Development of an Emergency Department Ultrasound Program – Dr. Michael Antonis

Building a Point-of-care Ultrasound Program – Dr. Keith Boniface

See you there!

• Where: George Washington University Hospital, 900 23rd St, NW, room 6111.
• When: 6pm
• Nearest metro: Foggy Bottom (orange or blue line)
• Nearest parking: http://www.gwhospital.com/Directions-Maps
• Main entrance to hospital at street level. Check in with security for a visitor bracelet. Take the main elevators to the 6th floor, turn right after exiting the elevators, walk through door and room will be on right.

Hope to see you there! Please RSVP to this capitolultrasound@gmail.com; you may also call or text 585-230-6462.

“A Director’s Perspective: Starting and Managing an Emergency Ultrasound Program”

Come join us for a valuable evening as Dr. Keith Boniface, director of GW’s emergency ultrasound division, and Dr. Michael Antonis, director of the Georgetown University/Washington Hospital Center’s emergency ultrasound program, share their thoughts and experiences in maintaining and managing their respective programs and fellowships. All are welcome.

Come join us for a valuable evening as Dr. Keith Boniface, director of GW’s emergency ultrasound division, and Dr. Michael Antonis, director of the Georgetown University/Washington Hospital Center’s emergency ultrasound program, share their thoughts and experiences in maintaining and managing their respective programs and fellowships. All are welcome. Please rsvp to CapitolUltrasound@gmail.com so we can get a head count.

The meeting will be held on the 6th floor of the George Washington University Hospital, 900 23rd St, NW, room 6116. Take the main elevators to the 6th floor, turn left after exiting the elevators, then make a quick right around the wall and you’ll see the room.

Come join us for a valuable evening as Dr. Keith Boniface, director of GW’s emergency ultrasound division, and Dr. Michael Antonis, director of the Georgetown University/Washington Hospital Center’s emergency ultrasound program, share their thoughts and experiences in maintaining and managing their respective programs and fellowships. All are welcome. Please rsvp to CapitolUltrasound@gmail.com so we can get a head count.

The meeting will be held on the 6th floor of the George Washington University Hospital, 900 23rd St, NW, room 6116. Take the main elevators to the 6th floor, turn left after exiting the elevators, then make a quick right around the wall and you’ll see the room.

Interscalene approach to brachial plexus Block:

Transducer used: Liner, high frequency probe (13-6 MHz)

Region of anesthesia provided: Shoulder, upper arm, elbow

Indications: Shoulder and elbow dislocations, humerus fractures, large extremity lacerations

Technique: With patient lying supine or sitting, position the probe with marker towards patient’s left shoulder and in midline of neck.

Probe position for interscalene approach to brachial plexus block

Slide probe laterally until middle scalene muscle is visible, which appears as a small “fillet”:

Nerve bundles are seen in cross section between middle and anterior scalene muscles, and appear more hypoechoic than seen in other ultrasound images of nerves, which are typically brighter than surrounding structures.

Approach the nerve bundles with needle “in plane” with ultrasound beam, in longitudinal orientation. Typical amount of anesthesia injected varies by source but is often quoted in the range of 10-30 mL. Known complications of the procedure include intra-arterial injection with development of systemic toxicity, hematoma formation, neuropraxia, Horner’s syndrome from a large volume of anesthesia reaching the stellate ganglion , hoarse voice due to involvement of the recurrent laryngeal nerve, and ipsilateral diaphragmatic paralysis due to proximity of the phrenic nerve.  Due to the possibility of these complications it is recommended that a larger volumes of anesthetic are avoided, that this block is avoided in those with chronic pulmonary pathology, and that bilateral inter-scalene blocks are never performed. Additionally, the more proximal the approach to the block, the higher likelihood of phrenic nerve involvement due to greater likelihood of C3-5 involvement.

Ulnar and Median nerve blocks:

Transducer used: Liner, high frequency probe (13-6 MHz)

Region of anesthesia provided: The Median nerve innervates the volar aspect of the palm and digits 2, 3, and half of 4, and the distal dorsal aspect of the same fingers.  The ulnar nerve innervates the remaining half of the fourth digit and all of the fifth, as well as the hypothenar eminence .

Indications: large, avulsed finger and hand wounds, industrial injuries involving multiple digits

Technique: Using a high frequency transducer, both the median and ulnar nerves can be found above and below the elbow in cross section:

Probe position to find median nerve above elbow

Probe position to find ulnar nerve below elbow

Probe position to find median nerve below elbow

Probe position to find ulnar nerve above elbow

The median nerve appears as a hyperechoic bundle between the deep brachial vessels…

Median nerve lateral to deep brachial artery; probe position above elbow

The ulnar nerve appears as a hyperechoic bundle in cross section, scanned here above the elbow at the level of the triceps muscle

Red arrow points to ulnar nerve running through cubital fossa

Remember to thoroughly document a neurologic exam prior to performing any nerve block. Complications of these two blocks include hematoma formation, neuropraxia, and arterial puncture, but these blocks are fairly well-tolerated and low-risk.

Popliteal nerve block:

Transducer used: Liner, high frequency probe (13-6 MHz)

Region of anesthesia provided: The sciatic nerve becomes the popliteal nerve in the popliteal fossa, dividing into the tibial nerve posteriorly and the common peroneal nerve laterally as it traverses distally. The region of anesthesia provided is to the distal two thirds of the lower extremity, with the exception of the medial aspect of the leg. Cutaneous innervation of the medial leg below the knee is provided by the saphenous nerve:

With the patient supine, scan through the popliteal fossa in cross section:

Look for the popliteal nerve as the hyperechoic bundle of fibers lateral to the popliteal artery. Distribution of the anesthetic above the level of the bifurcation provides anesthesia to both the tibial and common peroneal divisions:

Red arrow points to thick bundle of popliteal nerve in fossa; lateral to popliteal artery

Complications include hematoma formation, neuropraxia, and arterial puncture, as described with the ulnar and median nerve blocks above. Additionally, a special consideration with the popliteal nerve block is the development of pressure necrosis of the heel in the setting of longer acting anesthetics such as Bupivicaine. Be aware that pressure ulcers can develop in less than 30 minutes, and care should be taken to elevate the lower extremity with stacked sheets or linens beneath the calf to remove pressure from the heel.

Additional resources from Mr. Rainville include a recommendation for the following text, “Ultrasound-Guided Regional Anesthesia and Pain Medicine”, by P. Bigeliesen, et al.

Also see an excellent collection of slides describing Ultrasound Guided Nerve Blocks by our own Dr. Liu of the GWU EM department. Hope to see you at our next meeting!

A RUQ ultrasound was done to assess the gallbladder:

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Figure 1: A mid-range frequency, phased array probe is used to assess the gallbladder in its long axis.

Figure 2: A dilated common bile duct is seen here. Note that a “normal” measurement for the CBD is considered to be less than 6mm; some providers allow 1 mm per decade. A patient who is s/p cholecystectomy may have a CBD that is dilated up to 1 cm.

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Figure 3: In this view we see the gallbladder in short axis. We see peristaltic movement of bowel to the right of the gallbladder, but pay attention to the hypoechoic area seen within the liver tissue to the left of the gallbladder.

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Figure 4: Upon closer inspection of the liver, we see multiple heterogeneous areas suspicious for metastatic disease.

The patient went for ERCP, and a pancreatic mass was noted. The incidental findings in the hepatic tissue were noted on QA, or quality assurance review, highlighting the importance of not only noting the area intended for exam, but also the surrounding tissue as normal or abnormal. “Incidentalomas” may be frequently identified when examining the RUQ on ultrasound; in one report a nonbiliary source of pain was identified in 21% of cases (1). Although specific characterization of these findings is often outside the scope of emergency ultrasound, EUS serves as a reasonable first line screening modality for identification of RUQ pathology.

1. Shuman WP, Mack LA, Rudd TG, et al. Evaluation of acute right upper quadrant pain: sonography and 99m-Tc-PIPIDA cholescintigraphy. AJR Am J Roentgenol. 1982; 139:61-64.

Recommended reading: Leeuwen MV, Nederend J, Smithuis R. What to do with incidentally found lesions in the liver? Radiology department of the University Medical Centre of Utrecht, the Leiden University and the Rijnland Hospital, Leiderdorp, the Netherlands

View link here: www.radiologyassistant.nl/en/45a5e818c709d

Figure 1: Free fluid seen in RUQ

Figure 2: Free fluid seen in LUQ

Figure 3: Free fluid seen in pelvis on TV ultrasound

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Figure 3: Grossly positive FAST exam with free fluid in the LUQ

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Figure 4: Free fluid seen around R adnexa

Given these findings, a pregnancy test was performed and found to be positive. OB/GYN was consulted and emergently took the patient to the OR where laparoscopic exploration revealed a tubal pregnancy. The patient underwent salpingectomy and recovered succesfully. In the case of undifferentiated hypotension in a young woman, ectopic pregnancy is high on the differential. A 2008 study published in Academic Emergency Medicine demonstrated a significant correlation between the presence of free fluid in Morrison’s pouch on FAST exam and the need for definitive operative management in the setting of extrauterine pregnancy (1). The average time of the scans in this study was less than five minutes, demonstrating potential to significantly decrease ER to OR time in the setting of an unstable patient requiring operative intervention.

Recommended reading: (1) Moore C, Todd W, O’Brien E, et al. Free Fluid in Morison’s Pouch on Bedside Ultrasound Predicts Need for Operative Intervention in Suspected Ectopic Pregnancy. Academic Emergency Medicine 2008; 14(8):755-758.

Figure 1: RUQ with no free fluid seen on FAST exam

The LUQ and pelvis were also negative for free fluid or noted abnormalities. A four chamber view of the heart performed as part of the FAST exam is shown below:

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Figure 2: Apical 4-chamber view of the heart

Note the presence of a hyperechoic mass-like structure in the right atrium; concerning for thrombus vs. mass. Cardiology was then consulted and a complete TTE was done in ED confirming the presence of an atrial mass.  The patient was  admitted for further work-up, where a CT of the chest revealed a 4 cm filling defect in the right atrium concerning for a myxoma. The CT also revealed what appeared to be lytic lesions in the spine.  The patient was found to be HIV positive, and on hospital day 5 underwent radical resection of the right atrium, described as a spindle cell carcinoma on the initial pathology report. The final report from Johns Hopkins pathology revealed grade 3 Angiosarcoma.

Cardiac tumors are uncommon, usually benign myxomas, although lipomas and fibromas may occur.  Rare primary malignant tumors include sarcomas (especially angiosarcoma), as well as mesotheliomas and lymphoma.  Metastatic tumors and venous extension (renal, adrenal, and liver cancer) may also involve the heart.  Myxomas usually attach to interatrial septum on the left, and are slow growing masses that often present with embolic phenomenon.  Surgery is curative in most cases; 5% recur.  Angiosarcomas typically involve the pericardium and left atrium, and may cause obstruction with signs and symptoms of R sided heart failure.  Surgery is the mainstay of therapy, combined with radiation, chemo, and immunotherapy.  Mean survival for most primary cardiac sarcomas is less than 1 year.

The practitioners in this case imaged the heart as part of the FAST exam and were able to identify this extremely unusual pathology.  And while they were not initially suspicious of a cardiac etiology of his symtoms, their use of an alternative imaging modality provided important information about the underlying cause of the patient’s symptoms.  This case highlights the fact that the presence of persistent symptoms in the face of recent negative imaging should prompt a re-evaluation of the patient’s complaint.

Recommended reading: Jones AE, Tayal VS, Kline JA. Focused training of emergency medicine residents in goal-directed echocardiography: a prospective study. Acad Emerg Med. 2003; 10: 1054-1058.

Special thanks to Dr. Ali Pourmand and Dr. Pete Dowiatt for their excellent clinical care and scanning skills!