UMEM Educational Pearls

Some quick board review pearls.  Remember these fractures/dislocations and the neurologic injury that is associated with them

  • Acetabular fracture – sciatic nerve
  • Anterior shoulder dislocation – axillary and musculocutaneous nerve
  • Elbow dislocation – ulnar or median nerve
  • Hip dislocation
    • Anterior – femoral nerve
    • Posterior – sciatic nerve
  • Humerus – radial nerve
  • Knee Dislocation – peroneal or tibial nerve
  • Olecranon fracture – ulnar nerve
  • Supracondylar fracture – median, radial or ulnar nerve
  • Tibia plateau fracture – peroneal nerve


Title: Transfusion guidelines

Category: Pediatrics

Keywords: transfusion, anemia, hemoglobin (PubMed Search)

Posted: 4/20/2012 by Mimi Lu, MD
Click here to contact Mimi Lu, MD

Children are at higher risk for complications related to the transfusion of blood products compared with adults. So when should we consider transfusion?

 

Normal hemoglobin values:

- highest at birth (14 - 24 g/dL),

- decreasing to 8 to 14 g/dL at 3 months,

- increasing to 10 to 14 g/dL at age 6 months to 6 years, 11 to 16 g/dL at age 7 to 12 years, and 11.5 to 18 g/dL in adulthood.

- Although the number of platelets are in the normal range at birth, their function is impaired.

 

For infants younger than 4 months, thresholds for red blood cell transfusions:

- hemoglobin levels are 12 g/dL for preterm infants or term infants born anemic,

- 11 g/dL for chronic oxygen dependency,

- 12 to 14 g/dL for severe pulmonary disease,

- 7 g/dL for late anemia in a stable infant,

- 12 g/dL for acute blood loss exceeding 10% of estimated blood volume.

 

For infants older than 4 months, thresholds for red blood cell transfusions:

- hemoglobin levels are 7 g/dL in a stable infant,

- 7 to 8 g/dL in a critically unwell infant or child,

- 8 g/dL in an infant or child with perioperative bleeding,

- 9 g/dL in an infant or child with cyanotic congenital heart disease (increased oxygen demand).

- 9 g/dl in children with thalassemia major (to slow bone marrow stimulation)

 

For children with sickle cell disease (SCD):

- threshold is 7 to 9 g/dL, or more than 9 g/dL if the child has previously had a stroke.

- perioperatively for major surgery: 9 to 11 g/dL, and sickle hemoglobin should be less than 30%, or less than 20% for thoracic or neurosurgery.

 

Bottom line:

A threshold of 7 g/dL is indicated for the transfusion of packed red blood cells in most children.

 

 

Reference:

1) Transfusion guidelines in children. Anasethesia and Intensive Care Medicine. 2012;13(1);20–23.

2) Medscape clinical education briefs



Cuff Pressures and the Prevention of VAP

  • As highlighted in a recent pearl, ventilator-associated pneumonia (VAP) is the second most common nosocomial infection in the US and is associated with increases in ICU length of stay and mortality.
  • With increasing ED lengths of stay for many critically ill patients receiving mechanical ventilation, measures to prevent VAP should be initiated in the ED.
  • In addition to elevating the head of the bed to 30-45 degrees, another low cost intervention is the measurement of endotracheal tube cuff pressures.
  • Cuff pressures below 20 cm H2O increase the risk of VAP.
  • Measure cuff pressure within 4 hours of inflation and maintain between 20-30 cm H2O.

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Question

67 yo male presents with burning substernal chest pain; worse with meals and when supine. What's the diagnosis?


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Title: Chest pain after a negative stress test

Category: Cardiology

Keywords: coronary artery disease, acute coronary syndromes, stress test (PubMed Search)

Posted: 4/15/2012 by Amal Mattu, MD
Click here to contact Amal Mattu, MD

(from Dr. Semhar Tewelde)

Stress testing is one modality used to screen for CAD. The goal is to identify a fixed obstruction to coronary blood flow (typically plaque > 50%) such as in stable angina. However, in ACS, both USA and AMI, the underlying pathophysiology is plaque rupture (typically  plaque < 50%) and thrombus formation that may not have been significant enough to cause a positive stress test.

The use of a prior negative stress test to determine the disposition of ED chest pain patients is questionable. The history of present illness should dictate patient disposition. In one study 20.7% of patients presenting to the ED with a negative stress test within three years of presentation still had significant CAD defined as a positive cardiac markers, subsequent positive stress test of any type, cardiac catheterization requiring intervention, or death due to medical cardiac arrest within 30 days of ED presentation.

 

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Chronic exertional compartment syndrome (CECS)

An overuse injury common in young endurance athletes

In athletes with lower leg pain, CECS was found to be the cause in 13.9% - 33%.

*This is likely under diagnosed as most recreation athletes will discontinue or modify their activity level at early symptom onset

Common in runners and most often involves the anterior compartment

Occurs due to increased pressure within the fascial compartments, primarily in the lower leg

Symptoms are bilateral 85 - 95% of the time

Exercise increases blood flow to leg muscles which expand against tight surrounding noncompliant fascia. This, in turn, increases compartment pressures and eventually reduces blood flow which leads to ischemic pain. Pain usually begins within minutes of starting exercise and experienced athletes can often pinpoint the time/distance required for symptom onset.

Symptoms are primarily pain (tightness, cramping, squeezing) but may also include paresthesias and numbness. Symptoms gradually abate with cessation of activity.

Diagnosis:  Although some physicians’ make a clinical diagnosis based on Hx and exam, definitive diagnosis requires measurement of compartment pressures both at rest and post exercise.

Nonsurgical treatment: activity modification and rest

Surgical treatment: >80% success with anterior and lateral compartments vs. 50% with deep posterior compartment.



  • usually in preschool or early school-age children presenting with tea-colored urine
  • most commonly is postinfectious (following URI)
  • may also have periorbital edema and high blood pressure
  • UA shows blood, and microscopy shows RBC's and RBC casts
  • no definitive emergent treatment, but prognosis is usually good with resolution of symptoms over 8-10 weeks

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Title: Maternal Opioid Use and Breast-Fed Infants

Category: Toxicology

Keywords: Opioid, breastfeeding, breast milk, newborn, infant (PubMed Search)

Posted: 4/5/2012 by Bryan Hayes, PharmD (Updated: 4/12/2012)
Click here to contact Bryan Hayes, PharmD

Over the last few decades, the rate of breastfeeding has increased steadily in the developed countries of the world. During this time, opioid  use in the general population has steadily increased as well. Despite this, clinicians remain unclear whether opioid use is safe during breastfeeding.

A recent article reviewed the production of breast milk, the transfer of xenobiotics from blood to milk, the characteristics that alter xenobiotic breast-milk concentrations, and the evidence of specific common opioids and infant toxicity.
 
Conclusion: The short-term maternal use of prescription opioids is usually safe and infrequently presents a hazard to the newborn.
 
 
Bonus app suggestion:
Continuing with the theme of the week, here is a nifty, free tox app for the iPhone called Emergency Toxicology. It is rudimentary and pretty basic, but it is a good starting tool.
http://itunes.apple.com/us/app/emergency-toxicology/id504893108?mt=8
iPhone Screenshot 1

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Sepsis is one of the top 10 causes of death in the U.S. and its incidence is on the rise.

The financial burden of sepsis is also growing; it is estimated that between 2000 and 2005 the overall cost of ICU hospitalization rose from $56.6 billion to $81.7 billion per year with severe sepsis accounting for $16.7 billion.

Although we may not be able to immediately modify the incidence of community-acquired sepsis, hospital-acquired sepsis can be reduced; for example, many cases of nosocomial sepsis are associated with catheter blood stream infections secondary to central-lines.

There are several simple strategies to prevent catheter-related blood-stream infections:

  • Ensure proper hand hygiene prior to central-line insertion
  • Use maximum sterile procedures during insertion of central venous catheters
  • Use skin antiseptics and proper dressings at catheter insertion sites
  • Rapid discontinuation of central venous catheters once no longer needed

Remember: We play a large role in reducing nosocomial sepsis; be vigilant about your sterile techniques during central catheter insertions and question the need for every single line.

 

Bonus pearl (only for iPhone): MDRNTools is a FREE app (that’s right, FREE!) with lots of ED and ICU applications such as an IV med calculator, an RSI handbook, a Stroke Scale calculator, and more.

Download http://itunes.apple.com/us/app/mdrntools/id505794224?mt=8&ls=1

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Well, here is a cool little app that has recently been released. It's an app that can predict what a child's height will be as a mature adult. This is not a joke.

A free mobile application developed by the International Center for Limb Lengthening (ICLL) at the Rubin Institute for Advanced Orthopedics (RIAO) of Sinai Hospital (right in our very own Baltimore) can predict the future mature height and bone lengths of children with the input of basic information.

That's right people. The formula has amazing accuracy and has been studied in many different centers. It's supposedly 97%+ accurate in predicting height.

The Multiplier App, available for Android, iPhone and iPad devices, is based upon the Multiplier Method, a series of formulas used to calculate and predict height and bone length in children. These formulas were developed by a team that included members of the ICLL.

Here is what it looks like. Just click on "Height" (see enclosed jpg image of the app) and then type in the child's birthday and current height in either inches or cm. The formula will then calculate what there predicted height will be.

Very, very cool ( at least I think)


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Title: The Athlete's Heart Part II

Category: Cardiology

Keywords: athlete, ventricular hypertrophy (PubMed Search)

Posted: 4/8/2012 by Amal Mattu, MD
Click here to contact Amal Mattu, MD

(Pearl provided by Dr. Semhar Tewelde)

Physiological LV hypertrophy in trained athletes is defined by an isolated increase in QRS amplitude, normal axis, normal atrial and ventricular activations patterns, and normal ST-segment T-wave replorization; athletes of African/Caribbean descent have prominent cardiovascular remodeling leading to pronounced voltage criteria for LV hypertrophy and BER

Despite the presence of voltage criteria for LVH, pure QRS voltage criteria for LVH in an asymptomatic athlete without family hx of cardiovascular diseases or SCD, and lack of non-voltage ECG criteria does not warrant systematic evaluation with echocardiography.

In other words, young patients, especially men, especially those of African/Caribbean descent, will be expected to have large voltage QRS complexes and sometimes abnormal repolarization, and this is not necessarily a pathologic finding.

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Title: Medial Tibial Stress Syndrome

Category: Orthopedics

Keywords: stress fracture, shin splints (PubMed Search)

Posted: 4/7/2012 by Brian Corwell, MD (Updated: 11/24/2024)
Click here to contact Brian Corwell, MD

Exertional leg pain in the athlete carries a wide range of possible etiologies. In a recent review article, etiologies included, stress fracture (25%), exertional compartment syndrome (33%), medial tibial stress syndrome (13%), nerve entrapment (10%), and popliteal artery entrapment syndrome.

 

Medial Tibial Stress Syndrome (MTSS) is also known as shin splints. It is a repetitive-stress overuse injury.

Risk factors include: hyperpronation, higher BMI, increased hip internal rotation, and hyperplantar flexion.

While MTSS may be on a stress reaction spectrum that includes fracture, the causes are likely to also include tendinopathy and muscle dysfunction (tibialis anterior, posterior and soleus).

Radiographs will be normal with this condition. MRI and bone scan may show signal abnormality along the posterior medial tibial surface.

Treatment: In most cases participation in sports may continue. Also consider, rest/activity modification, ice, NSAIDs, physical therapy for calf stretching and strengthening,  and rigid orthotics (to correct foot hyperpronation). Semi rigid and neoprene orthotics may be considered for prevention in those with a prior history.



Title: Fidaxomicin vs. Vancomycin for Clostridium difficile infection

Category: Pharmacology & Therapeutics

Keywords: vancomycin, c. diff, clostridium difficile, fidaxomicin (PubMed Search)

Posted: 4/4/2012 by Bryan Hayes, PharmD (Updated: 4/7/2012)
Click here to contact Bryan Hayes, PharmD

In a recent  multicenter, double-blind, randomized, non-inferiority trial, vancomycin was compared to fidaxomixin for Clostridium difficile infection.

  • Location: 45 sites in Europe and 41 sites in the USA and Canada

  • Patients: Age 16 years or older with acute toxin-positive C difficile infection.

  • Treatment: Oral fidaxomicin (200 mg every 12 h) or oral vancomycin (125 mg every 6 h) for 10 days.

  • Endpoint: Clinical cure, defined as resolution of diarrhea and no further need for treatment. 

  • Results: 198 (91.7%) of 216 patients in the per-protocol population given fidaxomicin achieved clinical cure, compared with 213 (90.6%) of 235 given vancomycin (one-sided 97·5% CI -4·3%). Occurrence of treatment-emergent adverse events did not differ between groups. 

  • Author conclusions: Fidaxomicin could be an alternative treatment for infection with C difficile, with similar efficacy and safety to vancomycin.

  • Funding: Optimer Pharmaceuticals.

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It is likely that during ones career in Emergency Medicine, one will be faced with how to work up a child presenting to the ER following exposure to common house electrical current.  The older recommendations were such that all children exposed, received a screening EKG and were admitted to telemetry for monitoring.  However, a relatively recent article in the Annals of Emergency Medicine suggests otherwise.

In fact, after reviewing several studies the authors conclude that, although there is not enough literature to support evidence based practice “guidelines”, there appears to enough evidence to support that practice of “safely discharging these children without an initial EKG evaluation or inpatient cardiac monitoring after a common household current exposure.” This includes both 120V and 220 V exposures.

Clearly, some patients may require work up and/or admission based on other injuries or clinical presentation.

 

References:
Chen E H, Sareen A, Do Children Require ECG Evaluation and Inpatient Telemetry After Household Electrical Exposures? Ann Emerg Med. 2007;49:64-67.



Protamine for enoxaparin overdose

  • Protamine may be used to treat severe cases of hemorrhage in enoxaparin overdose
  • Protamine reverses the prolonged aPTT, but fails to completely reverse the anti-Xa effect (reverses about 60%)
  • Administer protamine by slow IV to equal the dose of enoxaparin injected: (1:1 ratio) 
  • if < 8 hours after last dose enoxaparin, give 1 mg protamine per 1 mg enoxaparin;
  • if 8-12 hours after last dose enoxaparin, give 0.5 mg protamine per 1 mg enoxaparin;
  • if >12 hours after last dose of enoxaparin,  protamine is not required


Transferring Multidrug-Resistant Organisms

  • Hospital-associated infections are a major cause of morbidity and mortality, especially among the critically ill.
  • Worldwide, the emergence of multidrug-resistant (MDR) bacteria has caused significant problems.
  • A recent study from the University of Maryland examined the impact of environmental contamination on the rate of transfer of MDR bacteria to healthcare workers clothing.
  • Two important findings from this study of ICU patients were:
    • Up to 8% of healthcare workers entered a patient's room with MDR bacteria on their hands
    • Almost 5% of healthcare workers had MDR bacteria (most notably Acinetobacter) on their hands upon exiting the room despite using gloves and a gown
  • Take Home Point: Be sure to use hand hygiene upon entering and exiting a patient's room who is colonized with MDR bacteria!

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Title: the athlete's heart and ECGs

Category: Cardiology

Keywords: athlete, electrocardiogram, electrocardiography (PubMed Search)

Posted: 4/1/2012 by Amal Mattu, MD (Updated: 11/24/2024)
Click here to contact Amal Mattu, MD

Pearl provided by Dr. Semhar Tewelde

The Athlete's Heart and ECG Abnormalities
Up to 80% of athletes have common training related ECG changes/abnormalities including: sinus bradycardia, asymptomatic sinus pause, sinus arrhythmia, first degree AV block, incomplete right bundle branch block, benign early repolarization (BER), and isolated QRS voltage criteria for left ventricular (LV) hypertrophy.

Approximately 5% athletes exhibit uncommon training unrelated ECG changes/abnormalities including: T-wave inversions, ST-depression, pathological Q-waves, left axis deviation/left anterior fasicular block, right axis deviation/left posterior fasicular block, right ventricular hypertrophy, complete left or right bundle branch block, long or short QT interval, ventricular pre-excitation/WPW, Brugada pattern, and arrhythmogenic right ventricular dysplasia (ARVD).

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Title: Paroxysmal Torticollis of Infancy

Category: Pediatrics

Posted: 3/31/2012 by Rose Chasm, MD (Updated: 11/24/2024)
Click here to contact Rose Chasm, MD

  • both head tilting to one side and rotation of the chin toward the other side
  • develops during infancy with episodes that last for hours to days
  • idiopathic neurologic condition which wanes after 2 years and stops by 3 years
  • mild delays in fine and gross motor skills are common along with family history of migraines
  • no accepted medical treatment or therapy
  • must have a normal physical and neurological examination that does not include abnormal/assymetric muscle tone, abnormal eye movements, or cranial nerve palsy

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Title: Nebulized epinephrine for Smoke Inhalation

Category: Toxicology

Keywords: epinephrine, carbon monoxide, smoke inhalation (PubMed Search)

Posted: 3/29/2012 by Fermin Barrueto (Updated: 11/24/2024)
Click here to contact Fermin Barrueto

Animal studies can pave the way for new clinical treatment modalities. In the setting of lung injury due to smoke inhalation, one of the problems (if you can get the ET tube in) are the elevated ventilatory pressures due to the massive edema. In this sheep model of smoke inhalation, nebulized epinephrine improved ventilatory pressures, PaO2/FiO2 ratio and pulmonary shunting.

We may have these sheep to thank for this new treatment.

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Title: Want more apnea time during Rapid Sequence Intubation? Raise the head of the bed.

Category: Critical Care

Keywords: apnea time, rapid sequence intubation, atelectasis, crticial care, intubation, hypoexemia, obesity (PubMed Search)

Posted: 3/26/2012 by Haney Mallemat, MD (Updated: 3/27/2012)
Click here to contact Haney Mallemat, MD

The supine position during rapid sequence intubation may result in posterior lung atelectasis thereby reducing lung volumes, oxygenation reserve, and ultimately apnea time.

Several studies have shown that elevating the head of the bed by at least 20 degrees or placing a patient in reverse Trendelenberg position (for patients with contra-indications to elevating the head of the bed) during RSI may significantly increase apnea time.

Elevating the head of the bed may be especially helpful for patients with BMIs >35

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