UMEM Educational Pearls

Effort Thrombosis

Effort thrombosis, also called Paget von Schrotter disease, occurs when either the axillary and or subclavian veins thrombose. The condition is more common in young, healthy (>males) patients and presents with the usual DVT symptoms of arm pain, swelling, and pain.

The disease was originally described in patients performing vigorous activities, like weight lifting or repetitive over-the-head lifting. This type of activity has been reported to kink the subclavian vein and lead to clot formation.

Diagnosis and therapy is the same for any other type of DVT.

When patients present with acute MI, all NSAIDS should be discontinued (e.g. ibuprofen, COX-2 inhibitors, etc.) during the hospitalization. Continued use of NSAIDs during the hospitalization increases the risk of CHF, myocardial rupture, hypertension, reinfarction, and mortality.

Some of the causes of acute vision loss are:

• Cardiac Causes include:
  • Emboli -- causes can be atherosclerotic plagues, atrial fibrillation, endocarditis.
  • Arteritis
  • Dissection
• Hematologic causes
  • Hypercoaguable state
  • Hyperviscosity
  • Anemia
• Ocular Causes
  • Angle-closure glaucoma
  • Papilledema/neoplasm: Intracranial hypertension
  • Intraocular foreign bodies:
  • Central retinal artery occlusion
  • Anterior ischemic optic neuropathy
  • Ruptured globe
• Miscellaneous
  • Migraine
  • Hysteria
  • Drugs (i.e.: viagra and its counterparts)

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Ductal-Dependent Cardiac Lesions in the Neonate

• Often present in the first 1-2 weeks of life (children born prematurely tend to be at the upper end of the spectrum as they may have delayed closure of the ductus arteriosus)
• May present with tachypnea, sudden onset of cyanosis or pallor (often worse with crying), diaphoresis with feeds, lethargy, or failure to thrive
• Oxygen challenge - place baby on 100% 02 via NRB;  10% improvement in SpO2 (or 30mmHg increase in PaO2 on ABG) suggests a pulmonary issue;  no or minimal change suggests a congenital heart defect
• If congenital heart disease is suspected, start PGE-1 infusion at a rate of 0.05-0.1ug/kg/minute;  improvement may be drastic and is usually seen within 15 minutes
• Side effects of PGE-1 infusion include apnea, fever, hypotension, and seizures;  have your code cart and intubation equipment ready to go prior to beginning infusion

NEW TREATMENT in diabetes

It was discovered that glucose given ORALLY caused more insulin release than glucose administered INTRAVENOUSLY. This led to the discovery of the incretin hormones, which are secreted by the gut (INtestinal SECRETion of INsulin), GIP and GLP-1.

The incretin-based therapies increase levels of GLP-1, either by providing an incretin mimetic (exenatide and liraglutide), or by inhibiting their breakdown by DPP-4 (sitagliptin, saxagliptin, vilagliptin)

Their administration results in:

• Stimulation of glucose dependent insulin secretion
• Suppression of glucagon secretion
• Slowing of gastric emptying
• Improvement if b-cell functioning

Causing:

• Improved glycemic control
• Decrease in A1C
• Mild weight loss
• Mild decrease in BP

                 STAY TUNED FOR DOSING AND ADVERSE EVENTS!

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Optimal brain imaging for diagnosing and managing acute ischemic stroke should address the presence of 4 essential issues:

• hemorrhage
• intravascular thrombus
• core irreversibly infarcted tissue and its size, and
• hypoperfused tissue at risk for subsequent infarction if not rescued.

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Optimal brain imaging for diagnosing and managing acute ischemic stroke should address the presence of 4 essential issues:

• hemorrhage
• intravascular thrombus
• core irreversibly infarcted tissue and its size, and
• hypoperfused tissue at risk for subsequent infarction if not rescued.

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Calciphylaxis is a rare disorder caused by systemic arteriolar calcification which leads to ischemia and necrosis.  It is characterized by painful ischemic necrotic lesions on adipose tissue areas such as abdomen, buttock and thighs.  This commonly occurs in patients with ESRD on hemodialysis or after transplant, but can also occur with other patients, such as those with hyperparathyroidism.

Diagnosis is made clinically, with the help of a skin biopsy as needed.  Differential diagnosis includes cholesterol embolization, warfarin necrosis, cryoglobulinemia, cellulitis and vasculitis.  There are no specific laboratory findings, although patients may manifest elevated PTH, phosphorous, calcium or calcium x phosphorous product. 

Infection is usually the cause of the high mortality rate of this condition, which has a reported mortality of 46%, or 80% if ulceration is present.

Treatment includes local wound care, trauma avoidance, electrolyte correction, increased frequency of dialysis or parathyroidectomy as needed.  Surgical debridement is controversial; as the risk of infection may outweigh the benefit in terms of outcome. 

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The Art of Pimping-And How to Protect Against

This monday's pearl (ok, I know, it's tuesday now) comes from Michelle Lin's blog: academic life in emergency medicine. It is more gem than pearl, and it discusses what medical students and residents do to avoid being pimped. It is a must read!

Here is the link to the discussion on Michelle Lin's blog:

http://academiclifeinem.blogspot.com/2009/11/trick-of-trade-essential-skills-for.html

Just a few note worthy "pimping protection procedures":

• The "Muffin"-person being pimped raises a muffin (or some other food item) to their mouth as they are being pimped. And if the person with the muffin stills gets the question, the pimpee pretends to choke, thus avoiding future pimp questions
• The "Eclipse"-eclipsing your head with someone in front of you, that way the pimper can't see you.
• The "Politician's" approach-answering the question you wished you were asked.

Happy pimping!

Up to 10% of elderly patients in the ED meet criteria for acute delirium, though misdiagnosis rates are very common.
The most common cause of delirium in the elderly, overall, is medication effects. Other common causes are infections (UTIs most common), CNS abnormalities, cardiovascular abnormalities, electrolyte/metabolic abnormalities, and temperature abnormalities (fever or hypothermia).

Vision loss whether acute or chronic is a common presenting complaint to the ED.  This will be the first in a series of pearls on the subject.  This pearl will address the nomenclature used by ophthalmology based on the length of vision loss.

    •    Transient visual obscuration - Episodes lasting seconds. Usually associated with papilledema and increased intracranial pressure.
    •    Amaurosis fugax - Brief, fleeting attack of monocular partial or total blindness that lasts seconds to minutes
    •    Transient monocular visual loss  or transient monocular blindness - A more persistent vision loss that lasts minutes or longer
    •    Transient bilateral visual loss - Episodes affecting one or both eyes or both cerebral hemispheres and causing visual loss
    •    Ocular infarction - Persistent ischemic damage to the eye, resulting in permanent vision loss

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• Neuroleptic Malignant Syndrome (NMS) is a rare, but true neurological emergency which is today associated with much lower mortality given heightened awareness about the condition.

• It typically initially begins with muscle rigidity resulting in rhabdomyolysis, followed by high fever, and delirium.

• Always check creatinine phosphokinase (CPK) and white blood cell levels when concerned about NMS, as these typically elevate in response to muscle breakdown.

• The following mnemonic (FEVER) serves as a reminder of the signs and symptoms associated with NMS:

           F - Fever (anything over 100.4 F counts)

            E - Encephalopathy

           V - Vital signs instability

           E - Enzymes elevation (i.e. CPK)

            R - Rigidity of muscles

Spinal Epidural Abscess Pitfalls

• The classic triad of back pain, fever, and neurologic deficits are found in < 15% of patients at the time of presentation
• Up to 75% will be afebrile
• Up to 67% will have a normal initial neurologic exam
• < 40% have a WBC greater than 12,000 cells/mm³
• < 33% will have an abnormality on plain film in the first 7-10 days

Take Home Point: In the patient with risk factors for spinal epidural abscess (IVDU, DM, indwelling catheters, etc) do not exclude the diagnosis based upon the absence of a fever, a normal WBC count, and a normal neurologic exam.

Ring-removal is a dreaded problem in pediatric hand and finger injuries.  Removal can be difficult and time consuming.  The relatively recent introduction of Tungsten into the jewelry market has further complicated this problem:

• The hardest metal used in jewelry - cannot be scratched, much less cut, by common tools
• Cheap, easy to buy online, attractive to adolescents

However, it is:

• Extremely brittle
• May be safely and quickly broken with locking pliers (also cheap), by sequentially, gradually tightening the locking plier grip

This video explains how.  Of course, this works on adults as well.

http://www.youtube.com/watch?v=poM423pewRE

_{I have no relationship with the copany which made this video - it was simply chosen for its clear explanation of the solution described in this pearl.}

 Myocardial infarctions involving the left circumflex artery are often associated with ECGs that lack any ST-segment changes (38% in one representative study). Oftentimes when there are ST-changes, there may simply be anterior lead ST-segment depression. In these patients, acquisition of a few posterior leads frequently demonstrates STEMI. Some data does exist that failure to diagnose these posterior STEMIs (e.g. simply diagnosing anterior "ischemia" rather than posterior "STEMI") results in increased mortality.

So what's the bottom line?
1. In patients with isolated anterior lead ST-segment depression, always check for posterior STEMI with a couple of posterior leads.
2. In patients with non-significant ECGs but concerning persistent symptoms, always check for posterior STEMI with a couple of posterior leads.

This is always a great time to use that 80-lead ECG if your ED has one.

Amal

MEWDS (Multiple Evanescent White Dot Syndrome)

• A rare, unilateral, self-limiting inflammatory disease
• Afflicts young women more than men in a 4:1 ratio.
• Patients typically present complaining of
  • Sudden, painless, monocular decline in central acuity
  • Photopsias-- def. appearance as of sparks or flashes in retinal irritation
  • Dyschromatopsia-- def> disorder of color vision
  • Central/paracentral scotomas
• Visual acuity usually in the  20/40-20/400
• Fluorescein angiography of active lesions typically demonstrate a "wreath-like" hyperfluorescence of the white dots
• Disease is usually self limited (resolves in weeks to months) with an excellent prognosis.
• There are no known treatment options.

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Global symptoms of elevated intracranial pressure (ICP) include:

• Headache (likely mediated via the pain fibers of cranial nerve V in the dura and blood vessels)
• Depressed consciousness (likely due to either the local effect of mass lesions or pressure on the midbrain reticular formation)
• Vomiting

There is no prospective, randomized study to elucidate propofol’s effect on the critically ill patient. By definition, Propofol Infusion Syndrome (PRIS) has the following characteristics:

• acute bradycardia progressing to asystole
• lipemic plasma
• fatty liver enlargement
• metabolic acidosis with negative base excess > 10
• rhabdomyolysis or myoglobinuria

It has been thought that PRIS was limited to patients with prolonged use, but we now know that this is not necessarily true.

It has been shown that PRIS is more likely with the following risk factors:

• <19 years old
• male
• received a vasopressor
• cardiac manifestations (including Brugada Syndrome)
• metabolic acidosis
• renal failure
• hypotension
• rhabdomyolysis
• dyslipidemia

The treatment for suspected PRIS is:

• Stop infusion
• Hemodynamic stabilization
• Carbohydrate substitution
• Hemodialysis or hemofiltration
• ECMO as necessary

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Well, this monday's pearl is a bit different than prior pearls. I wanted to let you know about a very cool website I came across recently called Clinical Reader. There is a whole lot in the recent medical education literature that discusses "Web 2.0." Web 2.0 involves learning through interactive websites, blogs, podcasts, etc. Medical education is really starting to head out of the classroom, and I wanted to mention a newer website that a lot of folks are talking about. 

Clinical Reader is a new medical RSS aggregator. What, you might ask, does this mean?

An RSS aggregator is a site that puts together information for you, that's right, for you. It actually does the work for you. Did I mention that it does the work for you? On this site, for example, if you are interested in "Emergency Medicine," the site finds all (or almost all) EM journals and brings you all of the latest information and updated articles. If you are into "Medical Education," you simply choose that category from a drop down menu and poof, you have all of the latest publications/reviews from the major medical education journals. Just choose your category and/or specialty and you are off and running. 

Try it out. It isn't 100% perfect, but it is very cool.

http://clinicalreader.com/

During this season of the ever-present viral respiratory illness, we must be on the lookout for the potentially-deadly -entity of myocarditis. A recent study suggests some clues to when the diagnosis should more strongly be considered in patients presenting with viral respiratory symptoms.

1. Most cases of myocarditis were not initially recognized by primary care MDs or emergency health care providers. 84% of patients needed more than one visit within 2 weeks before the diagnosis was made. This highlights the difficulty in Dx and frequent misdiagnosis rate.
2. The most common presenting symptom was dyspnea (69%) and most common sign was tachypnea (60%).
3. Although resting tachycardia is often taught as a common finding, 66% of patients had a normal HR.
4. The most helpful findings in terms of helping distinguish myocarditis from benign common viral URIs was hepatomegaly (present in 50%) and cardiomegaly (present in 60%).
5. An abnormal ECG was present in 100% of cases. The most common abnormalities were tachycardia, ventricular hypertrophy, and ST or T wave changes.
6. 54% of patients had elevated troponin levels.

So what's the bottom line?
1. If your patient has tachypnea or dyspnea, strongly consider getting a CXR. In that case, look carefully for cardiomegaly.
2. Always assess for and document the presence or absence of hepatomegaly.
3. A completely normal ECG is strong evidence against myocarditis.

[Durani Y, Egan M, Baffa J, et al. Pediatric myocarditis: presenting clinical characteristics. Am J Emerg Med 2009;27:942-947.]