UMEM Educational Pearls

In the setting of an ACS, the minimum dose of ASA that should be given is 162 mg. Chewing provides antiplatelet effects slightly faster than simply swallowing, though the difference is probably not clinically significant. Enteric coated aspirin, however, clearly takes longer to work and should therefore be avoided in patients with ACS.

A dose of 325 mg does not appear to provide any further benefit beyond the 162 mg dose, though there might be a slightly higher bleeding rate. Despite that the 2005 PCI guidelines recommend a dose of 325 mg as the initial dose for patients with ACS if they are not chronically taking ASA. Otherwise, 162 mg is sufficient.

Some quick facts about Knee Injuries:

• The most common cause of acute traumatic hemarthrosis of the knee is an anterior cruciate ligament tear.
  • Most patients with an ACL injury will give a history of immediate pain, disability, knee swelling and audible pop.
• The most common ligament injuried in the knee is the medial collateral ligament.
• Patella dislocations
  • Usually lateral dislocations and often spontaneous reduce.
  • Hyperextend the knee to make the reduction easier.
• Dislocation of the knee:
  • Anterior is the most common and usually secondary to hyperextension
  • Popliteal artery injury is commonly seen and must be looked for.  Easy bedside test is Ankle Brachial Indexs.

Bronchiolitis: Use of RSV rapid testing

• Firstly, know that the sensitivity of the test is ~60% (leaving 40% that have the disease testing falsely negative)
• Secondly, in whom will the result impact your decision?
  • High-risk patient populations (at risk of decompensation or apnea)
    • Premature (especially <34 wks GA)
    • Infants < 2months of age
    • Chronic Lung Disease
    • Congenital Heart Disease
  • Infants undergoing sepsis evaluations
    • The incidence of concominant serious bacterial infection and RSV is low (<1%)
       

Purcell K, Fergie J. Concominant serious bacterial infections in 2396 infans and children hospitalized with respiratory syncytial virus lower respiratory tract infections. Arch pediatr adolesce med. 2002; 156: 322-324.

Levetiracetam

• A new anticonvulsant that is 100% renally eliminated
• Does not require therapeutic drug monitoring like phenytoin
• The IV form does not cause skin necrosis or have cardiotoxicity like phenytoin
• Is being investigated in benzodiazepine-refracory status epilepticus (1)
• Fairly safe drug even in overdose (Barrueto et al ;) )

Knake et al. Intravenous levetriacetam in thetreatment of benzodiazepine-refractory status epilepticus. J Neurol Neurosurg Psychiatry 2007 Sept 26; Epub

• Consider cervical artery dissection as the source of stroke in patients younger than age 40.
• About 20% of such strokes are due to carotid artery or vertebral artery dissections.
• Of these, internal carotid artery dissections are the most common.
• These patients often present with a triad of neck and head pain, Horner's syndrome, and pulsatile tinnitus.
• MRI/MRA is the best non-invasive diagnostic modality for arterial dissection.  Angiography may needed for confirmation.

Selim M, Caplan LR. Carotid Artery Dissection.  Current Treatment Options Cardiovascular Medicine.  2004; 6:  249-253.

Stapf C, Elkind MS, Mohr JP.  Carotid Artery Dissection.  Annual Review Medicine.  2000; 51:  329-47.

Schievink W. Spontatneous Dissection of the Carotid and Vertebral arteries.  NEJM.  2001; 344:  898-906.

Adrenal Insufficiency in the Critically Ill

• Adrenal insufficiency (AI) is estimated to occur in up to 30% of critically ill patients
• The most common causes of AI in the critically ill are SIRS and sepsis
• In most cases of critically ill patients, AI is functional (i.e relative) - the adrenal response is insufficient to respond to the degree of stress
• Diagnostic clues include hyponatremia, hyperkalemia, hypoglycemia (rare), and hemodynamic instability despite IVFs and vasopressors
• Although still controversial, most feel that AI is present in critically ill patients with either a basal cortisol < 15 mcg/dl, an increase in < 9 mcg/dl after ACTH stimulation, or a random cortisol < 25 mcg/dl
• IV hydrocortisone, methylprednisolone, and dexamethasone are the 3 glucocorticoids most commonly administered
• Hydrocortisone is usually the preferred agent because it is the synthetic equivalent of cortisol (and has both glucocorticoid and mineralocorticoid activity)

Thrombolytic infusion for occluded central venous catheters

For patients with long-term indwelling central venous catheters (dialysis catheters, Hickmans, etc) who develop catheter occlusion, consider infusion of thrombolytic therapy for catheter salvage.

How do you do it, you ask?

• Infuse 2 mg of tPA through the affected port
• Can also use Urokinase if this is all you have

This treatment is very safe and is well tolerated.

Journal of Vascular Access, 2006

Adenosine should be used with great caution in patients with wide complex tachycardia for two major reasons:
1. Adenosine should never be used as  diagnostic maneuver to decide whether someone has ventricular tachycardia vs. SVT. Adenosine is well-reported to convert certain types of VT.
2. If the WCT is irregular, this may be atrial fibrillation with WPW, in which case adenosine is well-known to produce ventricular fibrillation.

Fraud (PATH audits)    (PATH = physicians at teaching hospitals)

• As a general rule, faculty may not bill Medicare for the work of residents.
• Faculty may bill for their own work, and may repeat a resident examination if necessary.
• To appropriately bill under PATH audit guidelines, faculty may make reference to a resident’s history, may simply document the variance between their exam and the resident’s exam, and should document medical decision making.
• Faculty may bill for a procedure if:
  • faculty performs the procedure
  • faculty was present for the entire procedure
  • faculty was present for the key portion of the procedure
  • faculty actively assisted the resident in performance of the procedure.

So for the residents, a lot of attendings will want to be present when you do a procedure, not because they think you will need their assistance, but because, procedures are a large revenue stream that can be lost if the attending is not present.

Thanks to Larry Weiss, MD, JD

Disclaimer: This information does not constitute legal advice, is general in nature, and because individual circumstances differ it should not be interpreted as legal advice.The speaker provides this information only for Continuing Medical Education purposes.

Pediatric Leukemia/Lymphoma Presentation in the ED

• Pts most commonly present with c/o pallor or decreased activity
• Physical Exam commonly demonstrates pallor, splenomegaly, fever, hepatomegaly, lymphadenopathy, and ecchymoses/petechiae.
• CBC’s and peripheral smears are realiably abnormal
• Patients with solid tumor more commonly present with symptoms related to tumor location (ie Abd pain, Headache, etc.)

Jaffe D, Fleisher G, Grosflam J. Detection of cancer in the pediatric emergency department. Pediatr Emerg Care. 1985 Mar;1(1):11-5.

                                      Phenytoin po      Phenytoin IV       Fosphenytoin

Time to therapeutic       6.4 hrs                  1.7 hrs                 1.3 hrs

Adverse Events              0.69/pt                   1.86/pt                 1.87/pt

Also to take into account  is that the adverse events with IV phenytoin include soft-tissue necrosis if there is extravasation of infusion. The cardiotoxicity seen with phenytoin and fosphenytoin is largely due to the propylene glycol diluent and thus not seen with oral loading or even in oral overdosing.

You decide, at least you have the data to properly evaluate the risk:benefit ratio.

• Less than 10% of sarcoidosis cases affect only the nervous system.
• In such cases, granulomas form within nervous tissue and usually only occurs when there is significant systemic involvement.
• Most sarcoid exacerbations affecting the nervous system are not recurrent. 
• Manifestations of neurosarcoidosis include:
  • 1)  Mononeuropathy - Cranial nerve dysfunction most common     (Heerfordt  syndrome = uveitis, fever, parotid gland inflammation, and facial nerve palsy).
  • 2)  Peripheral neuropathy - Sensation and/or motor dyusfunction
  • 3)  Central Nervous System -  Hypothalamus/pituitary gland, cerebral cortex, cerebellum, spinal cord (rare)

The PERC Rules revisted

How can I rule out PE without ANY testing, you ask? Do I have to get a d-dimer on that low risk patient?

Do these things keep you up at night like they do me?

Consider using the PERC rule (Pulmonary Embolism Rule Out Criteria)

This set of rules was mentioned in an earlier pearl, but there are now 3 large studies (and one on the way) that validate the use of these rules.

So, if you have a patient who is LOW risk for PE but you would like to document something in the chart that proves you thought about the diagnosis and clinically ruled it out:

If the patient is LOW risk for PE by your clinical gestalt and if the answer to ALL of the following questions is YES, then the patient is considered PERC negative:

• Age < 50 years
• Pulse < 100 bpm
• SpO2 > 95%
• No unilateral leg swelling
• No hemoptysis
• No recent trauma or surgery
• No prior PE or DVT
• No hormone use

PERC negative + Low Risk clinical gestalt = PE ruled out

Caution!

• Most people are comfortable with: LOW risk + negative d-dimer = PE ruled out but use of the PERC rules has not gained wide acceptance yet. Experts in this area predict this will change.
• Clinical gestalt must be used and the patient must be LOW risk for PE
• The PERC rule is not intended for use in moderate risk patients or in patients without an alternative diagnosis.
• The rule is really only intended to avoid testing in the patient you were really not thinking about PE in the first place. Some experts agree that writing "PERC negative" in the chart is defensible.

Jeff Kline, PERC rule. Journal of Thrombosis and Hemostasis. 2007/2008

Here's a pearl for everyone that is "enjoying" the holidays with friends...friends named Jack Daniels, Remy Martin, and Louis XIII, among others.

It's fairly well-known that light-moderate alcohol intake is associated with reductions in cardiovascular death and nonfatal MI and also a reduction in the development of heart failure. In case you've ever wondered exactly what a "drink" is and what "moderate" intake are, here are some definitions:
a. In the U.S., a standard alcohol "drink" is 1.5 oz or a "shot" of 80-proof spirits or liquor, 5 oz of wine, or 12 oz of beer.
b. "Moderate" drinking is no more than 1 drink per day for women and 2 per day for men.
c. "Binge" drinking is > 4 drinks on a single occasion for men or > 3 for women within 2 hours.

Although some studies suggest that wine (esp. red) has an advantage over other types of alcohol, other studies (including ones we've reviewed in the cardiology update series) indicate that the type of alcohol doesn't matter. Good news for many of our patients!

Child with a Limp

• First classify the limp:
  • Antalgic gait = shortened stance phase of the affected extremity due to PAIN
  • Trendeleburg gait = equal stance phase between involved and uninvolved side, shifted center of gravity; NOT Painful
• Etiologies
  • Painful Limp
    • 1-3 years of age: Septic Joint, Occult Trauma, Neoplasm
    • 4-10 years of age: Septic Joint, Transient Synovitis, Legg-Calve-Perthes Disease, Trauma, neoplasm, Rheumatologic D/O
    • 11 + years of age: SCFE, Rheumatologic D/O, Trauma, (consider AVN in pts with sickle cell disease)
  • Trendelenburg Gait
    • Indicative of underlying hip instability or muscle weakness
    • Think of congential hip dislocation and Neuromuscular Diseases/Disorders

Grossman, Emblad, Plantz. Orthopedic Emergencies in Pediatric Emergency Medicine Board Review.  2nd Edition. 2006. p305.

Ketorolac: an NSAID that gained popularity since it is not an opioid, has excellent anti-inflammatory/analgesic effects and is given IM or IV. Also has been used in renal colic secondary to smooth muscle relaxation (Prostaglandin mediated) in the ureters. You should know:

• When given IV or IM still causes PUD and has caused GI perforations.
• Renal Insufficiency is larger concern with this NSAID than others.
• Consider misoprostol for GI complications.
• Use for acute pain, limit the number doses given and don't prescribe for more than 3 days. I generally don't prescribe it at all, use another NSAID for outpatient treatment.

Corelli et al. Renal Insufficiency and ketorolac. Ann Pharmacother. 1993; 27(9): 1055-7

• Note that the use of steroids within 8 hours of injury for SCI is not routinely practiced worldwide and was initially based on a controversial study, the National Acute Spinal Cord Injury Study (NASCIS I & II).

• The approved methylprednisolone dose is 30 mg/kg IV bolus over 15 min, followed by 5.4 mg/kg/h over 23 h; begin IV infusion 45 min after conclusion of bolus.
  

Bracken MB, Shepard MJ, Collins WF, et al: A randomized, controlled trial of
methylprednisolone or naloxone in the treatment of acute spinal-cord injury.
Results of the Second National Acute Spinal Cord Injury Study. N Engl J Med
1990 May 17; 322(20): 1405-11. 

Critical Care Monitoring - End-Tidal CO₂

• End-tidal CO₂ (ETCO₂) monitoring is used to verify ETT placement, monitor procedural sedation, traumatic brain injury, and to estimate prognosis during cardiopulmonary resuscitation
• ETCO₂ concentration typically underestimates P_aCO₂ by 4-5 mmHg in healthy non-intubated patients
• This relationship is less reliable in critically ill patients secondary to shunt, altered alveolar dead space, and inadequate ventilation
• While a low ETCO₂ value is less useful in the critically ill, a high value almost always correlates with an equal or higher P_aCO₂ value
• This can be useful when monitoring conditions such as status asthmaticus, CHF, or increased ICPs in which a high ETCO₂ may signal the need for additional aggressive treatment

Secondary Causes of Hypertension

Although not that common, consider the following (with accompanying history and/or physical examination findings) in patients with hypertension:

• Renovascular hypertension (renal artery stenosis)-abdominal bruits, older patients
• Pheochromocytoma-episodic flushing, htn, headache, new onset htn in younger patient
• Cushing's disease-abdominal striae (not very specific in Baltimore), new onset hyperglycemia, classic electrolyte abnormality: hypokalemic metabolic alkalosis
• Primary Aldosteronism-new onset htn and hypokalemia
• Hyperparathyroidism-htn and hypercalcemia
• Aortic coarctation-younger patients (even young adulthood), unequal upper and lower extremity blood pressures
• Sleep apnea-typically obese patients (but not necessarily), excessive snoring, day time sleepiness (again, not specific)
• Thyroid disease (hypo or hyper)-signs and symptoms of thyroid disease

Although most of the time the patient will end up having essential hypertension, these entities should at the very least be considered.

Journal of Hypertension 2007