UMEM Educational Pearls

Question

9 month-old presents with wheezing and the CXR is shown below. What's the diagnosis?

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• MI without obstructive CAD is common, occurring in 5–10% of patients w/woman most commonly affected
• Mechanisms for MI without obstructive CAD include vasospasm, embolism, myocarditis, dissection, tako-tsubo, and occult plaque rupture
• Recent studies have applied cardiac MRI (CMR) with intravascular ultrasound  (IVUS) to determine the mechanism of MI without obstructive CAD
• In this study plaque disruption frequently occurred when the angiogram was normal or showed minimal atherosclerosis; Plaque rupture was demonstrated on IVUS in ~40% of women studied
• IVUS and CMR identified the potential mechanism of MI in 70%
• Consider theses adjunctive tools in the assessment of all patients with a clinical syndrome of MI who do not have obstructive CAD at angiography

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Adhesive capsulitis aka frozen shoulder

idiopathic loss of BOTH active and passive motion (this is a significant reduction of at least 50%)

               Motion is stiff and painful especially  at the extremes

Occurs due to thickening and contracture of the shoulder capsule

Affects patients between the ages of 40 and 60

Diabetes is the most common risk factor

Imaging is normal and only helpful to rule out other entities such as osteophytes, loose bodies etc.

Treatment includes NSAIDs, moist heat and physical therapy.

Patients should expect a recovery period of 1-2 years!

Ultrasound findings of appendicitis

• noncompressible appendix with an outer diameter in any portion > 6mm
• appendicolith
• hyperechoic periappendiceal fat
• loss of echogenic submucosal layer
• increased blood flow of the appendix on color Doppler ultrasound scanning
• periappendiceal collections seen in the absence of a visualized abnormal appendix

Ultrasound images:
http://www.youtube.com/watch?v=d9jKM6x52nk
http://sonocloud.org/watch_video.php?v=MWHM3D7KD25H
http://sonocloud.org/watch_video.php?v=54862AYWGHGA

Utilizing 20% lipid emulsion at a dose of 1.5 mL/kg (100 mL Bolus) IV with repeat in 15 minutes in no response is being recommended in patients hemodynamic instabiity due to poisoning.

Probably more effective in lipophilic drugs is a current theory for the mechanism of action - the "lipid sink". The idea is that the lipids envelope the drug pulling it off its receptors or sequestering it in the intravascular space. A recent paper has added another mechanism - direct inotropic and lusiptropic effects.(1)

Also, if you think the therapy is experimental, think again. Another recent paper surveyed Poison Control Centers and found 30/45 Poison Centers in the US have a defined protocol for utilization of lipid emulsion therapy. The PCCs are recommending it more.(2)

What was once considered just a purely experimental therapy only used at the very end of code is becoming more mainstream. Comfort with its safety profile and anectodotal effiicacy continues to mount.

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Clinical Presentation:

- A 40-year-old Hispanic man was admitted to the hospital after being found unconscious. He had a 2-day history of disorientation that manifested itself as his being unable to recognize family members.

- Upon admission he regained consciousness, becoming alert and oriented, but developed urinary retention and was unable to move or feel his lower extremities.

- Spinal MRI (with and without gadolinium) showed the spinal cord to be abnormally diffuse, with swelling and edema in the cervicothoracic region.

Diagnosis:

- After an extensive work up for lymphoma and CNS infection, he was discovered to have toxoplasmosis and was found to be HIV positive, which was previously undiagnosed.  

Discussion:

- Approximately 10% of patients with AIDS present with some neurological deficit as their initial complaint, and up to 80% will have CNS involvement during the course of their disease.

- Myelitis is a known complication of AIDS and is occasionally the initial complaint.

      The incidence of myelopathy may be as high as 20%, with 50% of the cases reported post-mortem

- Toxoplasmosis is the most common cause of cerebral mass lesions in patients with AIDS

      Occurring in 3–10% of patients in the United States and in up to 50% of AIDS patients in Europe, Latin America, and Africa

Bottom Line:

New neurological deficit in any patient should raise suspicion of HIV infection

Most patients with AIDS that present with evolving myelopathy, characterized by extremity weakness, sensory involvement, spinal cord enlargement, enhancing lesions in brain or spinal cord CT or MRI, have toxoplasmic myelitis

University of Maryland Section of Global Emergency Health

Author: Terrence Mulligan DO, MPH

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The Macklin Effect

Pneumomediastinum (click here for image) may be caused by many things:

1. Esophageal perforation (e.g., complication from EGD)
2. Tracheal / Bronchial injury (e.g., trauma, complication of bronchoscopy, etc.)
3. Abdominal viscus perforation with translocation of air across the diaphragmatic hiatus
4. Air may reach mediastinum along the fascial planes of the neck.
5. Alveolar rupture, also known as the "Macklin Effect"

The "Macklin Effect" is typically a self-limiting condition leading to spontaneous pneumomediastinum and massive subcutaneous emphysema after the following:

1. Alveolar rupture from increased alveolar pressure (e.g., asthma, blunt trauma, positive pressure ventilation, etc.)
2. Air released from alveoli dissects along broncho-vascular sheaths and enters mediastinum
3. Air may subsequently track elsewhere (e.g., cervical subcutaneous tissues, face, epidural space, peritoneum, etc.)

Pneumomediastinum secondary to the Macklin effect frequently leads to an extensive workup to search for other causes of mediastinal air. Although, no consensus exists regarding the appropriate workup, the patient's history should guide the workup to avoid unnecessary imaging, needless dietary restriction, unjustified antibiotic administration, and prolonged hospitalization.

Treatment of spontaneous pneumomediastinum includes:

• Supplemental oxygen and observation for airway obstruction secondary to air expansion within the neck
• Avoiding positive airway pressure, if possible
• Avoiding routine chest tubes (unless significant pneumothorax is present)
• Administering prophylactic antibiotics are typically unnecessary
• Ordering imaging as needed

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Question

30 year-old male presents with right wrist pain after falling off his bicycle. What's the diagnosis?

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• The ADAPT (2-Hour Accelerated Diagnostic Protocol to Assess Patients With Chest Pain Symptoms Using Contemporary Troponins as the Only Biomarker) trial was a prospective observational validation study designed to assess a predefined ADP (Accelerated Diagnostic Protocol)
• A low risk patient in this ADP was defined by TIMI 0, ECG w/no ischemic changes, and negative troponin at 0-and 2-hours after presentation
• Primary endpoint was assessment of any major adverse cardiac event (MACE)
• Of 1,975 patients enrolled, 302 (15.3%) had a MACE
• ADP classified 392 patients (20%) as low risk and only 1 (0.25%) had a MACE
• ADP had a sen 99.7%, NPV 99.7%, spec 23.4%, and PPV 19.0%
• Despite ADP identifying patients as low risk for MACE standard of care still requires rapid early outpatient follow-up or further inpatient testing 

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Fabella Syndrome

The fabella is a sesamoid bone that is embedded in the tendon of the gastrocnemius muscle where the fibers of the popliteus, arcuate complex and the fibular-fabellar ligament attach.

Fabella syndrome is a painful condition of the posterolateral knee that is exacerbated when the knee is extended.  The pain can be exacerbated by palpation of the fabella and if it is compressed against the condyles. The condition is most common in adolescence, but occurs in adults too.

Consider this condition in patients with posterolateral knee pain, which can also be due to tears of the  posterior horn of the lateral meniscus, and tendonitis of the lateral head of the gastrocnemius.

General information:

·      Salmonella typhi – transmission through fecal-oral, contaminated food, human carriers

·      Most cases in the US acquired abroad – Africa, Latin American, Asia

·      Vaccine available – not life-long immunity, need 1-2 weeks to take effect

Clinical Presentation:

·      sustained high fever (103-104)

·      Faget sign: fever and bradycardia (also seen in yellow fever, atypical pneumonia, tularemia, brucellosis, Colorado tick fever))

·      Abdominal pain, GI bleed/perforation, hepatosplenomegaly, delirium

·      “Rose spots” – erythematous macular rash over chest and abdomen

·      Without treatment sx can resolve after 3-4 weeks, mortality from secondary infections 12-30%

Diagnosis:

·      Pan-culture for S. typhi

·      Serologic: Widal test (negative for 1^st week of symptoms, 7-14 days to result)

Treatment:

·      Abx: amoxicillin, trimethoprim-sulfamethoxazole, and ciprofloxacin

·      MDR typhoid: ceftriaxone or Azithromycine 1^st line

Bottom Line:

·      Get vaccinated if travelling to endemic areas 1-2 weeks before travel

·      Suspect in travelers to endemic areas with sustained high fevers

·      Spontaneous resolution does occur but may become carriers without abx

Famous victims or Typhoid fever:

·      Wilbur Wright (Wright brothers)

·      Prince Albert (Queen Victoria’s husband)

·      Hakaru Hashimoto (discovered Hashimoto’s thyroiditis)

·      Abigail Adams (1^st Lady, wife of John Adams)

University of Maryland Section of Global Emergency Health

Author: Veronica Pei, MD

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Monitoring Hyperosmolar Therapy

• Hyperosmolar therapy (mannitol or hypertonic saline) is commonly used in the treatment of neurocritical care paitents with elevated ICP.
• When administering mannitol, guidelines recommend monitoring serum sodium and serum osmolarity.  Though targets remain controversial, most strive for a serum sodium of 150-160 mEq/L and a serum osmolarity between 300 - 320 mOsm/L.
• Unfortunately, serum osmolarity is a poor method to monitor mannitol therapy.
• Instead of serum osmolarity, follow the osmolar gap.  It is more representative of serum mannitol levels and clearance.  If the osmolar gap falls to normal, the patient has cleared mannitol and may be redosed if clinically indicated. 

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Question

60 year-old male with a history of pulmonary fibrosis presents to the Emergency Department after a lung biopsy. He is complaining of facial swelling and dyspnea. What's the diagnosis?

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• Cardiorenal syndrome (CRS) type 1 is the development of acute kidney injury (AKI) in the patient with acute cardiac illness, most commonly acute decompensated heart failure (ADHF)
• Multiple pathophysiological mechanisms result in CRS characterized by a rise in serum creatinine, oliguria, diuretic resistance, and worsening ADHF
• There are a host of predisposing factors that create baseline risk for CRS (DM, HTN, HLD, OSA)
• The final common pathway often results in bidirectional organ injury, drug resistance, and death 
• The combination of worsening renal function, volume overload, and diuretic refractoriness makes the management of CRS challenging
• Current therapies although often ineffective include aggressive diuresis and positive inotropes

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Diffuse Idiopathic Skeletal Hyperostosis

aka 1) ankylosing hyperostosis, 2) Vertebral osteophytosis

Large amount of osteophyte formation in the spine, confluent, spanning 3 or more disks

Most commonly seen in the thoracic and thoracolumbar spine.

Osteophytes follow the course of the anterior longitudinal ligaments.

2:1 male to female ratio. Most patients >60yo.

Sx's: Longstanding morning and evening spine stiffness.

PE: Spinal stiffness with flexion and extension.

Dx: plain films

Tx: NSAIDs and physical therapy

http://www.learningradiology.com/caseofweek/caseoftheweekpix2013%20538-/cow542-1arr.jpg

• diarrhea lasting less than 14 days
• in children, almost all diarrhea is due to an infectious agent
• most etiologies are self-limited and do not need further evaluation except in the following conditions:

1. infants < 2 months of age
2. gross blood in stool
3. WBC's on microscopic exam of stool
4. toxic-appearance
5. immunocompromised child
6. diarrhea developing while an inpatient

• therapy is aimed at oral rehydration and providing nutrional needs
• ORT is best with commerical formulations specific for this as most other clear liquids (juice, sodas) are hypertonic and have excess glucose resulting in ongoing diarrhea-like stools
• after rehydration, resume the child's normal diet. 

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Strychnine poisoning is still occasionally found in rat poisons and in adulterated street drugs and herbal products. The typical symptoms are involuntary, generalized muscular contractions resulting in neck, back, and limb pain. The contractions are easily triggered by trivial stimuli (such as turning on a light) and each episode usually lasts for 30 seconds to 2 minutes, for 12 to 24 hours. Classic signs include opisthotonus, facial trismus, and risus sardonicus.

Differential diagnosis includes:

• Tetanus: However, the onset of symptoms is more gradual and the duration much longer than in the case of strychnine poisoning.
• Generalized seizures: However, strychnine poisoning presents with a normal sensorium during the period of diffuse convulsions.
• Dystonic reaction: However, dystonic reactions are usually static, whereas strychnine poisoning results in dynamic muscular activity. 
• Serotonin syndrome
• Malignant hyperthermia
• Neuroleptic malignant syndrome
• Stimulant use

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Case Presentation:

A Spanish speaking man in his late 20s is brought in by ambulance for severe dyspnea.  Given the language barrier and his clinical status you are unable to obtain any history. He is tachypnic, had a low pulse ox, and was placed on BiPAP.  On exam you hear bibasilar rales and a faint holosystolic murmur.

Clinical Question:

What should be included in the differential?

Answer:

Rheumatic heart disease is the result of valvular damage due to an abnormal immune response following a group A streptococcal infection.  It affects 15.6 to 19.6 million people worldwide.  Most patients present with dyspnea between the ages 20-50.  The most common valvular disease is mitral insufficiency, but it may present with mitral stenosis or aortic regurgitation.  The disease is most prevalent in sub-Saharan Africa and among the Indigenous population of Australia but it can be found in many developing countries.  People who live in rural areas without access to medical care are those at highest risk for developing rheumatic fever and subsequently rheumatic heart disease.

Bottom Line:

Rheumatic heart disease should be considered in patients who present from an endemic region.

University of Maryland Section of Global Emergency Health

Author: Jenny Reifel Saltzberg, MD, MPH

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Fluid boluses are often administered to patients in shock as a first-line intervention to increase cardiac output. Previous literature states, however, that only 50% of patients in shock will respond to a fluid bolus. 

Several validated techniques exist to distinguish which patients will respond to a fluid bolus and which will not; one method is the passive leg raise (PLR) maneuver  (more on PLR here). A drawback to PLR is that it requires direct measurement of cardiac output, either by invasive hemodynamic monitoring or using advanced bedside ultrasound techniques.

Another technique to quantify changes in cardiac output is through measurement of end-tidal CO2 (ETCO2). The benefits of measuring ETCO2 is that it can be continuously measured and can be performed non-invasively on mechanically ventilated patients.

A 5% or greater increase in end-tidal CO2 (ETCO2) following a PLR maneuver has been found to be a good predictor of fluid responsiveness with reliability similar to invasive measures.

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Question

38 year-old male with a past medical history of diabetes presents with back pain and hypotension. CT scan is shown below. What's the diagnosis?

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