UMEM Educational Pearls

Category: Toxicology

Title: Ondansetron Induced Dystonia

Keywords: ondansetron, dystonia (PubMed Search)

Posted: 2/6/2014 by Fermin Barrueto, MD (Updated: 7/22/2024)
Click here to contact Fermin Barrueto, MD

Ondansetron (Zofran) is a great anti-emetic that, since it has gone generic, is also inexpensive. High dose ondansetron has been reported to cause QT prolongation and that practice is largerly discontinued now in the oncology world. Another uncommon adverse drug reaction may be dystonia. Though we think of ondansetron as a 5-HT3 blocker and should not cause the dystonic reaction like we see in metoclopramide, there are case reports of this reaction occurring.

 

 

 

 

 

Ondansetron-induced dystonia, hypoglycemia, and seizures in a child.
Patel A, Mittal S, Manchanda S, Puliyel JM.
Ann Pharmacother. 2011 Jan;45(1):e7.
 
 


Category: Pharmacology & Therapeutics

Title: Tranexamic Acid in Anterior Epistaxis

Keywords: anterior epistaxis, tranexamic acid, antifibrinolytic (PubMed Search)

Posted: 2/6/2014 by Ellen Lemkin, MD, PharmD
Click here to contact Ellen Lemkin, MD, PharmD

Tranexamic Acid (TXA) topically applied was compared to anterior nasal packing in 216 patients with acute anterior epistaxis. Cotton pledgets (15 cm) soaked in injectable TXA (500 mg/5 ml) were inserted into the bleeding nostril and removed after bleeding had arrested. This was compared to standard anterior packing.

RESULTS

                                                                   TXA            Anterior packing

% pts bleeding stopped in 10 min:           71%           31.2%                

Discharge after 2 hours                           95.3%           6.4%

Rebleeding in 24 h hours                          4.7%        11%

Satisfaction scores                                    8.5               4.4

 

Bottom line: topical tranexamic acid looks promising for control of uncomplicated anterior epistaxis.

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Category: International EM

Title: Vulnerable Road Users

Keywords: road traffic accidents, international, global, public health (PubMed Search)

Posted: 2/5/2014 by Andrea Tenner, MD (Updated: 7/22/2024)
Click here to contact Andrea Tenner, MD

General Information:

  • 1.24 million people die each year on the world's roads
  • 50% of those dying on the world’s roads are vulnerable road users (VRUs-- those most at risk in traffic, i.e. those unprotected by an outside shield)
    • 23% motorcyclists, 22% pedestrians, 5% cyclists
    • Children and elderly are overrepresented among victims

Area of the world affected:

  • In 2010, low- and middle-income countries had higher road traffic fatality rates (18.3 and 20.1 per 100,000, respectively) compared to high-income countries (8.7).
  • The African region had the highest road traffic fatality rate, at 24.1, while the European region had the lowest rate, at 10.3.

Relevance to the US physician:

  • While public health measures are key in reducing the risk to VRUs, improving the provision of emergency medical services may also result in a higher proportion of victims surviving on the road or on the way to a health clinic.
  • Travelers should also be mindful of the risks of motorcycles, bicycles, and walking along the roadside

Bottom Line:

VRU traffic injuries are the greatest challenge of today's worldwide road safety. 

University of Maryland Section of Global Emergency Health

Author: Terrence Mulligan DO, MPH

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Category: Critical Care

Title: Mechanical Ventilation During ECMO

Keywords: VV-ECMO, mechanical ventilation, ultra-lung protective ventilation (PubMed Search)

Posted: 2/4/2014 by Mike Winters, MBA, MD
Click here to contact Mike Winters, MBA, MD

Mechanical Ventilation During ECMO

  • ECMO is a rapidly emerging therapy for critically ill patients with severe acute respiratory failure (VV-ECMO) and circulatory failure (VA-ECMO).
  • Mechanical ventilation (MV) settings may have important effects on patients receiving either VV- or VA-ECMO.
  • Though no large, randomized trials, consensus guidelines and expert opinion recommend the following initial settings for patients receiving VV-ECMO:
    • Tidal volume: < 4 ml/kg predicted body weight
    • Plateau pressure: < 25 cmH2O
    • PEEP: 10-15 cmH2O
    • FiO2: titrated to maintain sats > 85%
    • RR: 4 to 6 breaths per minute

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Question

34 year-old left-hand dominant male sustained injury to left hand after his pressurized greasing-gun discharged into the palm of his hand. He has a small lac to the hand but is in extreme pain. On exam his hand is very puffy and he is neurovascularly intact (XR below) What is the next step in management? 

 

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Myocardial Infarction in Women After Childbirth

World Health Organization reports that obesity is the 5th leading cause of global death with the highest impact on women <65 years of age

The association of obesity and cardiovascular risk in young women is currently being researched

A recent nationwide cohort looking at obesity and future cardiovascular risk looked at Danish women giving birth (2004-2009) and followed them a median time of 4.5 years

This study grouped women via pre-pregnancy body mass index (BMI)

                                            1. Underweight (BMI <18.5)     

                                            2. Normal weight (BMI <25)

                                3. Overweight (BMI <30)

                                4. Obese (BMI >30)

Data revealed that healthy women of fertile age, pre-pregnancy obesity alone was associated with increased risk of myocardial infarction in the years after childbirth

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Category: Pharmacology & Therapeutics

Title: Minimum Methadone Dose to Prevent Withdrawal

Keywords: methadone, withdrawal (PubMed Search)

Posted: 1/23/2014 by Bryan Hayes, PharmD (Emailed: 2/1/2014) (Updated: 2/1/2014)
Click here to contact Bryan Hayes, PharmD

In most situations (dependant on state laws and institutional policies), methadone-maintained patients enrolled in a drug abuse program are best managed by continuing methadone at the usual maintenance levels with once-a-day oral administration.

Pearl: In the event the methadone clinic is closed and/or the dose cannot be verified, 30-40 mg (10-20 mg IM) is generally enough to prevent withdrawal in most patients.

This is only a short-term measure and some patients may require additional methadone. Full doses of methadone should be reinstituted as soon as possible.

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Category: Toxicology

Title: Resistant Etoh Withdrawal - Try Dexmedetomidine (Precedex)

Keywords: dexmedetomidine, alcohol withdrawal (PubMed Search)

Posted: 1/30/2014 by Fermin Barrueto, MD (Updated: 7/22/2024)
Click here to contact Fermin Barrueto, MD

 

If you are treating an alcohol withdrawal patient and benzodiazepines are not working, try dexmedetomidine (precedex). This centrally acting alpha-2 agonist was utilized in 18 ICU patients and was shown to be safe. Average diazepam dose was 193 mg IV and lorazepam dose was 9 mg IV in these patients. Haloperidol was utilized in 3 of these patients which is not an effective therapy for alcohol withdrawal (could worsen due to QT prolongation, decrease seizure threshold and anticholinergic effects).
 
Still requires further research and not sure about the physiologic mechanism dexmedetomidine would actually treat alcohol withdrawal aside from sedating. There is the added benefit of maintaining airway reflexes versus propofol. This case series shows the experience with this drug regimen.
 
 
 
 
1. Tolonen J et al. Dexmedetomidine in addition to benzodiazepine-based
sedation in patients with alcohol withdrawal delirium. Eur J Emerg
Med. 2013. 20:425-427.


Category: International EM

Title: Tropical Medicine in Your Backyard

Keywords: Virus, Fever, West Nile, Dengue (PubMed Search)

Posted: 1/29/2014 by Andrea Tenner, MD
Click here to contact Andrea Tenner, MD

Case Presentation: A 63 year old woman from Texas with no recent international travel presents to the ED with persistent fatigue which onset a month ago and is associated with anorexia and occasional fevers and chills.  She has been to her family doctor who tested her for a number of viral illnesses and was told she had West Nile virus.

Clinical Question:

What other febrile illness could this be?

Answer:

This patient had dengue.  Dengue is now endemic in the US, and locally-acquired cases have been reported in Florida, Texas and Hawaii. The fatigue and anorexia are typical and can last for weeks after other symptoms have resolved. 

West Nile virus testing may be falsely positive when another flavivirus is present such dengue, yellow fever or Japanese encephalitis. 

Bottom Line:

Other possible illnesses like dengue should be considered in patients who have tested positive for West Nile virus.

 

University of Maryland Section of Global Emergency Health

Author: Jenny Reifel Saltzberg, MD, MPH

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NSSTIs occur secondary to toxin-secreting bacteria; NSSTIs are surgical emergencies with a high-morbidity / mortality

Risk factors: immunocompromised host (DM, AIDS, etc.), intravenous drug use, malnourishment, peripheral vascular disease

Type I (polymicrobial; most common), Type II (monomicrobial; typically clostridia, streptococci, staph, or bacteroides), Type III (Vibrio vulnificus; seawater exposure)

Signs / Symptoms: pain out of proportion to exam (occasionally no pain at all), skin findings (blistering / bullae, gray-skin discoloration, or “Dishwater-like” discharge), or systemic toxicity (altered mental status, elevated lactate, etc.)

Diagnostic radiology

  • Xray (shows gas); low sensitivity; CT scan (gas / tissue stranding); sensitivity is also low
  • MRI can over-diagnose NSSTI and should not be used routinely
  • Bedside ultrasound may demonstrate fluid or gas collections in deeper tissues (see clip below)

Treatment is emergent surgical debridement with simultaneous hemodynamic resuscitation PLUS broad-spectrum antibiotics; consider clindamycin becuase it has anti-toxin activity

Adjunctive therapies include Intravenous intraglobulin (neutralizes toxins secreted by bacteria) and hyperbaric oxygen

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Question

32 year-old with diabetes presents with fever, erythema, and warmth of his lower extremity; his leg is not particularly painful. He is diagnosed with cellulitis, started on antibiotics, and admitted to the hospital. While boarding in the Emergency Department he becomes rigorous and hypotensive. An ultrasound of his cellulitis is performed and is shown below. What’s the diagnosis?

 

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Category: Cardiology

Title: Extremely Fast & Wide Complex Regular Tachycardia

Keywords: Wide complex tachycardia, ventricular tachycardia (PubMed Search)

Posted: 1/26/2014 by Ali Farzad, MD (Updated: 3/23/2014)
Click here to contact Ali Farzad, MD

Question

A 48 year old woman has acute chest pain and palpitations over the past several hours. She has felt similar palpitations in the past but never sought medical attention. She arrives to your ED alert and anxious. HR = 270, BP=130/100. ECG is below. What’s the diagnosis and treatment?

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Attachments

1401260828_JEM.WCT.Jan14.pdf (1,636 Kb)



Category: Orthopedics

Title: Pellegrini Stieda lesion

Keywords: MCL, knee, (PubMed Search)

Posted: 1/17/2014 by Brian Corwell, MD (Emailed: 1/25/2014) (Updated: 1/25/2014)
Click here to contact Brian Corwell, MD

Pelllegrini-Stieda lesion

Ossified post-traumatic lesions at the MCL adjacent to the femoral attachment site of the medial femoral condyle.

Mechanism is likely from an avulsion injury that subsequently calcifies after the initial trauma.

Often an incidental finding on plain films.

If symptomatic, refer to ortho as an outpatient

If not symptomatic, no treatment is indicated

 

http://images.radiopaedia.org/images/30076/b62e61e83241e30f2da693901edcdc_gallery.jpg

http://www.imageinterpretation.co.uk/images/knee/PELLEGRINI%20STIEDA2.jpg



Category: Toxicology

Title: Bioaccumulation and the "Therapeutic" Overdose

Keywords: pharmacology (PubMed Search)

Posted: 1/23/2014 by Fermin Barrueto, MD (Updated: 7/22/2024)
Click here to contact Fermin Barrueto, MD

Everyone has admitted an altered mental status, patient or bradycardic patient and all of your test results are coming back normal except for a mild increase in creatinine. Take a look at the medication list. Creatinine is a poor indicator of renal function and GFR may be severely impaired even with a mild elevation of creatinine. If you have a predominantly renally excreted drug, you can see toxic effects of a drug even if administered at therapeutic levels.

Common bradycardia inducing medication that is renally cleared: atenolol (very high renal excretion) and digoxin (70%).

Altered Mental Status and on Keppra? Keppra is 100% renally cleared!

Ask your pharmacist for help with the medication list with renal or hepatic insufficiency.



Category: International EM

Title: Know your Slytherins

Keywords: International, snake, venom, (PubMed Search)

Posted: 1/22/2014 by Andrea Tenner, MD
Click here to contact Andrea Tenner, MD

98% of venomous snake bites in the US are due to pit vipers.  Occasionally a snake bite is from an exotic venomous snake being kept as a pet.  In 2005, 142 exotic poisonous snakes were reported to poison control.  It can be very challenging to find antivenom for these exotic animals.

Antivenom is usually specific to a family or subfamily, so the snake must be identified.  Most exotic snake owners will know the common name and possibly the scientific name of the animal.

The WHO database of venomous snakes can help with identification of the species and will list antivenom available globally.

Poison centers are essential to help locate the antivenom and assist with treatment.

Relevance to the EM Physician:

When a patient presents with an exotic snake envenomation, the WHO website below can be helpful to identify the species and possible antivenom.  

http://apps.who.int/bloodproducts/snakeantivenoms/database/

 

University of Maryland Section of Global Emergency Health

Author: Jenny Reifel Saltzberg

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Category: Critical Care

Title: A-lines: A Significant Source of Preventable Blood Stream Infections

Keywords: arterial line, catheter related blood stream infections (PubMed Search)

Posted: 1/20/2014 by John Greenwood, MD (Emailed: 1/21/2014) (Updated: 1/21/2014)
Click here to contact John Greenwood, MD

 

Arterial Catheter-Related Blood Stream Infections

Whether arterial lines are a potential source of catheter-related blood stream infections (CRBSIs) is highly-debated; however, based on a recent systematic review they are an under recognized and significant source of CRBSIs.

  • IncidenceIn systematically cultured arterial catheters, the infection rate was 1.6 infections/1,000 catheter days which is similar to what has been reported for infections associated with short-term CVC's.
     
  • Location: Femoral a-lines are more likely than radial a-lines to be a source of a CRBSI. Femoral a-line CRBSIs occurred in 1.5% of all catheters (95% CI, 0.8–2.2%), which is higher than radial CRBSI, with a relative risk of infection 1.94 times greater than those placed at the radial site.
     
  • TechniqueOnly one study specifically evaluated the impact of full barrier precautions versus using sterile gloves only for peripheral a-lines, and it did not find any significant difference in BSI. No study has evaluated the impact of maximal barrier precautions for femoral, axillary, and brachial arterial catheters.
     
  • Dressing: The risk of infection was significantly decreased with the use of chlorhexidine-impregnated dressings (ex: BioPatch).

 

Bottom Line(s) 

  1. Arterial lines appear to be a significantly under recognized source of CRBSI's in critically-ill patients.  If you are deciding to place an a-line for invasive blood pressure monitoring, strongly consider the radial site and use a chlorhexidine sponge or dressing to try and minimize the risk of future BSI.
     
  2. There is a paucity of data regarding the utility of maximal barrier techniques when inserting peripheral arterial lines.  With arterial catheter infection rates approaching that of central venous catheters, we should probably be inserting a-lines with the same sterile technique.

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Question

50 year-old male intubated for respiratory distress. Ultrasound is used post-intubation to confirm tube placement and the following images are obtained. What's the diagnosis?

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Pacing Atrioventricular Block

 - Atrioventricular (AV) block is classically treated with restoration of heart rate via right ventricular pacing, however high rates of right ventricular pacing is associated w/ left  ventricular systolic dysfunction  

- A recent multi-center randomized control trial (RCT) assessed the efficacy of right vs biventricular pacing in heart failure w/ AV block [BLOCK HF Trial]

- Primary outcomes of: morbidity, mortality, and adverse left ventricular remodeling were shown to be significantly lower in biventricular vs right ventricular pacing 

- In patients with a high rate of pacing and/or an  abnormally low left ventricular ejection fraction biventricular pacing may be more advantageous than conventional right ventricular pacing

 

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Category: Misc

Title: Cause of Post-Operative Fever

Keywords: Postoperative, fever, cause (PubMed Search)

Posted: 1/18/2014 by Michael Bond, MD (Updated: 7/22/2024)
Click here to contact Michael Bond, MD

Post Operative Fever is extremely common, and with the increase in same day surgery this is a common complaint presenting to the ED.  The mnemonic "5Ws" are often taught to remember the causes. They are:

  • Wind - Pneumonia, aspiration, pulmonary embolism, and atelectasis
  • Water - urinary tract infection
  • Walking - Deep Venous Thrombosis or pulmonary embolism
  • Wound - surgical wound infection
  • Wonder drugs - Drug fever, or infection due to indwelling lines, or a reaction to blood products

Though many surgical textbooks report that atelectasis is the most common cause of early post-operative fever,  some even claiming that it is responsible for over 90% of febrile episodes in the first 48 hours after surgery; a recent review in CHEST (reference below) showed that there is no evidence to support this. We often see atelectasis in medical patients too, and few if any of them have fever.  The CHEST review found that there was no clear evidence that atelectasis causes fever at all.

Pearl:  Temperature >38.9C should raise concern for a true infection, where lower temperatures can be due to pulmonary embolism, DVT, drug fever, etc….
 

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Category: Pediatrics

Title: Maintenance Sodium in the Pediatric Patient

Keywords: hyponatremia, maintenance fluid (PubMed Search)

Posted: 1/17/2014 by Jenny Guyther, MD (Updated: 7/22/2024)
Click here to contact Jenny Guyther, MD

 
What sodium base should be given to children who are unable to eat?  Recent studies have suggested that the traditional teaching of 0.45% normal saline (NS), 0.33% NS or 0.2% NS may cause iatrogenic hyponatremia when compared to an isotonic solution (0.9% NS, Ringers lactate or Hartmann's solution).  
 
A meta-analysis of 8 studies with 855 patients examined the rate of hyponatremia when using hypotonic versus isotonic solutions.
-Studies included were randomized controlled trials with children age 1 month to 17 years.
-Children needing any type of resuscitation were excluded.
-Hyponatremia was defined as a sodium < 136 mmol/L.
-There is a higher risk when using hypotonic fluids for developing hyponatremia (RR 2.24) and severe hyponatremia (RR 5.29).
-The decrease in sodium was greater when hypotonic solutions were used.
-No significant difference in the rate of hypernatremia (Na>150 mmol/L)
-The type of fluid given (not rate) correlated with the risk of hyponatremia.
-Conclusions could not be drawn on the clinical significance of the iatrogenic hyponatremia
 
Bottom line: Make a conscience decision about maintenance fluids.  Be sure to monitor Na levels for patients that you place on maintenance fluids and who are in your ED for prolonged periods of time.

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