UMEM Educational Pearls

Category: International EM

Title: What is Quarantine and Isolation?

Keywords: Infectious diseases, isolation, quarantine (PubMed Search)

Posted: 10/16/2014 by Jon Mark Hirshon, PhD, MPH, MD
Click here to contact Jon Mark Hirshon, PhD, MPH, MD

With all the current concern about Ebola, it is important to understand what are quarantine and isolation and who can order these.

Per the Centers for Disease Control:

  • Quarantine: separates and restricts the movement of people who were exposed to a contagious disease to see if they become sick.
  • Isolation: separates sick people with a contagious disease from people who are not sick

Federal Law allows for quarantine and isolation:

  • From the Commerce Clause of the U.S. Constitution
  • Delegated to the Centers for Disease Control (CDC) by the U.S. Secretary of Health and Human Services
    • The CDC is "authorized to detain, medically examine, and release persons arriving into the United States and traveling between states who are suspected of carrying these communicable diseases."
  • The CDC may issue a federal isolation or quarantine order
    • Last large scale use was during the influenza pandemic of 1918-1919
  • Breaking of a federal quarantine order is punishable by fines and imprisonment

State laws allows for the enforcement of isolation and quarantine within their borders.

Bottom Line:

  • There have been no large-scale quarantine or isolation orders for 100 years. However, the CDC can issue an order that has the authority of the Constitution and federal law for enforcement.

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Category: Toxicology

Title: Valproic acid toxicity

Keywords: valproic acid (PubMed Search)

Posted: 10/16/2014 by Hong Kim, MD (Updated: 9/20/2024)
Click here to contact Hong Kim, MD

Valproic acid (VPA) is often used to treat seizure disorder and mania as a mood stabilizer. The mechanism of action involves enhancing GABA effect by preventing its degradation and slows the recovery from inactivation of neuronal Na+ channels (blockade effect).

 

VPA normally undergoes beta-oxidation (same as fatty acid metabolism) in the liver mitochondria, where VPA is transported into the mitochondria by carnitine shuttle pathway.

 

In setting of an overdose, carnitine is depleted and VPA undergoes omega-oxidation in the cytosol, resulting in a toxic metabolite.

 

Elevation NH3 occurs as the toxic metabolite inhibits the carbomyl phosphate synthase I, preventing the incorporation of NH3 into the urea cycle.

 

Signs and symptoms of acute toxicity include:

  • GI: nausea/vomiting, hepatitis
  • CNS: sedation, respiratory depression, ataxia, seizure and coma/encephalopathy (with serum concentration VPA: > 500 mg/mL)

 

Laboratory abnormalities

  • Serum VPA level: signs of symptoms of toxicity does not correlate well with serum level.
  • NH3: elevated
  • Liver function test: elevated AST/ALT
  • Basic metabolic panel: hypernatremia, metabolic acidosis
  • Complete blood count: pancytopenia

 

Treatment: L-carnitine

  • Indication: hyperammonemia or hepatotoxicity
  • Symptomatic patients: 100 mg/kg (max 6 gm) IV (over 30 min) followed by 15 mg/kg IV Q 4 hours until normalization of NH3 or improving LFT
  • Asymptomatic patients: 100 mg/kg/day (max 3 mg) divided Q 6 hours.

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Hemoglobin Threshold in Septic Shock

  • Numerous trials have demonstrated the benefit of lower hemoglobin thresholds for blood transfusion in critically ill patients.
  • The recently published Transfusion Requirements in Septic Shock (TRISS) trial evaluated the effects on mortality of a lower versus higher hemoglobin threshold in ICU patients with septic shock.
  • The TRISS trial randomized 1005 patients to a lower hemglobin threshold (7 g/dL) or a higher hemoglobin threshold (9 g/dL). 
  • Overall, there was no difference in 90-day mortality between groups.
  • Patients randomized to the lower threshold received significantly fewer units without any increase in ischemic or adverse events.
  • Take Home Point: A hemoglogin threshold of 7 g/dL for blood transfusion appears effective for most patients with septic shock.

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Question

A neck ultrasound is performed during endotracheal intubation. What is labeled "A", what is labeled "B" and what's the diagnosis?

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Category: Cardiology

Title: Kounis Syndrome (Part II)

Posted: 10/12/2014 by Semhar Tewelde, MD (Updated: 9/20/2024)
Click here to contact Semhar Tewelde, MD

Kounis Syndrome (Part II)

- KS can develop from multiple etiologies: hymenoptera, proteins, vasoactive amines, histamine, acetylcholine, multiple antibiotics, and various medical conditions (angioedema, serum sickness, asthma, stress-induced cardiomyopathy).

- Hypersensitivity myocarditis and KS are two cardiac entities of allergic etiology affecting the myocardium and coronary arteries, respectively. These two entities can mimic each other and can be clinical indistinguishable.

- Presence of eosinophil’s, atypical lymphocytes, and giant cells on myocardial biopsy suggests hypersensitivity myocarditis.

- There is evidence showing use of corticosteroids with vasospastic angina with evidence of allergy or the presence of symptoms refractory to high-dose vasodilators has been reported to resolve symptoms.

 

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Category: Airway Management

Title: Concussion treatment

Keywords: Concussion, patient education (PubMed Search)

Posted: 10/11/2014 by Brian Corwell, MD
Click here to contact Brian Corwell, MD

There is no effective pharmacologic treatment known to hasten recovery from concussion. In future pearls we will examine possible interventions that may help.

The importance of educating our patients was demonstrated in two studies looking at concussion education. Patients were separated into 2 groups. The intervention group received a booklet of information discussing common symptoms of concussion, suggested coping strategies and the likely time course of recovery. At a 3 month follow-up evaluation, the intervention group reported fewer symptoms. This was repeated in pediatric patients with similar results.

Take Home: Consider taking the time to put such an information sheet together for concussed patients seen in the ED.

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Category: Pediatrics

Title: Pediatric Pneumonia

Posted: 10/10/2014 by Rose Chasm, MD (Updated: 9/20/2024)
Click here to contact Rose Chasm, MD

  • For uncomplicted community acquired pneumonia which is treated as an outpatient, high dose amoxicillin (80-90mg/kg/day) is the first-line antibiotic of choice.
  • Macrolides and third-generation cephalosporins are acceptable alternatives, but are not as effective due to pneumococcal resistance and lower systemic absorption, respectivley.
  • Hospitalization should be strongly considered for children younger than 2 months or premature due to an increased risk for apnea.
  • Patients hospitalized only for pneumonia, should be treated with ampicillin while those who are septic should be treated with a combination of vancomycin along with a second- or third- generation cephalosporin.

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Category: Toxicology

Title: Treatment for Calcium Channel Blocker Poisoning: What's the Evidence?

Keywords: calcium channel blocker, poisoning (PubMed Search)

Posted: 10/6/2014 by Bryan Hayes, PharmD (Emailed: 10/9/2014) (Updated: 10/11/2014)
Click here to contact Bryan Hayes, PharmD

In a precursor to a forthcoming international guideline on the management of calcium channel blocker poisoning, a new systematic review has been published assessing the available evidence.

A few findings from the systematic review:

  • The majority of literature on calcium channel blocker overdose management is heterogenous, biased, and low-quality evidence.
  • Interventions with the strongest evidence are high-dose insulin and extracorporeal life support.
  • Interventions with less evidence, but still possibly beneficial, include calcium, dopamine, norepinephrine, 4-aminopyridine (where available), and lipid emulsion therapy.

Stay tuned for the international guideline coming out soon. One treatment recommendation from the new guideline, reported at the 8th European Congress on Emergency Medicine last month, is not to use glucagon.

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Category: Neurology

Title: Evaluation of hydrocephalus in the ED

Keywords: Hydrocephalus, CSF shunt malfunction, ventriculomegaly, Evans' ratio (PubMed Search)

Posted: 10/8/2014 by WanTsu Wendy Chang, MD
Click here to contact WanTsu Wendy Chang, MD

Hydrocephalus is a disorder of cerebrospinal fluid (CSF) accumulation.  Acute obstructive hydrocephalus such as in subarachnoid hemorrhage and CSF shunt malfunction can cause a rapid rise in intracranial pressure.  Nonobstructive hydrocephalus is associated with subacute symptoms.   Clinical features of acute obstructive hydrocephalus include headache, blurred vision, papilledema, ocular palsies, nausea and vomiting, and decreased level of consciousness.

Evaluation of hydrocephalus in the ED should include neuroimaging, typically noncontrast head CT given its wide availability.  CT characteristics of hydrocephalus can be seen in Figure 1: ventriculomegaly with dilated 3rd ventricle, dilated 4th ventricle, and presence of temporal horns.

When evaluating patients with pre-existing hydrocephalus for worsening symptoms, such as in the evaluation of CSF shunt malfunctions, it is helpful to compare the head CT or MRI for interval ventricular enlargement.  Two simple measurements can be taken on a CT or MRI for objective comparisons (Figure 2).

  • Evans' ratio = A/B = Maximum width of frontal horns (A) divided by maximum width of inner skull (B) at the same CT/MRI level

  • C = Width of 3rd ventricle

Use of acetazolamide to decrease CSF production is not effective in long-term treatment of hydrocephalus.  About 75% of patients with hydrocephalus require CSF shunt placement.

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Attachments

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Category: Misc

Title: New UMEM Pearls App!

Keywords: app pearls apple google (PubMed Search)

Posted: 10/7/2014 by Kevin Hamilton
Click here to contact Kevin Hamilton

We are proud to announce the release of our new UMEM Pearls App, now available in the Apple App Store and the Google Play Marketplace! You will now be able to pull down pearl content for offline viewing, in addition to having all of the pearls in searchable format available on your mobile devices.

Click either of the following links on your mobile device to download your Pearls App today!

Get it on Google Play!

 

Get it on Apple App Store!



The ARISE Trial

Early, aggressive resuscitation and attention to detail are essential element of managing critically ill patients.  This past week the ARISE trial was published - a 2nd large, randomized control study to examine the benefit of protocolized vs. usual care in patients with severe sepsis and septic shock. 

What were the main findings?  After enrolling 1,600 patients who presented to the ED in severe sepsis or septic shock:

  • They found no difference in mortality between the control (usual care) and treatment arm (early goal-directed therapy)
  • Mortality was 18.6% vs. 18.8% at 90 days
  • No evidence that continuous ScVO2, Hgb target > 10 mg/dL (check out the TRISS trial), or use of inotropes with a normal cardiac index improved mortality

Bottom Line:  Resuscitation goals for the patient with septic shock should include:

  • Early antibiotics (source control)
  • Adequate volume resuscitation (preferably balanced, crystalloid solution)
  • End-organ perfusion (lactate normalization)

Additional therapeutic goals should be made on a patient by patient basis.  Reassess your patient frequently, pay attention to the details, and you will improve your patient’s mortality.

 

Suggested Reading

  1. The ARISE Investigators and the ANZICS Clinical Trials Group.  Goal-Directed Resuscitation for Patients with Early Septic Shock. N Engl J Med. 2014. [PubMed Link]
  2. Wessex ICS: The Bottom Line Review

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Question

7d old child presents with difficulty feeding,vomiting one time, and now with intermittent apneic episodes. What's the diagnosis? (Careful....this one is tricky!)

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Kounis Syndrome (Part I)

- Kounis & Zavras (1991) described the syndrome of allergic angina and allergic myocardial infarction, currently known as Kounis syndrome (KS). Braunwald (1998) noted vasospastic angina can be induced by allergic reactions, with mediators such as histamine and leukotrienes acting on coronary vascular smooth muscle.

- Two subtypes have been described: type I, occurring in patients without predisposing factors for CAD often caused by coronary artery spasm and type II, occurring with angiographic evidence of coronary disease when the allergic events induce plaque erosion or rupture.

- This syndrome has been reported in association with a variety of medical conditions, environmental exposures, and medication exposures. Entities such as Takotsubo cardiomyopathy, drug-eluted stent thrombosis, and coronary allograft vasculopathy also appear to be associated with this syndrome.

-  Clinical presentation includes: symptoms and signs of an allergic reaction and acute coronary syndrome: chest pain, dyspnea, faintness, nausea, vomiting, syncope, pruritus, urticaria, diaphoresis, pallor, palpitations, hypotension, and bradycardia. 

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Category: Pharmacology & Therapeutics

Title: Beta-Lactams in Critically Ill Patients: Current Dosing May be Inadequate

Keywords: beta-lactam, piperacillin/tazobactam, critically ill (PubMed Search)

Posted: 9/27/2014 by Bryan Hayes, PharmD (Emailed: 10/4/2014) (Updated: 10/4/2014)
Click here to contact Bryan Hayes, PharmD

Beta-lactam antimicrobials (penicillins, cephalosporins, and carbapenems) are frequently used for empiric and targeted therapy in critically ill patients. They display time-dependent killing, meaning the time the antibiotic concentration is above the minimin inhibitory concentration (MIC) is associated with improved efficacy.

Two new pharmacodynamic/pharmacokinetic studies suggest that current beta-lactam antimicrobial dosing regimens may be inadequate.

  • In patients from 68 ICUs across 10 countries, use of intermittent infusions (compared to extended and continuous infusions) and increasing creatinine clearance were risk factors for MIC target non-attainment. [1]
  • A second group specifically investigated the pulmonary penetration of piperacillin/tazobactam in critically ill patients and found that intrapulmonary exposure is highly variable and unrelated to plasma exposure and pulmonary permeability. [2]

Antimicrobial dosing in critically ill patients is complex. Current dosing of beta-lactams may be inadequate and needs to be studied further with relation to clinical outcomes.

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INFLUENZA

What is it?

  • Common disease that causes significant morbidity and mortality worldwide
    • Both seasonal and pandemic influenza occurs
    • Vaccination can decrease disease incidence and spread
    • Treatment can decrease disease severity
  • Orthomyxoviruses (RNA virus)
    • 6 genera

 

Why do we care about influenza?

  • Pandemic Influenza
    • Can infect and kill young, healthy people
    • 1918 H1N1 Influenza pandemic infected an estimated 500 million globally
      • Approximately 20% of the world’s population
    • Killed an estimated 50 million (may be as high as 100 million)
      • 2%-3% of the world’s population died
  • Seasonal Influenza
    • Most often causes severe disease in the very young, very old, and those with chronic illnesses
    • Estimated between 3-5 million cases of severe illness around the world annually
    • Between 250,000 and 500,000 deaths

 

Bottom line

  • Influenza is a potentially life threatening disease.
  • Both seasonal and pandemic influenza are global concerns.
  • Morbidity and mortality can be decreased through appropriate vaccination and treatment


Category: Toxicology

Title: Lily of the Valley

Keywords: Digoxin, Cardioactive Steroids, Digitoxin, Digoxin-specific Fab Fragment (PubMed Search)

Posted: 10/1/2014 by Kishan Kapadia, DO
Click here to contact Kishan Kapadia, DO

Cardioactive steroids are among the many treatments used for CHF, and for the control of ventricular response rate in atrial tachydysrhythmias. There are many sources of cardioactive steroids:

Pharmaceutial: Digoxin, Digitoxin

Plants: Oleander, Yellow Oleander, Foxglove, Lily of the Valley, Dogbane, Red Squill

Animal: Bufo marinus toad

It is a potent Na+-K+-ATPase inhibitor and can lead to hyperkalemia in acute ingestion with associated signs and symptoms of N/V, abdominal pain, bradycardia and possibly, hypotension.

Toxicity should be suspected with bidirectional ventricular tachycardia or atrial tachycardia with high-degree AV block

Therapeutic range of digoxin of 0.5 - 2.0 ng/mL is helpful but not a sole indicator of toxicity

Indication for antidote (Digoxin-specific Antibody Fragments) include:

1) Digoxin-related life-threatening dysrhythma

2) Serum K+ > 5.0 mEq/L in acute ingestion

3) Serum digoxin concentration >15ng/mL at any time, or >10 ng/mL 6 hours postingestion

4) Ingestion of 10 mg in adult; 4 mg in pediatric

5) Poisoning by non-digoxin cardioactive steroid

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The last Back to the Basics post discussed the use of vasopressors to improve hemodynamics by increasing arterial (and venous) tone. This time we’ll discuss the use of agents to increase inotropy for patients with severe systolic dysfunction / failure.

Dobutamine: a direct b1 and b2-receptors agonist. It has no peripheral vasoconstrictor properties, so if blood pressure increases it occurs secondary to increased cardiac output. Unfortunately, blood pressure may be decreased in some patients due to its peripheral vasodilatory effects; in these cases it may need to be used with a vasopressor.

Milrinone: augments contractility by increasing intracellular Ca levels via cellular phosphodiesterase inhibition. Because it does not work on beta-receptors, it might be preferred for patients taking beta-blockers requiring inotropic support. It may cause peripheral vasodilation and hypotension, but this may be a benefit if pulmonary artery pressure is elevated as reductions in pulmonary artery pressure lead to improvements in right ventricular function. It has a long-half life and should be avoided in patients with renal impairment.

Dopamine: chemical precursor to norepinephrine and technically a vasopressor. At moderate doses (3-10 mcg/kg/min) it works on beta-receptors to increase myocyte contractility. At higher doses works primarily as a vasopressor, which may reduce cardiac output due to higher afterload.

Norepinephrine/epinephrine: has alpha and beta properties that lead to increased peripheral vasoconstriction, but also increases inotropy and chronotropy (faster heart rate)

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Question

Person presents with painless vision loss after seeing flashes of light. Ultrasound is below. What's the diagnosis?

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Ventricular Arrhythmias Originating from the Moderator Band

- Ventricular arrhythmias originating from the moderator band (MB) often have a distinct morphology

- Typically MB arrhythmias have a left bundle branch block pattern, QRS with a late precordial transition (>V4), a rapid down stroke of the QRS in the precordial leads, and a left superior frontal plane axis

- MB arrhythmias are often associated with PVC-induced ventricular fibrillation

- Catheter ablation is quite effective at termination of the arrhythmias and facilitated with intracardiac echocardiography (ICE)

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Category: Orthopedics

Title: "I have sciatica, I want a MRI and I want it now"

Keywords: Sciatica, radiculopathy, imaging (PubMed Search)

Posted: 9/19/2014 by Brian Corwell, MD (Emailed: 9/27/2014) (Updated: 9/27/2014)
Click here to contact Brian Corwell, MD

Back pain with radiculopathy can be very distressing to a patient and they have heard from their medically savvy neighbor that a MRI is the way to go. Now, armed with this knowledge, they are in your ED with earplugs in hand...

A few minutes of reassurance and education can save in both cost and ED throughput.

In one study researchers performed MRIs on asymtomatic adult patients.

               Almost two-thirds (64%) had abnormal discs

               Just over half (52%) had bulging discs

               Almost a third (31%) had disc protrusions

Further, finding a bulging disc already suggested by your history and physical examination does not change management. The majority of these patients improve with conservative treatment within four to to six weeks.

Restrict ED MRI use for the evaluation of suspected cauda equina, epidural abscess and spinal cord compression.