UMEM Educational Pearls

Category: Vascular

Title: Pulmonary Embolism Rule Out

Keywords: D-Dimer, PE, Well's (PubMed Search)

Posted: 7/14/2007 by Rob Rogers, MD (Emailed: 7/8/2007) (Updated: 6/25/2019)
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Update on the Wells Criteria for PE-patients with a score of 4 or less (which means low to moderate probability) can be considered for a "d-dimer negative" rule out approach. This is a bit of a change from the low risk only approach. Additionally, the British Thoracic Society guidelines support the low and moderate risk group patient rule out strategy. So, if you have a low or even moderate risk patient, you can use the approach of obtaining a highly sensitive d-dimer and if it is negative, the hunt for PE is over.

Category: Toxicology

Title: Cyanide

Keywords: cyanide, poisoning, hydroxycobalamin (PubMed Search)

Posted: 7/14/2007 by Fermin Barrueto, MD (Emailed: 7/8/2007) (Updated: 6/25/2019)
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Cyanide Presents with arterialization of venous blood (venous blood draw looks like ABG) Reason: o Hemoglobin is not able to offload oxygen o CN poisons cytochrome c oxidase preventing conversion of oxygen to water and thus production of ATP Old antidote: sodium thiosulfate New antidote: hydroxycobalamin binds CN producing cyanocobalamin (Vit B12) When you give it expects a dip in pulse because of its blue color. Remember CN will give you a beautiful 100% pulse all the way to death. Lee J, et al. Potential interference by hydroxocobalamin on cooximetry hemoglobin measurements during cyanide and smoke inhalation treatments. Ann Emerg Med. 2007 Jun;49(6):802-5. Epub 2007 Jan 8.

Category: Cardiology

Title: Dyspnea

Posted: 7/14/2007 by Amal Mattu, MD (Emailed: 7/8/2007) (Updated: 6/25/2019)
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Elderly are more likely to present with dyspnea (49% [the most common anginal equivalent]), diaphoresis (26%), nausea and vomiting (24%), and syncope (19%) as a primary complaint. The takeaway point: always get that ECG early in elderly patients with these complaints, even when CP is absent!

Category: Critical Care

Title: Pacer Cordis

Keywords: Pacer, Cordis, transvenous (PubMed Search)

Posted: 7/14/2007 by Mike Winters, MD (Emailed: 7/8/2007) (Updated: 6/25/2019)
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Make sure the Cordis is the right size when floating a pacing wire * At some point in your career, you may need to "float" a transvenous pacing wire * When inserting the wire, you need to make sure you have the right size Cordis * In general, a pacing wire should be inserted through a 6F Cordis (0.198 mm) * Many introducer kits have a 7.5F Cordis (0.2475mm) that is used for insertion of a PAC * Blood loss, infection, and air embolism are risks that can occur when the Cordis catheter used is too large Reference: 1. Marcucci L, ed. Avoiding common ICU errors. Philadelphia; Lippincott Williams & Wilkins; 2007:275-6.

Category: Toxicology

Title: Valproic acid toxicity

Keywords: Valproic acid (PubMed Search)

Posted: 10/16/2014 by Hong Kim, MD, MPH (Emailed: 6/25/2019)
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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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Category: Airway Management

Title: Flush-Rate O2 for Preoxygenation prior to RSI

Keywords: RSI, Preoxygenation (PubMed Search)

Posted: 9/13/2016 by Rory Spiegel, MD (Emailed: 6/25/2019)
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During rapid sequence intubation (RSI) we endeavor to avoid positive pressure ventilation, prior to securing a definitive airway. As such, an adequate buffer of oxygen is necessary to ensure a safe apneic period. This process involves replacing the residual nitrogen in the lung with oxygen. It has been demonstrated that a standard nonrebreather (NRB) mask alone does not provide a high enough fractional concentration of oxygen (FiO2) to optimally denitrogenate the lungs (1). Even when a nasal cannula at 15L/min is utilized in addition to the NRB, the resulting FiO2 is not ideal. A bag-valve mask (BVM) with a one-way-valve or PEEP valve has been demonstrated to provide oxygen concentrations close to that of an anesthesia circuit. But its effectiveness is drastically reduced if a proper mask seal is not maintained during the entire pre-oxygenation period (1). This is not always logistically possible in the chaos of an Emergency Department intubation.

A standard NRB with the addition of flush-rate oxygen appears to be a viable alternative. Recently published in Annals of Emergency Medicine, Driver et al demonstrated that a NRB with wall oxygen flow rates increased to maximum levels, rather than the standard 15L/min, provided end-tidal O2 (ET-O2) levels similar to an anesthesia circuit (2). 

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Category: Critical Care

Title: Utilization of the Mechanical Ventilator in Cardiac Arrest

Keywords: CPR, Cardiac Arrest (PubMed Search)

Posted: 11/15/2016 by Rory Spiegel, MD (Emailed: 6/25/2019)
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It is well documented that when left to our own respiratory devices we will consistently over-ventilate patients presenting in cardiac arrest (1). A simple and effective method of preventing these overzealous tendencies is the utilization of a ventilator in place of a BVM. The ventilator is not typically used during cardiac arrest resuscitation because the high peak-pressures generated when chest compressions are being performed cause the ventilator to terminate the breath prior to the delivery of the intended tidal volume. This can easily be overcome by turning the peak-pressure alarm to its maximum setting. A number of studies have demonstrated the feasibility of this technique, most recently a cohort in published in Resuscitation by Chalkias et al (2). The 2010 European Resuscitation Council guidelines recommend a volume control mode at 6-7 mL/kg and 10 breaths/minute (3).

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Category: Toxicology

Title: Opioid Prescription Drug Abuse - The Pattern of Abuse

Keywords: opioids, toxicology (PubMed Search)

Posted: 11/20/2014 by Fermin Barrueto, MD (Emailed: 6/25/2019) (Updated: 6/25/2019)
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The pattern of prescription drug abuse continues to center around semisynthetic opioids like oxycodone and hydrocodone. Federal regulations have now raised hydrocodone to a schedule II drug like oxycodone. Despite efforts, the slope for natural and semisynthetic opioids remains steep.  The ED measures of education, limit prescriptions for acute pain, minimize number of days/pills prescribed and utlize the prescription drug monitoring program are some basics that can assist you in better prescribing habits.

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Category: Toxicology

Title: Opioid Prescription Drug Abuse - The Pattern of Abuse

Keywords: opioids, toxicology (PubMed Search)

Posted: 11/20/2014 by Fermin Barrueto, MD (Emailed: 6/25/2019) (Updated: 6/25/2019)
Click here to contact Fermin Barrueto, MD

The pattern of prescription drug abuse continues to center around semisynthetic opioids like oxycodone and hydrocodone. Federal regulations have now raised hydrocodone to a schedule II drug like oxycodone. Despite efforts, the slope for natural and semisynthetic opioids remains steep.  The ED measures of education, limit prescriptions for acute pain, minimize number of days/pills prescribed and utlize the prescription drug monitoring program are some basics that can assist you in better prescribing habits.

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Category: Orthopedics

Title: Sports Hernia/Athletic pubalgia

Keywords: Sports Hernia, groin pain (PubMed Search)

Posted: 4/6/2014 by Brian Corwell, MD (Emailed: 6/25/2019)
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Sports Hernia/Athletic pubalgia

 

Hx: Gradually increasing lower abdominal/proximal adductor pain. Usually activity related, resolves with rest. Frequent return despite rest when sports activity resumes.

Most common in athletes who perform cutting/maneuvers in addition to frequent acceleration/deceleration. Think ice hockey and soccer.

Bilateral symptoms not uncommon.

PE:  Resisted sit up with palpation of the inferolateral edge of the distal rectus may recreate symptoms. Similarly, resisted hip adduction may elicit symptoms. 

If for no other reason than to make the diagnosis harder to make, valsalva induced pain may also occur.

Fluoroscopic guided injections can be helpful to isolate the site of pain generation.

First line therapy is rest, non-narcotic analgesia and physical therapy.

With surgery, >80% return to pre injury level of play.

 

http://atlantasportsmedicine.com/orthopedic-surgeon/wp-content/uploads/2009/11/groin-injuries.jpg

 

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Category: Neurology

Title: Phantoms in EMS

Keywords: Stroke, EMS, prehospital care, tPA, emergency medical services, fibrinolysis (PubMed Search)

Posted: 5/15/2014 by Ben Lawner, DO (Emailed: 6/25/2019) (Updated: 7/3/2014)
Click here to contact Ben Lawner, DO

The Prehospital Acute Neurological Treatment and Optimization of Medical Care in Stroke Study (PHANTOM-S) was a randomized prehospital  clinical trial. On certain days, a dedicated Stroke Emergency Mobile (STEMO) responded to possible ischemic stroke incidents. Outcomes measured included time to thrombolysis and adverse events such as intracerebral hemorrhage. As opposed to usual prehospital care, a STEMO ambulance was equipped with a CT scanner, point of care laboratory, and a neurologist. According to the study, STEMO use resulted in reduced time to treatment (tPA) without adverse events. 

Though this trial did not specifically measure clinical endpoints, it addresses issues central to the delivery of specialized prehospital care:

1) Are there certain conditions which might warrant a tailored, super-specialized EMS response?
2) Are EMS systems capable of delivering definitive care to the patient as opposed to delivering the patient to definitive care? 

Stateside study has already started.  The Houston Fire Department, in partnership with UTHeath, has already loosed a "Mobile Stroke Unit" on the streets. Like the STEMO, the specialized ambulance will be University hospital based, carry a neurologist, and have the capability to administer tPA. 

STEMO pictures courtesy of the "NeuroEMS Blog"
http://www.neuroems.com/2014/05/14/tpa-in-the-truck-results-of-the-phantom-s-trial/

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Category: Critical Care

Title: Predicting peri-Intubation hypotension

Keywords: peri-Intubation, shock index (PubMed Search)

Posted: 2/7/2017 by Rory Spiegel, MD (Emailed: 6/25/2019)
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Identifying patients at risk of hypotension during intubation is not always straight forward. The prevalence of peri-intubation hypotension in the Emergency Department has been demonstrated to be approximately 20%.1 And while certain variables increase the likelihood of peri-intubation hypotension (ex. Shock index> 0.80), no single factor predicts it accurately enough to be used at the bedside.2 In the majority of patients undergoing intubation, clinicians should be prepared for peri-intubation hypotension with either vasopressor infusions or push dose pressors.

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Category: Toxicology

Title:

Keywords: vaping (PubMed Search)

Posted: 7/6/2018 by Kathy Prybys, DO (Emailed: 6/25/2019) (Updated: 6/25/2019)
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 Vaping. is the use of electronic device to heat a liuid to generate an aersol or vapor to inhale. The lqiud usually contains nicotine, propylene gylcol, gylcerine, and flavoring. E cigarettes are popular for various reasons simulate tobacco use, odorless, believed to be healthier than tobacco, circumvent no smoking laws, delivery system for cannabinoids. The JUUL, is a sleekly designed e-cigarette which resembles a a USB drive and is increasingly being used by youth and young adults.

 

Although e-cigarettes cause less health effects than tobacco, current evidence indicates that they are not without risk.


Category: Toxicology

Title: Hydrofluoric Acid Burns

Keywords: hydrofluoric acid, burn, chemical burn, HFA, calcium gluconate (PubMed Search)

Posted: 9/5/2010 by Dan Lemkin, MD (Emailed: 6/25/2019) (Updated: 10/2/2010)
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Hydrofluoric acid is a weak acid used primarily in industrial applications for glass etching and metal cleaning/plating. It is contained in home rust removers. Although technically a weak acid, it is very dangerous and burns can be subtle in appearance while having severe consequences.

Hydrofluoric acid burn

Wilkes G. Hydrofluoric Acid Burns. Jan 28, 2010. 
http://emedicine.medscape.com/article/773304-overview

  • 2 mechanisms that cause tissue damage*
    • corrosive burn from the free hydrogen ions
    • chemical burn from tissue penetration of the fluoride ions
  • Clinical features*
    • Cutaneous burns - absent findings to white-blue appearance
    • Pulmonary edema
    • Hypocalcemia, hyperkalemia, hypomagnesemia
  • Treatment*
    • Decontaminate by irrigation with copious amounts of water.
    • With any evidence of hypocalcemia, immediately administer 10% calcium gluconate IV.
    • Cutaneous burns:
      • Apply 2.5% calcium gluconate gel to the affected area. If the proprietary gel is not available, constitute by dissolving 10% calcium gluconate solution in 3 times the volume of a water-soluble lubricant (eg, KY gel). For burns to the fingers, retain gel in a latex glove.
      • If pain persists for more than 30 minutes after application of calcium gluconate gel, further treatment is required. Subcutaneous infiltration of calcium gluconate is recommended at a dose of 0.5 mL of a 5% solution per square centimeter of surface burn extending 0.5 cm beyond the margin of involved tissue (10% calcium gluconate solution can be irritating to the tissue).
        • Do not use the chloride salt because it is an irritant and may cause tissue damage.

*Extracted from emedicine article.

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Category: Critical Care

Title: Oxygenation goals

Posted: 3/11/2009 by Mike Winters, MD (Emailed: 6/25/2019) (Updated: 6/25/2019)
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Oxygenation goals

  • In recent pearls we have talked about 'lung protective' ventilation strategies to reduce volutrauma, barotrauma, and oxygen toxicity.
  • Using 'lung protective' strategies, such as low tidal volumes, results in higher levels of CO2 and a lower pH.  These are tolerated in favor of lower and safer alveolar pressures.
  • In addition to higher pCO2 values and lower pH, oxygenation goals are slightly lower than conventional teaching.
  • In these patients, you want to maintain SpO2 > 88% and PaO2 > 55 mm Hg.

Category: Vascular

Title: D-Dimer in Pregnancy

Keywords: D-Dimer, Pregnancy (PubMed Search)

Posted: 7/9/2008 by Rob Rogers, MD (Emailed: 6/25/2019) (Updated: 6/25/2019)
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D-Dimer levels are known to be elevated in pregnancy. But how high is too high and can this test be used in the workup of VTE in pregnant patients?

Recent literature indicates that D-dimer levels in each of the three trimesters are approximately 39% higher: 700, 1000, and 1400 ng/dL for each trimester (normal cutoff 500 ng/dL). So, figure out what trimester your patient is in and use the corresponding D-Dimer level for that trimester.

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Category: Visual Diagnosis

Title: An alcoholic with fever and cough

Keywords: fever, cough, alcoholic (PubMed Search)

Posted: 5/7/2012 by Rob Rogers, MD (Emailed: 6/25/2019) (Updated: 6/25/2019)
Click here to contact Rob Rogers, MD

Question

An alcoholic patient presents with a cough, fever, and very foul smelling breath (worse than usual)

What's the diagnosis? And what are the risk factors?

 

 

Show Answer

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Category: Toxicology

Title: Octreotide for Pediatric Sulfonylurea Poisoning

Keywords: octreotide, sulfonylurea (PubMed Search)

Posted: 4/12/2013 by Bryan Hayes, PharmD (Emailed: 6/25/2019) (Updated: 4/13/2013)
Click here to contact Bryan Hayes, PharmD

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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Category: Orthopedics

Title: Fulcrum test

Posted: 10/1/2017 by Brian Corwell, MD (Emailed: 6/25/2019) (Updated: 6/25/2019)
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https://www.physio-pedia.com/Fulcrum_Test


Category: Orthopedics

Title: Morel-Lavall e lesion

Posted: 10/1/2017 by Brian Corwell, MD (Emailed: 6/25/2019) (Updated: 6/25/2019)
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https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4126145/