UMEM Educational Pearls - By Haney Mallemat

Category: Critical Care

Title: Heat Stroke? Time to Chill.

Keywords: heat stroke, critical care, acute kidney injury, seizures, neurological (PubMed Search)

Posted: 7/19/2011 by Haney Mallemat, MD
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Heat stroke is hyperthermia (>41.6 Celsius / 106 Fahrenheit) plus neurologic findings (e.g., altered mental status, seizures, coma, etc.); it also causes systemic inflammation response syndrome (i.e., cytokine release), coagulation disorders (e.g., thrombosis in end organs) and tissue abnormalities (e.g., acute kidney injury and rhabdomyolysis)

Two classifications exist:

  • Exertional heatstroke (young people engaged in strenuous physical activities in hot climates)
  • Non-exertional heatstroke occurring in sedentary people (elderly, debilitated, or chronically-ill patients) who are unprotected from the elements (e.g., trapped in apartments during heat waves)

Treatment includes:

  • Insertion of a continuous core thermometer
  • Supporting ABC’s
  • Cooling by at least to 0.2 degrees celsius per minute to 39 degrees (to avoid overshoot)
  • Benzodiazepines for sedation, shivering, and seizures
  • Antipyretics and phenytoin have not been shown beneficial
  • Support and protect end-organs with particular attention to kidneys; increased risk of kidney injury from rhabdomyolysis, ischemia and systemic inflammation.

Despite the most aggressive therapy, up to 30% survivors may have permanent neurologic or multi-organ system dysfunction months to years after recovery

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Category: Visual Diagnosis

Title: What's the Diagnosis? Written by Dr. Ari Kestler

Posted: 7/10/2011 by Haney Mallemat, MD (Emailed: 7/11/2011) (Updated: 8/28/2014)
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Question

48 year old male following 15 foot fall onto both feet. What is the diagnosis?
…and why is it called the “Lover’s Fracture”?
 

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Category: Airway Management

Title: Amiodarone and Thyroid Disease

Keywords: thyroid, hyperthyroid, hypothyroid, amiodarone (PubMed Search)

Posted: 7/5/2011 by Haney Mallemat, MD
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Amiodarone is a class III anti-arrhythmic for tachyarrhythmias

Although most patients remain euthyroid on amiodarone, 4-18% develop thyroid disease months to years after exposure.

Amiodarone-induced thyroid disease occurs because amiodarone is structurally similar to triiodothyronine and thyroxine and each 200mg tablet contains 75 mg of iodine.

Two types of amiodarone-induced thyroid disease:

  • Amiodarone-induced hypothyroidism (AIH)
  • Amiodarone-induced thyrotoxicosis (AIT)

Amiodarone-induced hypothyroidism (AIH)

  • Presents with subtle to overt hypothyroidism 
  • Treat by discontinuing amiodarone; thyroid recovers within 3 months
  • If amiodarone cannot be discontinued, start levothyroxine

Amiodarone-induced thyrotoxicosis (AIT)

  • Sudden symptom onset months to years following exposure; mean 2-47 months post-exposure
  • Can be a life-threatening presentation (similar to thyroid storm) with severe cardiac manifestations and hemodynamic instability
  • Treatment (treat like thyroid storm, if severe)
    • Discontinue drug, if possible
    • Thionamides (inhibit enzyme producing thyroid hormones)
    • Methimazole or propylthiouracil
    • Beta-blockers
    • Steroids
    • Airway and hemodynamic support

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Question

49 y.o. female on Trimethoprim/sulfamethoxazole presents with rash and oral mucus membrane lesions. Diagnosis?

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Category: Critical Care

Title: Cancer and Acute Kidney Injury (AKI)

Keywords: AKI, critical care, ICU, cancer, renal failure, acute kidney injury (PubMed Search)

Posted: 6/21/2011 by Haney Mallemat, MD
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Cancer patients admitted to ICUs with AKI or who develop AKI during their ICU stay have increased risk of morbidity and mortality. AKI in cancer patients is typically multi-factorial:

Causes indirectly related to malignancy

  • Septic, cardiogenic, or hypovolemic shock (most common)

  • Nephrotoxins:

    • Aminoglycosides

    • Contrast-induced nephropathy

    • Chemotherapy 

  • Hemolytic-Uremic Syndrome

Causes directly related to malignancy

  • Tumor-lysis syndrome

  • Disseminated Intravascular Coagulation

  • Obstruction of urinary tract by malignancy

  • Multiple Myeloma of the kidney

  • Hypercalcemia

Because AKI increases the already elevated morbidity and mortality in these patients, prevention (e.g., using low-osmolar IV contrast, avoiding nephrotoxins), early identification (e.g., strict attention to urine output and renal function), and aggressive treatment (e.g., early initiation of renal replacement therapy) is essential.

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Question

13 y.o. with shoulder trauma (during basketball game). Arm held in adduction and exquisite scapular tenderness. Diagnosis?

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Category: Critical Care

Title: Controlling uremic bleeding

Keywords: uremia, bleeding, ddavp, estrogens, epogen, cryoprecipitate (PubMed Search)

Posted: 6/6/2011 by Haney Mallemat, MD (Emailed: 6/7/2011) (Updated: 6/7/2011)
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Bleeding associated with uremia is a spectrum, from mild cases (e.g., bruising or prolonged bleeding from venipuncture) to life-threatening (e.g., GI or intracranial bleed). The exact pathologic mechanisms are not understood, but are likely multi-factorial (e.g., dysfunctional von Willebrand’s Factor (vWF) and factor VIII, increased NO, etc.)

Besides dialysis, treatments for uremic bleeding include:

  1. DDAVP (fastest)
    1. 0.3-0.4 micrograms/kg IV or SC
    2. Increases vWF and factor VIII release
    3. Advantages: Begins < 1 hour
    4. Disadvantages: Tachyphylaxis; Stored factors deplete
  2. Cryoprecipitate
    1. Replaces fibrinogen, vWF, and factor VIII
    2. Advantages: Works 1-4 hours
    3. Disadvantages: transfusion reactions, infections, pulmonary edema, etc.
  3. Conjugated Estrogens
    1. Unclear mechanism; possibly increases ADP and thromboxane activity
    2. 0.6 mg/kg once daily x 5 days
    3. Advantages: Short and long-term effects
    4. Disadvantages: Hot flashes (males too!)
  4. Recombinant Erythropoietin (slowest)
    1. 40-150 U/kg three times weekly
    2. Multiple mechanisms
    3. Advantages: Helps anemia (common in renal failure) as well as bleeding complications.
    4. Disadvantages: Up to 7 days to observe effects

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Question

13 y.o. female with ankle pain following fall down escalator. What's the diagnosis? (Hint: Look very closely)

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Category: Critical Care

Title: Typhlitis

Keywords: neutropenia, sepsis, abdominal pain, necrotizing enterocolitis (PubMed Search)

Posted: 5/23/2011 by Haney Mallemat, MD (Emailed: 5/24/2011) (Updated: 5/24/2011)
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  • Necrotizing enterocolitis with predilection for cecum.
  • Occurs in the immunosuppressed, especially when neutropenic (<500 PMNs)
  • Typically a polymicrobial infection; gram positive cocci, gram negative rods, anaerobes, and/or fungal. 
  • Classically, right lower quadrant pain but can present with diffuse abdominal pain and peritoneal signs.
  • CT scan with IV and PO contrast is diagnostic (see below)
  • Treatment:
    • Culture and begin broad spectrum antibiotics (cover anaerobes) and antifungals (if suspected) 
    • Aggressive resuscitation
    • Surgical consult for GI perforation or clinical deterioration
  • High mortality (40-50%)

TIP: Suspect when abdominal pain presents 10-14 after chemotherapy (when PMNs are lowest).

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Question

50 yo female s/p motor vehicle crash. Diagnosis?

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Category: Critical Care

Title: Treating Clostriudium difficile in the critically-ill

Keywords: Clostridium difficile, diarrhea, critical, ICU, sepsis, abdominal pain, vanocmycin,metronidazole, fidaxmicin (PubMed Search)

Posted: 5/10/2011 by Haney Mallemat, MD
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Although oral metronidazole is indicated for mild to moderate Clostridium difficile associated diarrhea, oral vancomycin should be considered first-line therapy in critically-ill patients with moderate to severe disease. Vancomycin dosing should begin at 125mg PO q6 and increased to 250mg q6 if poor enteral absorption exists. Consider adding metronidazole IV if either reduced enteral absorption or severe disease exists. 

Recently, fidaxomicin has been shown to be non-inferior to oral vancomycin in the treatment of mild to moderate C. difficile. While promising, the study population was not critically-ill and extrapolation should be avoided.

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Question

70 yo female from nursing home with fever. RUQ ultrasound is shown below. Diagnosis?

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Category: Critical Care

Title: Are Two Drugs Better Than One?

Keywords: sepsis, shock, antimicrobials, combination, antibiotics (PubMed Search)

Posted: 4/26/2011 by Haney Mallemat, MD
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A mortality benefit from combination antimicrobial therapy has not been clearly demonstrated in sepsis. However, when only the most severely-ill patients (i.e., septic shock) are considered in subgroup analysis, there appears to be a mortality benefit to using two antimicrobials against a suspected organism.

Combination antimicrobial therapy may reduce mortality through three mechanisms.

  1. Increased probability that the causative organism will respond to at least one drug. 
  2. Preventing emergence of antimicrobial resistance.
  3. Two antimicrobials may act synergistically.

Always obtain appropriate cultures before initiating therapy. Although identification and susceptibility of the organism may take some time, eventually narrowing antimicrobial therapy to monotherapy in the ICU is still recommended. 

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Question

Patient presents with the following X ray after yawning. Diagnosis?

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Category: Critical Care

Title: Vancomycin Alternatives

Keywords: Vancomycin, Daptomycin, Linezolid, MRSA, gram positive, infections, sepsis, pneumonia (PubMed Search)

Posted: 4/12/2011 by Haney Mallemat, MD
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Vancomycin is often started empirically for gram-positive and MRSA coverage. Although effective and generally well-tolerated, emerging resistance and side-effect profiles limit its use in some patients. Two alternatives are Linezolid and Daptomycin.

 

Linezolid

  • 600 mg IV every 12 hours
  • No renal dosing
  • Better lung penetration in pneumonia (compared to Vancomycin)
  • Side effects: Serotonin Syndrome (w/ concurrent MAOIs), hypersensitivity reaction, and myelosuppresssion

 

 

Daptomycin

  • 4 mg/kg IV once daily (skin/subcutaneous tissues infection), 6 mg/kg IV once daily (bacteremia or endocarditis), or 6-8mg/kg IV once daily (bacteremia with intravascular line)
  • Renally dosed by altering administration frequency; no change in dose.
  • NEVER use for pneumonia; pulmonary surfactant binds and inactivates drug.
  • Side effects: Reversible rhabdomyolysis (requires weekly CPK levels)

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Category: Visual Diagnosis

Title: What's the diagnosis? Written by John Greenwood, MD

Posted: 4/10/2011 by Haney Mallemat, MD (Emailed: 4/11/2011) (Updated: 4/11/2011)
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Question

60 y/o male transferred from local rehab facility c/o abdominal pain.

 

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Category: Critical Care

Title: Non-invasive Ventilation (NIV): What s the Evidence?

Keywords: bilevel ventilation, bipap, cpap, respiratory failure, respiratory distress, copd, acute pulmonary edema (PubMed Search)

Posted: 3/29/2011 by Haney Mallemat, MD
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Emergency Medicine physicians are gaining experience with non-invasive ventilation (i.e., Bi-level ventilation and continuous positive-pressure ventilation) in managing respiratory distress and failure. Although NIV is commonly used across a variety of pathologies, the best data exists for use with COPD exacerbation and cardiogenic pulmonary edema (CHF, not an acute MI) 

 

Although other indications for NIV have been studied, the data is less robust (eg., smaller study size, weak control groups, etc.). If there are no contraindications, however, many experts still support a trial of NIV in the following populations:

  • Asthma
  • Severe community acquired pneumonia
  • Acute lung injury / Acute Respiratory Distress Syndrome
  • Chest trauma (lung contusion, rib fractures, flail chest,etc)
  • Immunosuppression with acute respiratory failure
  • Neuromuscular respiratory failure (eg., Myesthenia Gravis)
  • Cystic Fibrosis
  • Pneumocystis Jiroveci Pneumonia
  • “Do not intubate” status

 

Failure to clinically improve during a NIV trial should prompt invasive mechanical ventilation.

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Category: Visual Diagnosis

Title: What's the diagnosis?

Posted: 3/27/2011 by Haney Mallemat, MD (Emailed: 3/28/2011) (Updated: 3/28/2011)
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Question

25 year old male presents after falling from 10 feet and landing on right shoulder. Diagnosis?

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Category: Critical Care

Title: Changes in pulmonary physiology during pregnancy

Keywords: pulmonary physiology, critical care, respiratory alkalosis (PubMed Search)

Posted: 3/15/2011 by Haney Mallemat, MD
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Many changes in pulmonary physiology occur during pregnancy. These changes are generally well tolerated but can become problematic when pathologic states arise.

Here are a few examples of the normal changes and potential consequences:

Progesterone increases tidal volume and respiratory rate.

  • “Normally" a mild respiratory alkalosis pH 7.4-7.47, PaCO2 28-32, and bicarbonate 17-22 (renal compensation).

  • Low metabolic reserve with systemic illness.

Weight gain, anasarca, and breast size reduces chest wall elasticity.

  • Potential for restrictive physiology and reduced lung volumes.

  • Can be challenging to to mechanically ventilate due to decreased compliance and intra-thoracic pressure 

Mechanical displacement of abdominal and thoracic contents by growing uterus.

  • Reduced lung volumes leading to reduced oxygen reserve and decreased apnea time.

  • Aim higher if placing chest tube (avoid abdominal contents)

  • Uterine pressure on stomach can increase aspiration risk and pulmonary injury. 

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Category: Visual Diagnosis

Title: What's the daignosis? Written by Sanober Shaikh, MD

Keywords: lung, ultrasound, pneumonia, hepatization, sonogram, air bronchograms (PubMed Search)

Posted: 3/13/2011 by Haney Mallemat, MD (Emailed: 3/14/2011)
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Question

 

65 yo female with breast cancer presents with dyspnea and CXR shown below. Diagnosis? Can anything help clarify the diagnosis? 

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