UMEM Educational Pearls

• Mirror-image dextrocardia is the most common form of cardiac malposition and is commonly associated with situs inversus of the abdominal organs
• The anatomic right ventricle is anterior to the left ventricle and the aortic arch curves to the right and posteriorly
• 25% percent of these patients will have associated sinusitis and bronchiactasis (Kartagener’s syndrome)
• ECG changes associated with dextrocardia include:

1. Right-axis deviation
2. Global negativity in leads I and aVL (negative QRS w/inverted P and T waves)
3. Lead aVR similar to the normal aVL (positive QRS)
4. Absent R wave progression in precordial leads/dominant S waves

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Background

In the current era of community-acquired MRSA (CA-MRSA), most of our outpatient treatment options for cellulitis aim to cover MRSA. Choices include sulfamethoxazole/trimethoprim (SMZ-TMP), doxycycline, linezolid, and clindamycin (depending on local susceptibility patterns).

A New Study

• In a double-blind, placebo-controlled trial 146 patients with cellulitis were randomized to receive cephalexin alone or cephalexin + SMZ-TMP for 7-14 days
• Lots of exclusion criteria basically narrowed the patient population to uncomplicated cellultits with no history of diabetes or other immunocompromising conditions
• Cure rates up to 30 days post-treatment were the same between the two groups (>80%)

Take Home Clinical Points

• Even in communities with high prevalence of MRSA, uncomplicated cellulitis cases without pus generally seem to be strep species.
• Therefore, make sure to include an anti-streptococcal component (such as cephalexin) to the MRSA agent (doxycycline or SMZ-TMP). Clindamycin has sufficient strep coverage by itself (but may not adequately cover MRSA).
• Given the potential for MRSA infections to deteriorate quickly and the inability to differentiate staph from strep without cultures, MRSA coverage should still be considered.

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Hyperglycemia in the setting of antipsychotic use has been reported mostly with olanzapine (Zyprexa) but does occur with other antipsychotics. A recent study from the NYC medical examiner's office details 17 deaths of DKA due to antipsychotics and found that (from highest to lowest incidence) quetiapine > olanzapine > risperidone were the atypical antipsychotics found with these deaths.

Remember hyperglycemia occurs with patients on antipsychotics and can lead to hyperglycemia hyperosmolar coma or DKA. Both can be lethal.

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Background Information:

Each year, an estimated 50 million travelers from Western countries visit tropical regions all over the world.

Given the potentially serious consequences for the patients and, their close contacts and healthcare workers it is important that life threatening tropical diseases are swiftly diagnosed.

Pertinent Study Design and Conclusions:

- Descriptive analysis of acute and potentially life threatening tropical diseases among 82,825 ill western travelers reported to GeoSentinel from June of 1996 to August of 2011.

- Of these travelers, 3,655 (4.4%) patients had an acute and potentially life threatening disease.

- The four most common conditions being falciparum malaria (76.9%), typhoid fever (11.7%), paratyphoid fever (6.4%), and leptospirosis (2.4%).

Bottom Line:

Western physicians seeing febrile and recently returned travelers from the tropics need to consider a wide profile of potentially life threatening tropical illnesses, with a specific focus on the most likely diseases described in this case series.

University of Maryland Section of Global Emergency Health

Author:  Walid Hammad, MB ChB

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End-expiratory Occlusion Test

• Volume expansion is a cornerstone of resuscitation for circulatory failure.
• As discussed in previous pearls, only 50% of unstable critically ill patients respond to fluid therapy.  For the 50% that don't respond, additional fluids may increase morbidity and mortality.
• In recent years, there has been tremendous focus on dynamic markers of fluid responsiveness, including respirophasic changes in IVC diameter, passive leg raising, and pulse pressure variation (PPV).
• An additional dynamic marker of fluid responsiveness is the end-expiratory occlusion test.
• Unlike PPV, this test can be performed on patients with spontaneous breathing activity and those with cardiac arrhythmias.
• Recent literature indicates that a 5% increase in cardiac output during a 15-second end-expiratory occlusion test predicts a positive response to a 500 ml saline infusion.

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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