Capitol Ultrasound » GWU Department of Emergency Medicine

March 30th “Directors Perspective” Discussion: huge success!

admin — Sun, 03 Apr 2011 02:39:47 +0000

Dr. Keith Boniface and Dr. Mike Antonis provided fantastic insight for the well-attended March 30th Capitol Ultrasound meeting. Both described their experiences creating and managing growing point-of-care ultrasound programs, with fantastic input from the audience. See presentations below. All interested in a podcast of the evening, please email capitolultrasound@gmail.com.

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

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

March 30th Capitol Ultrasound group: Room change

admin — Tue, 29 Mar 2011 18:21:17 +0000

The meeting will be held in room 6111, rather than 6116. Directions same as previously posted, but exit elevator to right, go through door, room will be on right. Signs will be posted. All other information same as previous.

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.

Next Capitol Ultrasound meeting, March 30th at 6pm

admin — Wed, 09 Feb 2011 01:37:06 +0000

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

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.

Tonight’s Capitol Area Ultrasound meeting: CANCELLED

admin — Thu, 27 Jan 2011 20:25:55 +0000

Due to inclement weather, tonight’s Capitol Ultrasound meeting, “Starting and Maintaining an Ultrasound Program”, has been canceled due to inclement weather. Check back for rescheduled date. See you then!

Next Capitol Ultrasound meeting: Thursday, Jan 27th, 6pm

admin — Mon, 10 Jan 2011 14:19:02 +0000

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

October Capitol Ultrasound meeting: Ultrasound-Guided Regional Anesthesia

admin — Tue, 02 Nov 2010 16:42:40 +0000

Our last Capitol Ultrasound meeting was a huge success, with the Georgetown EM department graciously hosting the event in the simulation lab at Washington Hospital Center. As usual Michelle Saylor of Sonosite organized a great event, and with her colleague Don Rainville presented a fantastic hands-on session reviewing several commonly used ultrasound-guided nerve blocks. Below you’ll find a summary and photos of the 4 nerve blocks discussed: An interscalene approach to a brachial plexus block, a median nerve block, an ulnar nerve block, and a popliteal nerve block, as well as some additional resources for those interested in reading further about the subject. Join us at our next Capitol Ultrasound meeting for more exciting educational opportunities and great cases!

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!

Ultrasound 101 for GW EM faculty

admin — Thu, 29 Oct 2009 07:13:03 +0000

Abdominal pain: repeat visit

admin — Thu, 05 Mar 2009 17:21:06 +0000

A 41 year old male presented to the ED with diffuse abdominal pain. Vital signs were normal and bloodwork was unremarkable for abnormalities. Past medical history was benign per the patient. A CT of the abdomen and pelvis with PO and IV contrast was ordered due to the severity of pain on exam, which demonstrated”a 3.0 cm mass with peripheral ring enhancement during arterial phase in the right hepatic lobe. The lesion has become isodense in the parenchymal phase. This is likely a cavernous hemangioma.” The patient was discharged home and set up for follow up in the medical clinic. Two weeks later he returned to the ED, stating that the pain had returned and was now radiating to his back. He again denied medical problems, alcohol, tobacco, or recreational drug use. His vital signs were normal and his exam again reveals diffuse abdominal tenderness to palpation, with no rebound or guarding. Lab work was unchanged. What would you do next?

The resident and attending performed a FAST exam to assess for free fluid:

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!

Syncope with a history of Marfan’s Disease…

admin — Tue, 24 Feb 2009 04:40:23 +0000

A 53 yo woman collapsed in a crowd while celebrating inuaguration day on the mall in January of 2009. EMS was called by bystanders, who arrived to find the patient supine and in severe distress. She was able to reveal a medical history of Marfan’s disease, then became hypotensive and diaphoretic. She was immediately transported to the emergency department, where she was noted to be bradycadic, hypotensive, and unresponsive. She was intubated, central venous access was obtained, and a comprehensive workup including a chest and abdominal CT was performed. A bedside echocardiogram and abdominal ultrasound to evaluate the aorta were also performed. Initially no contrast was seen within the aorta, limiting the study for visualization of dissection or an intimal flap. However, upon repeat evaluation, the study reveals a complex dissection flap extending from the ascending aorta to bilateral iliac arteries, involving the L subclavian, common carotid, and renal artery. These bedside ultrasound images were obtained within the initial 20 minutes of the resuscitation:

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Figure 1: Transverse view of the descending aorta. A low frequency, phased array probe is used for all images. Here the probe marker is oriented toward the patient’s R shoulder. Note the hyperechoic dissection flap seen in this cross-sectional view of the vessel.

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Figure 2: Longitudinal view of the descending aorta. In this view the bright dissection flap is seen extending the length of the vessel at its posterior aspect.

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Figure 3: A suprasternal view of the ascending aorta is obtained by placing the probe in the patient’s suprasternal notch, marker oriented straight up toward the patient’s head. The dissection flap is visible in this view as well, mandating surgical involvement.

Conclusion: The patient was taken emergently to the OR where she experienced complete hemodynamic collapse. Resuscitative efforts were unsuccessful, and she eventually died of complications of her disease.

Recommended reading: Bilku R, Steadman C, Jordan P. Acute deBakey type III (or Stanford type B) aortic dissection diagnosed by transthoracic
echocardiography. Journal of American Society of Echocardiography. 2008; 21(9): 1080-1083.

Special thanks to Dr.s Annette Dorfman and Jeremy Berman for their scanning skills and excellent clinical care!