UMEM Educational Pearls

Category: Orthopedics

Title: Exercise-induced laryngeal obstruction (EILO)

Keywords: bronchospasm, asthma, exercise-induced laryngeal obstruction (PubMed Search)

Posted: 11/23/2013 by Brian Corwell, MD
Click here to contact Brian Corwell, MD

Unexplained respiratory symptoms during exercise are often incorrectly considered secondary to exercise induced asthma/bronchospasm.

An important diagnosis on the differential should be exercise-induced laryngeal obstruction (EILO).

Of 91 athletes referred for asthma workup, 35% had EILO.

The presence of inspiratory symptoms did not differentiate athletes with and without EILO.

61% of athletes with EILO used regular asthma medication at referral.

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Category: Pediatrics

Title: Can kids survive traumatic cardiac arrest? (submitted by Nikki Alworth, MD)

Keywords: trauma, cardiac arrest, return of spontaneous circulation (PubMed Search)

Posted: 11/22/2013 by Mimi Lu, MD
Click here to contact Mimi Lu, MD

Pediatric traumatic arrest victims have a very low survival rate. Previous studies have shown that 21% achieve initial ROSC but only 0.3% survive hospital discharge with an intact neurologic status.

A recent retrospective study examined predictors of survival for pediatric traumatic out-of-hospital cardiac arrest. Of the 362 patients included in the study, none had spontaneous circulation upon arrival in ED. BLS was initiated by EMS in the field with a mean response time of 5.4 minutes and mean transport time of 10.2 minutes. The study compared MAP, cardiac rhythm, urine output, skin color of face/trunk, initial GCS and body temperature.

In this study, 9% of kids made it to discharge, 11 of which had good neurologic outcome and 23 with poor neurologic outcome. Predictors of survival were:
  • High or normal BP
  • Normal heart rate after ROSC
  • Sinus rhythm after ROSC
  • Urine output >1 ml/kg/hr
  • Noncyanotic skin color
  • GCS >7 on arrival
Limitations of study: Very few kids survive with good neurologic outcome, making it difficult to identify accurate predictors for this group as the sample size is too small. Further, this study didn't look at hypothermia or ECMO as a means to achieve improved outcome.

Reference: Predictors of survival and neurologic outcomes in children with traumatic out-of-hospital cardiac arrest during the early postresuscitative period. Lin YR, Wu HP, Chen WL, et al. Journal Trauma Acute Care Surg. Sept 2013:75(3);439-447.


Category: Toxicology

Title: aPCC for rivaroxaban and dabigatran

Keywords: rivaroxaban, dabigatran (PubMed Search)

Posted: 11/21/2013 by Fermin Barrueto (Updated: 11/10/2024)
Click here to contact Fermin Barrueto

Reversal of the new anticoagulants rivaroxaban (Xarelto) and dabigatran (Pradaxa) has been challenging particularly in the ED setting with no definitive reversal agent. Intracerebral hemorrhage or critical GI bleed management becomes challenging and worsens mortality.

There is growing literature that states activated prothrombin complex concentrate or non-activated PCC may reverse these new anticoagulants. A volunteer study (1) showed its efficacy and concensus workgroups are now recommending aPCC as first line therapy(2).  The search goes on for a reliable reversal agent for these new anticoagulants which were suppose to solve more problems instead of create new ones.

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Category: International EM

Title: Meningococcal Outbreaks and Vaccine Coverage

Keywords: meningoccocus, Neisseria meningitidis, global, infectious disease (PubMed Search)

Posted: 11/20/2013 by Andrea Tenner, MD (Updated: 11/10/2024)
Click here to contact Andrea Tenner, MD

General Information:

Nisseria meningitidis is the common culprit in epidemic meningitis.  Serogroup B is currently causing an outbreak on the Princeton campus.  So what are the serogroups and why are they important?

Six main serogroups cause disease:  A, B, C, Y, X, W-135.

  • A: most common cause of meningitis in the Meningitis Belt in Sub-Saharan Africa, caused pandemics in the 1960s-1980s in Asia as well
  • B, C, Y: Cause the large majority of cases in Europe and the Americas
  • A, W-135: most common culprits in outbreaks of meningitis associated with the Hajj
  • X: causes disease in some countries in Sub-Saharan Africa

Two quadrivalent vaccines are currently licensed in the US that cover Serogroups A, C, Y, and W-135.

Relevance to the EM Physician: The currently available vaccines in the US cover the majority of serogroups of meningococcus, however, Serogroup B (currently causing an outbreak at Princeton) is not covered, nor is Serogroup X (for travelers to Sub-Saharan Africa).

Bottom Line: Serogroups B and X are not covered by the currently available vaccines in the US and at risk populations (and physicians treating those patients) should be made aware of the gap in coverage.  Investigations for a vaccine for Serogroup B (licensed in Europe and Australia, but not in the US) are currently underway.

University of Maryland Section of Global Emergency Health

Author: Andi Tenner, MD, MPH, FACEP

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Category: Critical Care

Title: Ottawa Rules for Subarachnoid Hemmorhage (SAH)

Keywords: subarachnoid hemmorhage, sah (PubMed Search)

Posted: 11/19/2013 by Feras Khan, MD (Updated: 11/10/2024)
Click here to contact Feras Khan, MD

Ottawa Rules for Subarachnoid Hemmorhage (SAH)

Background

  • Headache is a common reason for ER visits
  • 1-3% of headaches are SAH
  • Misdiagnosis of SAH can be fatal
  • Lumbar puncture can be a painful/time-consuming procedure
  • Goal is to design a decision rule to help guide the clinician

Design

  • Multi-center study at ten Canadian emergency departments.
  • 2131 adults with a headache peaking within 1 hour and no neurologic deficits
  • Non-traumatic headaches only; GCS of 15 required
  • SAH defined as: 1. CT evidence of SAH; 2. Xanthochromia in CSF; or 3. RBCs in the final tube of CSF, WITH positive angiography findings.

Results

132 (6.2%) had SAH

Decision rule including any:

  1. age 40 years or older
  2. neck pain or stiffness
  3. witnessed LOC
  4. onset during exertion

Had 98.5% sensitivity (95% CI, 94.6%-99.6%) and 27.5% specificity (95% CI, 25.6%-29.5%)

Adding “thunder-clap” headache and “limited neck flexion on examination” (inability to touch chin to chest or raise the head 8cm off the bed if supine) resulted in 100% (95% CI, 97.2%-100%) sensitivity.

The rule was then evaluated using a bootstrap analysis on old cohort data to validate the rule.

Conclusion/Limitations

  • Exciting new rule for SAH that needs to be validated in a new, independent cohort
  • The rule may not decrease the rate of investigation (CT, LP, or both)
  • It may decrease the amount of SAH that are missed on first visit to the ER
  • Limited by narrow criteria for inclusion in the rule/not meant for other causes of headache
  • See the JAMA editorial with the article for a nice discussion of the difficulties with decision making rules.
  • The rule:
    The Ottawa SAH Rule
    • For alert patients older than 15 y with new severe nontraumatic headache reaching maximum intensity within 1 h

    • Not for patients with new neurologic deficits, previous aneurysms, SAH, brain tumors, or history of recurrent headaches (≥3 episodes over the course of ≥6 mo)

    • Investigate if ≥1 high-risk variables present:

    1. Age ≥40 y

    2. Neck pain or stiffness

    3. Witnessed loss of consciousness

    4. Onset during exertion

    5. Thunderclap headache (instantly peaking pain)

    6. Limited neck flexion on examination

     

 

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Attachments

1311191832_ottawa_editorial.pdf (109 Kb)



Question

48 year-old presents after falling 15 feet following a “misunderstanding” with police. What's the diagnosis? ...and for a bonus question, why is this called a “Lover’s Fracture”? 

 

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Category: Cardiology

Title: Utility of Intra-Aortic Balloon Pump

Keywords: Intra-Aortic Balloon Pump, Cardiogenic Shock (PubMed Search)

Posted: 11/15/2013 by Semhar Tewelde, MD (Emailed: 11/17/2013) (Updated: 11/17/2013)
Click here to contact Semhar Tewelde, MD

Utility of Intra-Aortic Balloon Pump (IABP)

  • IABP therapy has not been proven to reduce mortality in all-comers with cardiogenic shock complicating acute myocardial infarction (IABP-SHOCK II)
  • A recent retrospective review of IABP therapy in patients with mechanical complications (ventricular septal rupture [VSR] or mitral regurgitation [MR]) following acute myocardial infarction has proven efficacious in this subset
    • IABP reduced mortality in patient with shock (61% vs 100%, p = 0.04)
    • IABP reduced preoperative mortality (11% vs 88%, p <0.001)
  • Post infarction VSR or MR with signs of cardiogenic shock should be considered for an IABP as a bridge to emergent surgical repair
  • Patients with mechanical complications without shock were not shown to benefit from an IABP and should undergo cardiac surgery after medical stabilization

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Category: Orthopedics

Title: Compartment Syndrome

Keywords: Compartment Syndrome (PubMed Search)

Posted: 11/16/2013 by Michael Bond, MD (Updated: 11/10/2024)
Click here to contact Michael Bond, MD

Compartment Syndrome

Compartment syndrome is classically described as having the 6 Ps:

  • Pain out of proportion to what is expected
  • Pulselessness [Late finding that you hope to never see]
  • Paresthesia
  • Paralysis
  • Pallor
  • Pressure


The diagnosis of compartment syndrome can be difficult but ultimately it comes down to measuring the pressures in the area of concern.  Various recommendations of the allowed pressure can be found, but in general a fasciotomy is not needed if the compartment pressure is 30 mmHg less then the diastolic pressure (The Delta 30).  So if the patients diastolic pressure is 70, a fasciotomy is not need if the compartment pressure is less then 40.  

Finally, if you are suspecting compartment pressure do NOT elevate the limb.  Leave it in a dependent position to help improve blood flow into the limb.



Category: Pediatrics

Title: Abdominal pain and fever

Keywords: Intussusception, abdominal pain, fever (PubMed Search)

Posted: 11/10/2013 by Jenny Guyther, MD (Emailed: 11/15/2013) (Updated: 11/16/2013)
Click here to contact Jenny Guyther, MD

Question

Case: A 3 year 9 month female presents with fever to 39.4 C and intermittent abdominal pain worsening over 2 days.  The patient had been tolerating food and had no change in her bowel habits.  Based on the imaging below, what is your diagnosis and treatment?

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Attachments

1311100901_657139537.jpg (603 Kb)

1311100902_657148738.jpg (108 Kb)

1311100912_US_intususseption.jpg (3,893 Kb)



Category: Toxicology

Title: All Benzodiazepines are Metabolized by the Liver

Keywords: benzodiazepine, lorazepam, liver (PubMed Search)

Posted: 11/11/2013 by Bryan Hayes, PharmD (Emailed: 11/14/2013) (Updated: 11/14/2013)
Click here to contact Bryan Hayes, PharmD

All benzodiazepines are metabolized by the liver. Some are just metabolized by pathways that are less dependent on global liver function.

The ‘LOT’ drugs are metabolized by conjugation, have no active metabolites, and have minimially affected half-lives even in the setting of liver disease.

  • L – Lorazepam

  • O – Oxazepam

  • T – Temazepam

The rest of the benzodiazepines are primarily metabolized via hepatic CYP-mediated oxidation and may have prolonged duration of effect in patients with marked liver impairment.

For a bit more detail and commentary by Dr. David Juurlink, please read my recent post on the Academic Life in Emergency Medicine blog: http://academiclifeinem.com/all-benzodiazepines-are-metabolized-by-the-liver/

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Helicopter EMS (HEMS) has rapidly grown over the past 30 years.  HEMS is frequently used to transport trauma patients from the scene of a crash. The question is: for which trauma patients is HEMS most useful?

A recent article published in the Journal of the American Medical Association, based upon data from the National Trauma Data Bank (NTDB), looked at injured patients transported to a trauma center by helicopter versus ground ambulance.  It showed that, after controlling for multiple known confounders, more severely injured patients had better outcomes when transported by helicopter than when transported by ground ambulances.  Another recent article in the Journal of Trauma and Acute Care Surgery, again based upon the NTDB further showed that HEMS survival benefit seems to limited to individuals with physiologic instability.

Bottom Line:

Transport of severely injured trauma patients by helicopter versus ground from the scene of injury to a trauma center improved patient outcomes and decreased mortality.  Transportation of stable, less injured patients by helicopter may actually worsen outcomes.

University of Maryland Section of Global Emergency Health

Author: Jon Mark Hirshon

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Acalculous Cholecystitis in the Critically Ill

  • Acute acalculous cholecystitis (AAC) accounts for almost 50% of cases of acute cholecystitis in the critically ill ICU patient.
  • Importantly, the mortality rate for AAC can be as high as 50%.
  • Risk factors for AAC include:
    • CHF
    • Cardiac arrest
    • DM
    • ESRD on hemodialysis
    • Postoperative
    • Burns
  • Unfortunately, the physical exam is unreliable, especially in intubated and sedated patients.
  • Furthermore, less than half of patients with AAC are febrile or have a leukocytosis.  LFTs can also be normal in up to 20% of patients.
  • Ultrasound remains the most common imaging modality for diagnosis.
  • Take Home Point: Consider AAC in the septic critically ill patient without a source.

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Question

28 year-old cachectic female presents in respiratory distress and is immediately intubated on arrival to Emergency Department. What's the diagnosis and what are some potential etiologies?

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Category: Cardiology

Title: Diagnosis of STEMI in LBBB

Keywords: AMI, LBBB, Sgarbossa criteria (PubMed Search)

Posted: 11/9/2013 by Ali Farzad, MD (Emailed: 11/10/2013) (Updated: 3/10/2014)
Click here to contact Ali Farzad, MD

Diagnosis of STEMI in patients with LBBB can be challenging. Guidelines that previously recommended emergent reperfusion for these patients have been reconsidered to avoid inappropriate cath lab activation and fibrinolytic therapy.

The 2013 ACC/AHA STEMI guidelines no longer consider new or presumably new LBBB a STEMI equivalent. This dramatic change may prevent inappropriate therapy for some, but fail to help identify patients with LBBB who are having STEMI's. Delayed reperfusion in this population could be fatal and is estimated to affect 5,000-10,000 patients per year in the US alone.

The Sgarbossa ECG criteria are the most validated tool to aid in the diagnosis of STEMI in the presence of LBBB. A Sgarbossa score of ≥ 3 has high specificity (>98%) and positive predictive value for acute MI and angiography-confirmed coronary occlusion. The following algorithm has been recently proposed to identify the high-risk population in which reperfusion therapy would be denied by the 2013 STEMI guidelines.

Watch this video to review Sgarbossa criteria and the modified Sgarbossa rule.

 

Want more emergency cardiology pearls? Follow me @alifarzadmd

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Attachments

1311092043_American_Heart_Journal_2013_MD.pdf (726 Kb)



Category: Orthopedics

Title: Cauda Equina

Keywords: back pain, cauda equina (PubMed Search)

Posted: 11/4/2013 by Brian Corwell, MD (Emailed: 11/9/2013) (Updated: 11/9/2013)
Click here to contact Brian Corwell, MD

Cauda equina syndrome results from compression of multiple lumbar and sacral nerve roots

Causes: Central disc herniation, spinal epidural abscess, malignancy, trauma, hematoma.

Consider this entity in those with back pain and radiculopathy at multiple spinal levels

Urinary retention occurs in >90% of patients

Saddle anesthesia occurs in 75%

Decreased rectal sphincter tone occurs in 60 to 80%

A post void residual volume <100 mL makes this entity very unlikely



Category: Pharmacology & Therapeutics

Title: Cephalosporin Side Chains and Allergies

Keywords: Cephalosporin,penicillin,anaphylaxis,urticaria,cross sensitivity (PubMed Search)

Posted: 11/7/2013 by Ellen Lemkin, MD, PharmD (Updated: 11/10/2024)
Click here to contact Ellen Lemkin, MD, PharmD

When patients with severe allergies to penicillin (urticarial, bronchospasm, anaphylaxis, angioedema) are excluded, the cross reactivity to cephalosporins is very low (approximately 0.1%)

The reaction is related to structures in the side chain, not the cyclical structure as thought in the past.

There are several cephalosporins with IDENTICAL side chains that should not be given to patients with allergies to specific penicillins, namely:

  • Penicillin:   do not give cefoxitin
  • Ampicillin:   do not give cefaclor or cephalexin
  • Amoxicillin: do not give cefadroxil or cefprozil

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Category: International EM

Title: Isolation criteria for MERS-CoV

Keywords: MERS-CoV, Viral Illness, Respiratory (PubMed Search)

Posted: 11/6/2013 by Andrea Tenner, MD
Click here to contact Andrea Tenner, MD

Case Presentation:

A 56y/o man with diabetes presents with fever, cough, and diarrhea x 2 days. 

V/S: T:38.7 BP:165/88 P: 105 R:24 O2 sat:91% on room air

CXR: left lower lobe infiltrate. 

On further history you learn he has just returned from visiting family in Saudi Arabia 7 days ago.  While there, he visited a cousin that was ill. 

 

Clinical Question:

Should this patient be isolated for Middle Eastern Respiratory Syndrome – Corona Virus (MERS-CoV)?

 

Answer:

Yes, there are 150 cases to date and 64 have died.  None confirmed in the US yet but 6 confirmed in Europe.

 

Patients who should be isolated in an airborne iso room with N95 mask use (similar to TB) are:

Patients with fever + pneumonia/ARDS AND one of the following:

  • Travel to the Arabian Peninsula within 14 days of symptom onset
  • Close contact with a person with fever and respiratory illness within 14 days of travel to the Arabian Peninsula
  • Member of a cluster of patients with severe ARI being evaluated for MERS-CoV

 

Bottom Line:

In patients with febrile respiratory illness requiring hospitalization and recent travel to the Arabian Peninsula: isolate for MERS-CoV and contact the health department.

 

University of Maryland Section of Global Emergency Health

Author: Jenny Reifel Saltzberg

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Category: Critical Care

Title: Ineffective Triggering - The Most Common Vent Dyssynchrony

Keywords: Mechanical ventilation, Critical Care, Intubation (PubMed Search)

Posted: 10/29/2013 by John Greenwood, MD (Emailed: 11/5/2013) (Updated: 11/5/2013)
Click here to contact John Greenwood, MD

 

Ineffective triggering is the most common type of ventilator dyssynchrony.  The differential diagnosis includes:

  • Auto peep (the most common cause) 
  • Neuromuscular weakness 
  • Improper ventilator settings

Auto peep is the most common cause of ineffective triggering and will often occur as a patient cannot create enough inspiratory force to overcome their own intrinsic peep (PEEPi).  Patients who are severely tachypnic or those with obstructive lung disease are at high risk for auto peep (not enough time to exhale).

Ineffective triggering can also occur if the patient cannot create enough of a negative inspiratory force to trigger the vent to deliver a positive pressure breath. Prolonged period of mechanical ventilation, over sedation, high cervical spine injuries, or diaphragmatic weakness are common causes.

Lastly, improper trigger sensitivities may make it difficulty for the ventilator to sense when the patient is attempting to take a spontaneous breath.  

For an example of a patient with ineffective triggering, check out: http://marylandccproject.org/2013/10/28/vent-problems1/

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Question

This week's visual pearl reviews the structures of the heart when being viewed in a parasternal long-axis view. What do the labels correspond to in the clip below (note: "E" and "F" are valves) and do you see any obvious abnormalities?  

 

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Secondary Prevention in AMI

Just as aspirin is pivotal in the treatment of acute coronary syndrome, medications such as beta-blocker, statins, and angiotensin-converting enzyme inhibitors have been proven to be essential in secondary prevention of AMI.

Patients after AMI are typically discharged on appropriate secondary prevention medications; however the prescribed doses are often far below the proven efficacy based on clinical trials.

A review of 6,748 patients from 31 hospitals enrolled in 2 U.S. registries (2003 to 2008) illustrated that only 1 in 3 patients were prescribed these medications at goal doses.

Of patients not discharged on goal doses, up-titration during follow-up occurred infrequently ~25%.

Optimal medication dosing and appropriate titration is integral to prevention of further morbidity and mortality.

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