Point of Care Ultrasound

Vimeo Channel for Lectures

2011-10-24T13:54:00.003-04:00

Hi Everyone,

Will be using vimeo.com to upload lectures and other long videos. ACEP lecture on blocks already uploaded! Go to http://vimeo.com/mikestone to check it out. Will post here when new videos uploaded.

Ulnar Nerve Block Tutorial

2011-03-14T22:32:00.001-04:00

New tutorial available via the Philips website at

http://www.healthcare.philips.com/main/education/ultrasound/emergency_medicine_cc

Enjoy!

TAP Block for Abdominal Wall Abscess i&D

2011-01-22T03:57:00.004-05:00

Another installment, this one on the transversus abdominis plane block or TAP block. Check it out...

Ulnar Nerve Block for Boxer's Fracture

2011-01-22T03:50:00.003-05:00

Another installment with a slick way to deal with pain control for reduction of hand fractures...

Interscalene Block for Deltoid Abscess

2010-12-21T23:28:00.005-05:00

Hi everybody...

Another installment in the Emergency Ultrasound Nerve Block Project. And I'm glad to announce we've starting Ultrasound Learning Seminars and are offering nerve block and general ultrasound procedures courses for clinicians who use point-of-care ultrasound. Check us out at ulscourse.com

Femoral Nerve Block for Large Thigh Laceration

2010-11-21T15:04:00.003-05:00

Another installment on regional anesthesia in the Highland ED. Enjoy!

Distal Sciatic (Popliteal) Block for a HUGE Foot Abscess

2010-11-12T01:21:00.003-05:00

One of (hopefully) several upcoming posts where Arun Nagdev and I try to share our ultrasound-guided regional anesthesia experience at HGH. Enjoy!!!

ULS Guided Regional Anesthesia 2010

2010-10-02T12:13:00.011-04:00

So here's the audio and presenter's notes from my lecture on ULS guided regional anesthesia this year (split into parts for easier uploading/viewing). Feel free to email me (drmikestone at gmail dot com -- sorry for the spelled out version but trying to limit spam) with questions. And keep checking back on the site as we're launching a new education service for Emergency Physicians and other POC clinicians focusing on ULS guided regional anesthesia -- links will be up in the next 2-3 weeks.

PART ONE

PART TWO

Foreign Body Localization

2010-05-26T12:53:00.003-04:00

Great case illustrative of the value of point of care ultrasound for suspected foreign body. 11 year old boy who yesterday caught his pant leg in a tree branch while running around the woods in his back yard. Today complains of leg pain and mother notes a small puncture wound to the leg. Brought to the ER "to get some antibiotics". Films did not demonstrate a foreign body (as you would expect given suspicion of wooden foreign body). Video demonstrates wound appearance, radiographs, ultrasound images, and use of ultrasound to localize foreign body with needle, cut down onto foreign body and extract. All that said, check out the size of that thing!!!

Ultrasound Guided Internal Jugular Catheterization, courtesy of Arun Nagdev, MD

2010-05-17T21:24:00.002-04:00

Arun says you should use ultrasound to place IJ CVC's. Let him convince you...

Ultrasound to Assess for Pericardial Effusion, courtesy of Arun Nagdev, MD

2010-05-17T21:19:00.002-04:00

You think you know everything about pericardial effusions on ultrasound? Arun doesn't think you do...

Ultrasound and Pneumothorax, courtesy of Arun Nagdev, MD

2010-05-17T21:18:00.006-04:00

An introduction to the use of ultrasound for the identification of pneumothorax.

Intro to FAST exam, courtesy of Arun Nagdev, MD

2010-05-17T21:14:00.002-04:00

A 15 minute or so lecture on the Focused Assessment with Sonography in Trauma.

Abdominal Aortic Aneurysm, courtesy of Arun Nagdev, MD

2010-05-17T21:07:00.002-04:00

A 12 minute lecture on the use of bedside point-of-care ultrasound for the detection of AAA.

Valvular Pathology : Mitral Stenosis

2010-05-04T14:12:00.008-04:00

Was talking to a bunch of residents who were skeptical that they'd be able to pick up on valvular pathology doing a bedside echo. So here's the first of what will be a few posts on valvular heart disease for the EM and Critical Care physician.

Mitral stenosis usually results from rheumatic carditis (though there are, of course, a number of other causes) and most commonly presents decades later with atrial fibrillation (due to LAE), embolic events (due to afib), hoarseness (compression of recurrent laryngeal due to LAE), or hemoptysis (secondary to pulmonary HTN). TEE is more accurate for estimating gradients and judging severity of disease, but TTE is just fine for making the diagnosis at the point of care.

Hallmarks are left atrial enlargement, thickening and restrictive motion of the mitral valve, and atrial thrombus. On a parasternal long or apical 4 chamber view, a characteristic "elbowing" of the anterior mitral valve leaflet (AMVL) is seen as the valve apparatus opens during diastole but the leaflet's tip is tethered at the valve orifice. Clip below is apical oblique with left side of heart on right side of screen (note the elbowing of the AMVL and the biatrial enlargement in this patient with longstanding mitral stenosis):

A parasternal or subcostal short axis view will demonstrate thickening of both anterior and posterior mitral valve leaflets as seen here:

Also M-mode can demonstrate anterior motion of the posterior mitral valve leaflet during diastole as it is tethered to the AMVL.

Grading severity and estimating mitral valve area is best done using Doppler estimation of the pressure gradient between LV and LA, and while not extremely complicated is beyond the focus of this blog and will not be covered here.

Blocks Unblinded

2010-03-24T02:03:00.000-04:00

A trimmed-down, < 10 minute, youtube-compliant Quicktime version of my lecture on ultrasound guided regional anesthesia.

Head and Neck Ultrasound in the ED

2010-03-24T01:27:00.004-04:00

Am posting a Quicktime version of my upcoming lecture at AIUM 2010 in San Diego on Head and Neck sonography in the ED.

Glenohumeral Injection

2010-01-31T17:28:00.001-05:00

This is an awesome instructional video on intra-articular glenohumeral injection for reduction of shoulder dislocations done by Mikaela Chilstrom, MD -- one of the SUNY/County ultrasound fellows. Check it out and stop sedating people in the midst of our propofol shortage! Narration by Brian "The Voice" Baker, MD.

IVC and Iliac Thrombosis

2009-12-16T12:48:00.002-05:00

So this is something I think is easy to do but often not taught during education of clinicians who wish to investigate for DVT at the bedside. There is a lot of discussion and literature and controversy over the use of an abbreviated 2 point technique (the femoral vein from saphenofemoral junction to bifurcation, and popliteal vein through trifurcation) vs. a "3 point" technqiue (entire femoral and superficial femoral vein as well as the popliteal vein).

One thing that is not often talked about however is checking for phasicity in the common femoral vein as a marker of proximal venous thrombosis. The idea is that diaphragmatic movement results in changes in intra-thoracic and proximal IVC pressure and will result in increases and decreases in femoral vein flow over the course of the respiratory cycle. The absence of these changes implies that something is blocking the transmission of these pressure changes to the proximal femoral vein. If bilateral femoral veins lack phasicity, thrombus or ocmpression of the IVC is most likely. If unilateral phasicity is absent, iliac thrombosis or compression is most likely on that side.

I've checked for this hundreds of times in patients with leg swelling, but just recently saw my first case of iliac vein thrombosis (where femoral and popliteal exams were completely normal aside from the lack of phasicity). The image above demonstrates normal phasic respiratory flow (on the left side of the pulse wave Doppler tracing), and a flow response to deep breathing (on the right side of the pulse wave Doppler tracing.)

The image above demonstrates absent phasic respiratory flow in the proximal femoral vein on the ipsilateral side of the iliac vein thrombosis. Remember that absent phasicity suggests occlusion of the vein (iliac or IVC) and that this can be due to thrombus or any number of causes of external compression.

References:

Lin EP, Bhatt S, Rubens D, Dogra VS.The importance of monophasic Doppler waveforms in the common femoral vein: a retrospective study. J Ultrasound Med. 2007 Jul;26(7):885-91

Selis JE, Kadakia S. Venous Doppler sonography of the extremities: a window to pathology of the thorax, abdomen, and pelvis. AJR Am J Roentgenol. 2009 Nov;193(5):1446-51.

Willeput R, Rondeux C, De Troyer A. Breathing affects venous return from legs in humans. J Appl Physiol. 1984 Oct;57(4):971-6.

Right Heart Strain

2009-12-16T02:41:00.015-05:00

Diagnosis of right heart strain can be of great clinical utility in patients with dyspnea, tachypnea, hypoxemia and/or hemodynamic instability as it significantly reorganizes the differential diagnosis to focus on entities such as massive pulmonary embolism and cor pulmonale of any etiology. Transthoracic echocardiography can be used to identify right heart strain, and the clinician's first goal is to demonstrate an increase in right ventricular diameter. This is one of the core 3 questions clinicians should ask while evaluating the heart during clinical ultrasound examinations (is there a pericardial effusion?, what is the left ventricular function?, and is there evidence of right heart strain?). In patients in cardiac arrest or with severe hemodynamic instability, the finding of right heart strain in the appropriate clinical setting may prompt clinicians to consider the administration of tissue plasminogen activator or other thrombolytic agents.

The normal right ventricular to left ventricular ratio (in size) is 0.6:1.0 (the right ventricle is approximately two thirds the size of the left ventricle). A right ventricle equal or greater in size as compared to the left ventricle strongly suggests right heart strain. Flattening of the interventricular septum resulting in a "D-shaped" left ventricle on the parasternal short axis view occurs with right ventricular pressure overload (where the septum remains flat throughout the cardiac cycle) or right ventricular volume overload (where the septum resumes a normal shape during systole).

Of note, measurement of the velocity of triscuspid regurgitation, often associated with right ventricular pressure and/or volume overload (aka strain), can be used to estimate the degree of pulmonary hypertension present.

Also of note is McConnell's sign, where apical right ventricular systolic function is preserved in the setting of global right ventricular dyskinesis. This was felt to strongly suggest pulmonary embolism as the etiology of right heart strain, but has been called into question recently (see references).

Clinicians should remember, however, that while some features suggest chronic right heart strain (increased trabeculations, hypertrophy of free and septal walls) and some features suggest acute right heart strain (normal wall thickness), it can be difficult to determine if right heart strain is acute or chronic, and by no means does the finding of an enlarged right ventricle confirm the diagnosis of pulmonary embolism.

Thanks to Drs. Chilstrom and Secko for the McConnell's and Triscuspid Regurgitation clips. Be sure to cycle through the clips by clicking on the left or right arrows in the video player.

References:
McConnell MV, Solomon SD, Rayan ME, Come PC, Goldhaber SZ, Lee RT. Regional right ventricular dysfunction detected by echocardiography in acute pulmonary embolism. Am J Cardiol. 1996 Aug 15;78(4):469-73.

Casazza F, Bongarzoni A, Capozi A, Agostoni O. Regional right ventricular dysfunction in acute pulmonary embolism and right ventricular infarction. Eur J Echocardiogr. 2005 Jan;6(1):11-4.

Lodato JA, Ward RP, Lang RM. Echocardiographic predictors of pulmonary embolism in patients referred for helical CT. Echocardiography. 2008 Jul;25(6):584-90.

Pediatric Lung Sonography

2009-12-15T01:24:00.003-05:00

Ever been in the middle of a pediatric resuscitation and wanted to know if the endotracheal tube was in the mainstem bronchus or the trachea or the esophagus? Or if the barotrauma of positive pressure had caused a pneumothorax? There's a lot out there on diaphragm excursion vs. lung sliding vs. visualization of the endotracheal tube at the neck and it's worth checking out though there is still a need for additional research in this potentially high-yield application (see references). Video below is from a 3 day old infant with poor breath sounds after pre-hospital intubation. Notice that a linear transducer shows you more than 5 interspaces and is a great way to get a global view of the hemithorax in a neonate. In this case there are A-lines (A vs B vs C vs E vs W vs Z coming in a future post) with no visible pleural sliding on the right side of the screen (towards the patient's feet), and normal sliding on the left side of the screen (towards the patient's head) with B-lines and a small pleural effusion present (likely a result of barotrauma with subsequent atelectasis of the right lung and reactive effusion vs. small hemothorax).

Thanks to Jen Chao for setting up the ultrasound course in El Salvador this past spring where this clip was obtained.

References

Kerrey BT, Geis GL, Quinn AM, Hornung RW, Ruddy RM. A prospective comparison of diaphragmatic ultrasound and chest radiography to determine endotracheal tube position in a pediatric emergency department. Pediatrics. 2009 Jun;123(6):e1039-44. Epub 2009 May 4.

Blaivas M, Tsung JW. Point-of-care sonographic detection of left endobronchial main stem intubation and obstruction versus endotracheal intubation. J Ultrasound Med. 2008 May;27(5):785-9.

Galicinao J, Bush AJ, Godambe SA. Use of bedside ultrasonography for endotracheal tube placement in pediatric patients: a feasibility study. Pediatrics. 2007 Dec;120(6):1297-303.

Hsieh KS, Lee CL, Lin CC, Huang TC, Weng KP, Lu WH. Secondary confirmation of endotracheal tube position by ultrasound image. Crit Care Med. 2004 Sep;32(9 Suppl):S374-7.