UMEM Educational Pearls

There is a growing recognition of patients who have a subtoxic acetaminophen level at the 4-hour mark, but then still go on to have a toxic level later.

This is concerning in that we usually can exclude the chance for toxicity if the 4-hour, post-ingestion level is < 150 mcg/mL following an acute ingestion (plotted on Rumack-Matthew nomogram).

It still is not clear exactly what subset of patients need to have a second level drawn, but a recurring theme seems to be ingestion of acetaminophen in combination with agents that slow GI motility, such as diphenhydramine or opioids. It may be worth ordering a second APAP level (possibly at 8 hours) in patients ingesting these prodcuts.

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Lung Protective Ventilator Settings Still Underutilized

• It's been over 10 years since the publication of the ARDSnet trial, which demonstrated an 8.8% absolute reduction in short-term mortality for patients with ARDS ventilated with "lung protective" settings (tidal volume 6 ml/kg, plateau pressure < 30 cm H20).
• A recent study in the BMJ evaluated the association of these settings with 2-yr survival in patients with acute lung injury.
• The study, carried out in 13 ICUs from 4 academic hospitals in Baltimore, found some surprising results:
  • In patients whose ventilator settings were 100% compliant with lung protective settings, there was an 8% absolute reduction in mortality.
  • For each increase of 1 ml/kg above recommended tidal volume there was an 18% relative increase in mortality.
  • 37% of patients never received lung protective ventilation.
• Take home point: lung protective settings appear to confer not only short-term but also long-term mortality benefit for patients with acute lung injury, yet remain underutilized even in major academic centers.

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Question

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Takotsubo cardiomyopathy a.k.a. stress cardiomyopathy is an acute reversible disorder characterized by left ventricular (LV) dysfunction most commonly affecting postmenopausal women

The LV adopts the shape of an octopus trap (“takotsubo”) describing the narrow neck and broad base globular form during systole

Symptoms include precordial chest pain, dyspnea, or heart failure presenting with pulmonary edema mimicking ACS

Mayo Clinic Diagnostic Criteria

 - Suspicion of AMI based on symptoms and STEMI on ECG

 - Transient hypokinesia or akinesia of the middle and apical regions of LV

 - Functional hyperkinesia of the basal region of LV

 - Normal coronary arteries (luminal narrowing <50%)

 - Absence of recent head injury, ICH, HCOM, myocarditis, or pheochromocytoma

Treatment is symptomatic and determined based on complications during the acute phase; occasionally requiring IABP or ECMO

Prognosis is better than those with ACS, however initial LVEF is similar to those seen with ischemic heart disease 

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A recent paper reviewed 53 articles to assess the utility of vasopressors in cardiac arrest. The authors aimed to determine if vasopressors improved ouctomes in this patient population. Here are their conclusions:

1. Epinephrine is associated with improvement in short term survival outcomes as compared to placebo, but no long-term survival benefit has been demonstrated.
2. Vasopressin is equivalent for use as an initial vasopressor when compared to epinephrine during resuscitation from cardiac arrest.
3. There is a short-term, but no long-term, survival benefit when using high dose vs. standard dose epinephrine during resuscitation from cardiac arrest.
4. There are no alternative vasopressors that provide a long-term survival benefit when compared to epinephrine.

Although these conclusions don't support the use of vasopressors in cardiac arrest, we should not abandon these therapies. Most of the trials were completed before wide-spread recognition of the post-cardiac arrest syndrome, implementation of therapeutic hypothermia protocols, and early cardiac catheterization.

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Henoch-Schonlein Purpura (aka. Anaphylactoid purpura) is a small vessel vasculitis.

Background:

• most commonly diagnosed vasculitide in childhood
• age range 3-15 years, mean age 4yo, mostly <7yo (75% cases)
• more cases in Winter and Spring months
• boys more commonly than girls (2:1)
• IgA-mediated leukoclastic vasculitis

Clinical Features:

• Rash: progresses to petechiae, purpura; occurs on lower extremities and buttocks in dependent areas
• Joints: arthritis/arthralgia mainly of large joints (knees, ankles)
• GI: colicky abdominal pain, may occur with melena (33%) or less likely, hematemesis; ultrasound for intussusception (2-14%)
• Renal: microscopic hematuria with/without proteinuria; usually transient but may lead to progressive renal disease in patients with more severe, persistent symptoms
• Orchitis and/or angioedema may also occur

Etiology:

• unknown
• preceding URI (50%)
• associated with bacteria (Strep pyogenes, Legionella, Mycoplasma), viruses (EBV, CMV, parvovirus), drugs (penicillin, cephalosporins), and insect bites

Diagnosis:

• clinical features
• lab studies that are helpful but nonspecific: high WBC, high ESR, high IgA, normal platelet and coagulation studies

Treatment:

• supportive care, may last up to 4 weeks
• steroids may be helpful but evidence has not shown true benefit
• recurrence happens in 40% of cases

Acute, uncomplicated cystitis (in the non-pregnant female):

·      The drug of choice is SMX/TMP (provided the resistance rate is <20%) X 3 days.

·      An alternative is nitrofurantoin X 5 days.

Acute, uncomplicated pyleonephritis (in the non-pregnanct female) may be treated with:

·      Levofloxacin X 5 days, or ciprofloxacin X 7 days (provided resistance rate is <10%).

·      Alternatively, SMX/TMP may be used X 14 days.

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Crystalloids (i.e., 0.9% saline and lactated ringers) have been used during resuscitation for more than a century. Their invention, however, was more accidental than intentional.

Crystalloids were first used during the European Cholera epidemic of 1831. Hartog Hamburger later modified this solution in 1896 to the solution we know today as "normal" saline. Hamburger's solution was only intended for in vitro study of RBC lysis and was never intended for clinical use.  

Around this time, Sydney Ringer was testing several fluids to use for physiologic studies. Ringer's lab assistant was erroneously substituting tap water for distilled water when preparing these solutions. Ringer later discovered that this tap water contained minerals making the solution "physiologic", isotonic, and safe for human use; Alexis Hartmann later added sodium lactate to create Ringer's Lactate. 

Since the invention of crystalloids, many types of resuscitation fluids have been created and studied (i.e., albumins, gelatins, and starches); all have been shown to be more expensive, with no more benefit, and with possibly more harm when compared to crystalloids. 

The "perfect" resuscitation fluid still alludes us today, but of all of the solutions marketed crystalloids are arguably the best...despite their accidental history.

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Question

25 year-old male was struck by a car while crossing the street. Chest X-ray and CT Chest with 3D reconstruction are shown below. What's the diagnosis? 

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Yamaguchi Cardiomyopathy

Yamaguchi cardiomyopathy a.k.a. apical hypertrophic cardiomyopathy (AHCM) was first described 1976 in Japanese patients.

AHCM is a variant of hypertrophic cardiomyopathy that is nonobstructive with predominant involvement of the apex of the heart.

AHCM is frequently misdiagnosed as ACS or STEMI since the typical ECG abnormalities include giant inverted T waves or ST elevation in the mid precordial leads, however coronaries are characteristically clean on cardiac catheterization.

Echocardiography classically used to diagnosis HCM may frequently miss AHCM because hypertrophy is only localized to the apex.

Nuclear magnetic resonance imaging or angiography reveals the pathognomonic "ace of spades" configuration of the left ventricle with systolic obliteration of the apical region.

Unlike HCM sudden cardiac death is very uncommon.

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Travel across time zones is regularly required of profession and collegiate athletes (in addition to the some of us professionally)

Jet lag is defined as insomnia or excessive daytime sleepiness/malaise following travel across at least 2 time zones

                Symptoms usually persist 1 day for each time zone crossed

The sleep schedule is primarily modulated by light and melatonin

Secretion of melatonin helps induce sleep

Exposure to light stimulates arousal and inhibits melatonin secretion

Who is at risk?

Those with more rigid sleep habits have more symptoms

“Morning” people have less difficulty flying eastward

“Evening” people have less difficulty flying west

However, overall, eastward travel causes the most severe symptoms which persist for up to 7 days (versus <3 days with westward travel)

                (The length of the day gets shortened and the circadian system must shorten to reestablish a normal rhythm. The human body demonstrates a natural tendency toward periods longer than 24 hours)

Those with higher levels of physical fitness adjust more quickly

Effects similar in men and women

Midday arrivals experience fewer symptoms than morning arrivals

Symptoms are less in those who have traveled the journey previously

Symptoms are less in those who had a shorter interval their last full nocturnal sleep in the departure city and their first full nocturnal sleep in the destination city

Bonus pearl:  Types of Jaundice by Age

CIWA-Ar (Clinical Institute Withdrawal Assessment of Alcohol Scale, Revised)

The use of a scoring system for the disposition of an ethanol withdrawal patient can be helpful. The CIWA-Ar Score can guide both treatment in the ED as well as admission versus discharge. Most studies have verified that a score of <8 can be treated outpatient; 8-15 requires treatment and >15 wil require admission/IV benzodiazepines.

N/V: 0-7 (None to Constant N/V)

Tremor: 0-7 (None to Severe even with arms not extended)

Sweats: 0-7 (None to Drenching Sweats)

Anxiety: 0-7 (None to panic attack/delirium)

Agitation: 0-7 (None to pacing/thrashing during interview)

Tactile Disturbance: 0-7 (Mild itching to Continuous Hallucinations)

Auditory Disturbances: 0-7 (None to Continuous Hallucinations)

Visual Disturbances: 0-7 (None to Continuous Hallucinations)

Headache: 1-7 (Miild to Extremely Severe)

Orientation: 0-4

Go to this website to see the actual tool and how it should be administered:

http://www.regionstrauma.org/blogs/ciwa.pdf

Steroids and Septic Shock

• Do low-dose steroids improve mortality or shock reversal in patients with septic shock?
• A recent systematic review published in the Journal of Emergency Medicine found:
  • A statistically significant improvement in shock reversal (RR 1.17)
  • A favorable, but not statistically significant, mortality benefit for patients with refractory septic shock (RR 0.92; CI 0.79-1.07)
• Most guidelines recommend against steroids for septic patients that are responding to fluid resuscitation and vasopressor therapy.
• Updated guidelines from the Surviving Sepsis Campaign (soon to be published) will continue to recommend low-dose IV corticosteroids (200 mg over 24hrs) for those who are refractory to fluids/vasopressors.

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Question

Find four abnormalities in the chest Xray below.

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Humerus Fractures, Proximal

• Proximal fractures of the humerus only account for about 5% of all fractures but account for 45% of all humeral fractures.
• We should be familar with the Neer Classication System for Humeral fractures, which can also be seen at http://health-7.com/Handbook%20of%20Fractures/15%20-%20Proximal%20Humerus%20Fractures
   
• The classification system classifies fractures based on
  • 1-part
  • 2-part
  • 3-part
  • 4-part
• The bony segments that make up the parts are
  • Greater Tuberosity (GT)
  • Lesser Tuberosity (LT)
  • Humeral Head
  • Humeral Surgical Neck (SN)
• A part is defined as displaced if >1 cm of fracture displacement or >45 degrees of angulation.
• The greater the number of parts the more likely the patient will require surgery or have increased complications.
  • 3 and 4 part fractures are often fixed surgical due to the increased risk of vascualr compromise to the humeral head.

Wernicke encephalopathy (WE) is a neurologic disorder secondary to prolonged thiamine deficiency; it is characterized by confusion, ataxia, and ocular abnormalities. 

Traditional medical teaching advises against the administration of glucose (or glucose containing fluid) in thiamine deficient patients, without first giving thiamine, as this may precipitate WE. 

This teaching is problematic, however, in hypoglycemic patients who require the immediate administration of glucose while simultaneously being suspected of thiamine deficiency (e.g., malnourished alcoholics). Delays in treating hypoglycemia may be more harmful (e.g., seizures, permanent neurologic deficits, etc.) than the risk of WE.

Schabelman et. al performed a literature search to unearth the origins of this teaching. Nineteen papers related to this topic were found consisting of case reports, animal studies, and expert opinion; there were no randomized trials, cohort studies, or case-control studies.

Bottom-line: The available evidence does not support withholding glucose treatment until thiamine can be administered and educators should consider abolishing this dogmatic teaching until better evidence is available.

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Question

23 year-old female presents complaining of progressive right lower quadrant pain after doing "vigorous" pushups. CT abdomen/pelvis below. What’s the diagnosis? (Hint: it’s not appendicitis)

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Atrial fibrillation is most commonly associated with cardiovascular disease    

Non cardiac causes: pulmonary disease/PE, hyperthyroidism, sympathomimetics, drugs/ETOH

AFFIRM & RACE trials compared outcomes of a fib patients treated w/ rate vs. rhythm control

    - No significant difference in survival between groups

Risk of thromboembolic CVA

   - Rhythm control = Rate control + anticoagulation

New data challenges the need for strict heart rate control

   - Resting heart rate should be <110 bpm

Use CHADS2 score to identify who requires anticoagulation based on %risk of emboli 

   - Chronic heart failure, HTN, Age>75, DM, Stroke/TIA 

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