UMEM Educational Pearls

General Information:

-As of April 5^th, 14 confirmed cases of a new influenza A virus (H7N9) have occurred in China.  Six of those have died. 

-Presumed transmission via infected poultry in bird markets, and thus far no person-to-person transmission has occurred.

-Likely susceptible to oseltamavir or inhaled zanamivir

Area of the world affected:

-China

Relevance to the US physician:

- Suspect in patients with a respiratory illness and appropriate travel history.

- Refer to CDC within 24 hours if test positive for flu A but cannot be subtyped

- If H7N9 is suspected, patients should be under droplet and airborne precautions

Bottom Line:

No human-to-human transmission from H7N9 thus far, but the possibility exists.  Any unsubtypeable influenza A patient should be placed on droplet and airborne precautions and oseltamavir or zanamivir started immediately.

University of Maryland Section of Global Emergency Health
Author: Andi Tenner, MD, MPH

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Methods: A large retrospective case series evaluated 121 children under 6 years old with hypoglycemia from a sulfonylurea ingestion.

Results:

• In addition to dextrose, patients who received octreotide had a median of zero hypoglycemic episodes after octreotide (compared to 2 before treatment, p < 0.0001).
• Median blood glucose concentrations after receiving octreotide were also higher (62 mg/dL vs 44, p < 0.001).
• Most required only 1 dose of octreotide with no reported adverse effects.

Authors' Conclusion: Octreotide administration decreases the number of hypoglycemic events and increases blood glucose concentrations in children with sulfonylurea ingestion.

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Question

64 year-old female presents with chest pain following an argument with her husband. Her echocardiogram (apical four-chamber view) and ECG are shown. Her initial troponin is 10. What's the diagnosis?

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• Takayasu arteritis (TA) is a granulomatous vasculitis that affects the aorta and its major branches
• Involvement of the aortic arch is associated w/CNS symptoms, claudication, absent peripheral pulses, and cardiac manifestations
• The EULAR/PReS consensus criteria for Dx of childhood TA requires characteristic angiographic abnormalities of the aorta plus 1 of the following:

1. Absent peripheral pulses or claudication
2. Blood pressure discrepancy in any limb
3. Bruits
4. Hypertension
5. Elevated acute phase reactants

• Gold standard for Dx is angiography; however, CT and MR angiograms are less invasive and can detect inflammation & luminal diameter changes 
• Tx is challenging, steroids may induce remission in up to 60%

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Recent advances in resuscitation science have enabled emergency physicians to identify factors associated with good neurologic and survival outcomes. Cases of persistent ventricular dysrhythmia (VF or VT) present a particular challenge to the critical care provider. The evidence base for interventions in shock refractory ventricular VF mainly consists of case reports and retrospective trials, but such interventions may be worth considering in these difficult resuscitation situations:

1. Double sequential defibrillation
-For shock-refractory VF, 2 sets of pads are placed (anterior/posterior and on the anterior chest wall). Shocks are delivered as "closely as possible."^1,2

2. Sympathetic blockade in prolonged VF arrest
-"Eletrical storm," or incessant v-fib, can complicate some arrests in the setting of VF. An esmolol bolus and infusion may be associated with improved survival.³  Left stellate ganglion blockade has been identified as a potential treatment for medication resistant VF.⁴

3. Don't forget about magnesium! 
-May terminate VF due to a prolonged QT interval 

4. Invasive strategies
-Though resource intensive, there is limited experience with intra-arrest PCI and extracorporeal membrane oxygenation. Preestablished protocols are key to selecting patients who may benefit from intra-arrest PCI and/or ECMO. ⁵

5. Utilization of mechanical CPR devices 
-Though mechanical CPR devices were not officially endorsed by the AHA/ECC 2010 guidelines, there's little question that mechanical compression devices address the complication of provider fatigue during ongoing resuscitation. 

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A new recommendation in the 2013 Ischemic Stroke Guidelines provides guidance on what to do in patients taking new oral anticoagulants who are deemed eligible for IV fibrinolysis. Here is what the guidelines say:

• The most helpful lab tests are not widely available.
• A detailed history is important, but not always obtainable.

Until further data are available, a history consistent with recent use of new oral anticoagulants generally precludes use of IV tPA.

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Children frequently present with "pink eye" to the ED.  When they do, parents often expect antibiotics.  How many of these kids actually need them?  Previous studies have shown approximately 54% of acute conjunctivitis was bacterial, but antibiotics were prescribed in 80-95% of cases.

A prospective study in a suburban children's hospital published in 2007, showed that 87% of the cases during the study period were bacterial.  The most common type of bacteria was nontypeable H. influenza followed by S. pneumoniae.

Topical antibiotic treatment has been shown to improve remission rates by 6-10 days.

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• Although Keppra has been used more frequently in clinical practice, there is little evidence for its use in status epilepticus.
• It has a wide spectrum of action and few drug interactions.
• Initially, case series appeared to be highly successful in terminating seizures as an add-on agent.
• A review of 2 prospective studies found efficacies of 44% as an add- on agent, and 75% as a primary agent. The studies had markedly different populations.
• In a retrospective study, the treatment failure rates were 3X higher than that of intravenous valproic acid as an add-on agent in terminating status epilepticus.
• Therefore, although it is used frequently, the evidence for use is limited and inconclusive in terminating status epilepticus.

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Spring is in the air... and so is rotavirus. 

Area of the world affected:

·       Diarrheal illnesses were responsible for 1.6 million deaths for children under 5 globally in 2002. 

·       This number has improved over the years, in part due to oral rehydration salts (ORS) which were developed for cholera. 

Relevance to the US physician:

http://www.cdc.gov/surveillance/nrevss/rotavirus/region.html#top

·       ORS are also important for rotavirus treatment and uncomplicated gastroenteritis in children and adults. 

·       Commercially prepared solutions have different concentrations of ingredients, but all will work as better treatment and rehydration than common household products like sports drinks and juice. 

Bottom line:

Consider ORS in patients with uncomplicated acute gastroenteritis.

University of Maryland Section of Global Emergency Health

Author: Jennifer Reifel Saltzberg, MD, MPH

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Hormonal Dysfunction in Neurologic Injury

• In the critically ill patient with neurologic injury (SAH, TBI), the initial treatment focus is to maintain adequate cerebral perfusion pressure, control intracranial pressure, and limit secondary injury.
• Once stabilized, however, it is important to consider endocrine dysfunction in the brain injured patient.
• Endocrine dysfunction is common in neurologic injury and may lead to increased morbidity and mortality.  In fact, over half of SAH patients develop acute dysfunction of the HPA, resulting in low growth hormone, ACTH, and TSH. 
• In addition to hormonal dysfunction, sodium abnormalities (i.e. hyponatremia) are present in up to 80% of critically ill SAH patients.
• Consider hormonal replacement therapy (or hypertonic saline in cases of severe hyponatremia) for patients with evidence of endocrine dysfunction.  For some, this therapy can be life-saving.

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Question

What's the Diagnosis?

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• Identifying ST-segment changes in patients with LVH is frequently associated with false-positive diagnoses of acute coronary syndrome
• This study analyzed the ACTIVATE-SF database, a registry of consecutive emergency department STEMI diagnoses from 2 medical centers (411 patients)
• In patients with anterior territory ST-elevation, using a ratio of ST segment to R-S–wave magnitude >25% as a diagnostic criteria for STEMI significantly improved specificity for an angiographic culprit lesion (true positive) 
• Although this rule requires further study in a larger population it may augment current criteria for determining which patients with ECG LVH should undergo PCI

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Knee Pain Injuries are Radiographs needed?

Many people know that the folks in Ottawa have come up with a rule to determine whether radiographs are needed in patients complaining of knee pain.  The Ottawa Knee rules that that radiographs are only required for knee injuries with any of the following:
    •    Age 55 years or older
    •    isolated tenderness of patella
    •    tenderness at head of fibula
    •    inability to flex to 90'
    •    inability to bear weight both immediately and in the emergency department (4 steps)

Well another group in Pittsburgh have their own set of rules that were recently shown to be more specific with equal sensitivity.  The Pittsburgh decision rules state that radiographs are only needed if

• There is a history of fall or blunt trauma AND  ( Patient is < 12 or > 50 years old OR Patient is unable to walk for weight bearing steps in the ED. )

So consider using the Pittsburgh or Ottawa Knee rules the next time you have a patient with knee pain to determine if those radiographs are really needed.

The full article can be found at http://www.ajemjournal.com/article/S0735-6757%2812%2900566-9/abstract

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You have diagnosed an infant or child with pneumonia.  How do you decide if they need admission?

The Pediatric Infectious Disease Society and the British Thoracic Society each have guidelines from 2011 to help with this decision.

Background Information:

Combination antiretroviral therapy (cART) reduces HIV-associated morbidities and mortalities but cannot cure infection. Recent literature has suggested that early initiation of cART with primary infection  can lead to “functional cure” for HIV infected patients with suppressed viremia and delayed progression to clinical symptoms.

Pertinent Study Design and Conclusions:

- Researchers studied 14 patients whose treatment with combination antiretrovirals began soon after exposure to HIV. The patients' viral loads became undetectable within roughly 3 months, and treatment was interrupted after about 3 years.

- The patients were found to have very low viral loads and stable CD4-cell counts after several years without therapy. The researchers estimate that about 15% of those treated early could achieve similar results.

Bottom Line:

Have a high suspicion of acute anti-retroviral syndrome in the ED (fever, rash, pharyngitis, lymphadenopathy) and test properly (viral load NOT ELISA) to identify patients who may benefit from early, rapid initiation of cART.

University of Maryland Section of Global Emergency Health

Author: Emilie J. B. Calvello, MD, MPH

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There are several reasons why a mechanically ventilated patient may decompensate post-intubation. Immediate action is often needed to reverse the problem, but it can be difficult to remember where to start as the vent alarm is sounding and the patient is decompensating.

Consider using the mnemonic “D.O.P.E.S. like D.O.T.T.S.” to assist you in first diagnosing the problem (D.O.P.E.S.) and then fixing the problem (D.O.T.T.S.). You can view an entire lecture on the Crashing Ventilated Patient here.

Step 1: Could this decompensation be secondary to D.O.P.E.S.?

• Displaced ET tube / ET tube cuff not inflated or has a leak
• Obstruction of ET tube
• Pneumothorax
• Equipment malfunction (disconnection of the ventilator, incorrect vent settings, etc.)
• Stacking (breath stacking / Auto- PEEP; click here for a review)

Step 2: Fix the problem with D.O.T.T.S.

• Disconnect – Disconnect patient from the ventilator
• Oxygen – Oxygenate patient with a BVM and feel for resistance as you bag
• Tube position / function – Did the ET tube migrate? Is it kinked or is there a mucus plug?
• Tweak the vent – Are the settings correct for this patient?
• Sonogram (ultrasound) – Sonogram to look for pneumothorax, mainstem intubation, etc. 

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Question

35 year-old male presents after a motor vehicle crash. No blood seen at the meatus of the penis and a Foley catheter is placed (see photo below). What's the next diagnostic step?

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In children, it is important to consider the maximum doses of local anesthetics when performing a laceration repair or painful procedure like abscess drainage. If there are multiple lacerations, or large lacerations, it may be possible to exceed those doses if one is not careful.

Max doses of common anesthetics

• Lidocaine WITHOUT epinephrine – 4 mg/kg (0.4 mL/kg of 1% lidocaine)
• Lidocaine WITH epinephrine – 7 mg/kg (0.7 mL/kg of 1% lidocaine)  
• Bupivicaine WITHOUT epinephrine – 2 mg/kg (0.8 mL/kg of 0.25% bupivicaine)
• Bupivicaine WITH epinephrine – 3 mg/kg (1.2 mL/kg of 0.25% bupivicaine)

For example, in a 20 kg child (an average 5-6 year old), the maximum doses would be:

• Lidocaine 1% - 8 ml
• Lidocaine 1% with epi – 14 ml
• Lidocaine 2% - 4 ml
• Bupivicaine 0.25% - 16 ml
• Bupivicaine 0.25% with epi - 24 ml

Pearls:

• For added safety, some advocate not exceeding 80% of the max dose in children < 8 years of age
• Higher concentration of lidocaine beyond 1% does not improve the time of onset or duration of action and may increases the risk of toxicity
• The addition of epinephrine increases the maximum dose and duration of action, but may be more painful during infiltration
• If the repair requires large amount of local anesthetic, consider doing an regional block

Cocaine toxicity is characterized by the sympathomimetic toxidrome: tachycardia, hypertension, hyperpyrexia, diaphoresis as well as sodium channel blocking effects that can cause local anesthesia topically, QRS widening and even seizure.

Usual treatment for a cocaine toxic patient is benzodiazepines and cooling. Be wary of end organ damage, trauma and seizures.

There was a recent study that looked at dexmedetomidine to treat the sympathomimetic effects. Placebo-controlled trial used cocaine-addicted volunteer and applied intranasal cocaine. Measuring skin sympathetic nerve activity and skin vascular resistance, this study, unfortunately, showed as the dose increased  MAP did not fall further and increased paradoxically in 4 of 12 subjects.

This highlights the incredible physiologic mechanism of catecholamine release from the CNS with cocaine. This mechanism overlaps some with the centrally acting alpha agonist - dexmedetomidine and was shown in the study by Kontak et al. 

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