supsected of having a ruptured AAA. 

Remeber:

  • The normal abdominal aorta should measure under 3 cm.
  • The proximal iliacs should measure under 1.5 cm. 
  • Measure the aortic diameter from leading edge to leading edge. 

Laslty, make sure you are measuring the aortic wall and not a mural thrombus. 

 

 

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Category: Orthopedics

Title: POCUS for Knee Pain

Keywords: POCUS, Knee Pain, Tendon Rupture (PubMed Search)

Posted: 6/5/2023 by Alexis Salerno, MD
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Question

Pt presents to the emergency department with knee pain.

You decide to ultrasound the proximal knee. You place your ultrasound probe in the midline of the knee with your probe marker towards the patient's head. 

What is the diagnosis?

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The answer is a quadriceps tendon rupture with femur fracture.

 

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Category: Administration

Title: Using M-Mode for Lung Ultrasound

Keywords: POCUS, Lung Ultrasound, Pneumothorax (PubMed Search)

Posted: 5/29/2023 by Alexis Salerno, MD
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We hope that you enjoy your Memorial Day!

Don't forget your Sandy Beach Sign vs Barcode Sign of Lung Ultrasound:

Normal lung will have good pleural sliding. When you image the lung with M-Mode it looks like a Sandy Beach. 

 

 

 

 

 

 

 

 

 

 

 

A lung with a pneumothorax will have poor lung sliding. When you image the lung with M-Mode it looks like a classic barcode or "stratosphere sign."

Make sure that you are on "Lung Mode" or decrease the gain to better image the movement of the pleural line. The negative predictive value for lung sliding on ultrasound is 99%. This means that if you see lung sliding you do not have a pneumothorax in that area. However, lung sliding is affected by certain conditions such as blebs, pulmonary fibrosis, pleural adhesions and right mainstem intubation. So, like any other radiology study, clinically correlate! 

Thinking about placing a chest tube or have a patient with multiple rib fractures? Take a look at how to perform a Serratus Anteror Plane Block here: https://www.thepocusatlas.com/thoracoabdominal-blocks#Serratus

 

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Category: Administration

Title: Femoral arterial doppler during cardiac arrest

Keywords: POCUS, Cardiac Arrest, Arterial Doppler (PubMed Search)

Posted: 5/15/2023 by Alexis Salerno, MD (Updated: 10/10/2024)
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Did you know that you can use the linear probe with pulse wave (PW) doppler over the femoral artery to look for a pulse during CPR pauses? 

 

Well, the researchers of this article took this skill one step further to evaluate if they could use the femoral artery PW doppler while CPR was in progress to look for signs of a pulse.  

 

The authors found that: 

- pulsations due to compressions were organized with uniform pulsations.  

- when there was also native cardiac activity, the pulsations were nonuniform and may have an irregular cadence 

 

Although there were several limitations, Arterial doppler was 100% specific and 50% sensitive in detecting organized cardiac activity during active CPR.  

 

Take Home Point: Take a look at your arterial doppler for signs of organized cardiac activity during a resuscitation. 

 

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Category: Cardiology

Title: FOCUS for RWMA

Keywords: POCUS, ACS, Regional Wal Motion Abnormality, Ultrasound (PubMed Search)

Posted: 5/1/2023 by Alexis Salerno, MD (Updated: 10/10/2024)
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In this study the researchers looked at patients presenting to the emergency department with high suspicion for ACS and explored if Regional Wall Motion Abnormality (RWMA) evaluation by EPs was associated with occlusion myocardial ischemia (OMI).

FOCUS identified RWMA in 87% of patients with coronary angiography proven OMI. With a sensitivity of 94%, specificity 35%, and overall accuracy of 78%.  

The authors concluded that using FOCUS can have good utility when a patient is high risk for OMI and has an equivocal ekg. However, if RWMA is not present, physicians should still continue with work up such as cardiac catheterization.  

To evaluate RWMA it is easiest to: 

  • Obtain a parasternal short axis at the level of the papillary muscles 
  • Place your finger on the ultrasound machine in the middle of the LV and watch the walls contract towards your finger 
  • The walls should contract equally towards your finger 

For more information check out this ACEPnow article: https://www.acepnow.com/article/detect-cardiac-regional-wall-motion-abnormalities-point-care-echocardiography/?singlepage=1

 

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