UMEM Educational Pearls

Category: Toxicology

Title: Arsenic and Agatha Christie

Keywords: Arsenic poisoning (PubMed Search)

Posted: 10/19/2017 by Hong Kim, MD, MPH
Click here to contact Hong Kim, MD, MPH

Agatha Christie is an English crime novelist who frequently used poisons in her books to murder the victims. In her book, Murder is Easy, Ms. Christie uses arsenic/arsenic trioxide to kill several characters.


Primary source of arsenic in general population is contaminated food, water and soil. Arsenic exists in several forms: elemental, gaseous (arsine), organic and inorganic (trivalent or pentavalent).


Arsenic trioxide has also been used to treat acute promyelocytic leukemia in China; it’s use in other leukemia, lymphoma, and other solid tumors are currently being investigated.


Arsenic primarily inhibits the pyruvate dehydrogenase complex and multiple other enzymes involved in the citric cycle/oxidative phosphorylation, resulting in mitochondrial dysfunction.


Acute toxicity of arsenic after ingestion

  1. GI symptoms (minutes to several hours) – nausea, vomiting, abdominal pain and cholera like diarrhea.
  2. Cardiovascular: QT prolongation/torsade de pointes, orthostatic hypotension, ventricular dysrhythmias, myocardial dysfunction and shock.
  3. CNS (days): encephalopathy, delirium, coma, and seizure due to cerebral edema and microhemorrhages.
  4. Respiratory: ARDS, respiratory failure,
  5. Others: AKI, leukemoid reaction, hemolytic anemia, and hepatitis.



  1. Chelation: dimercaptrol (BAL) or succimer
  2. Whole bowel irrigation if radiopaque material is present (abdominal XR)
  3. Electrolyte and fluid management
  4. Cardiac monitoring and pressor support in hypotension

Category: Critical Care

Title: Improving CPR Performance

Posted: 10/17/2017 by Mike Winters, MD (Updated: 2/23/2018)
Click here to contact Mike Winters, MD

Improving CPR Performance

  • High-quality CPR is the cornerstone of successfull resuscitation from cardiac arrest.
  • In fact, high-quality CPR is considered the most important intervention for achieving ROSC and good neurologic recovery.
  • Pearls for optimizing CPR performance include:
    • Use a team-focused approach
    • Avoid leaning and ensure complete recoil of the chest
    • Target a chest compression fraction of at least 60%
    • Use POCUS, but pay attention to the duration of hands-off time
    • Target ETCO2 of > 20 mm Hg

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Category: Orthopedics

Title: Osteochondritis Dissecans

Keywords: Knee pain (PubMed Search)

Posted: 10/14/2017 by Brian Corwell, MD (Updated: 2/23/2018)
Click here to contact Brian Corwell, MD

Complete or incomplete separation of the articular cartilage and subchondral bone

               -70% occur at the lateral aspect of the medial femoral condyle

               -Also seen in the talar dome and capitellum

Repetitive overloading leads to fragmentation and separation from surrounding bone

Prognosis better in kids than in adults

CC: Vague difficult to localize activity related pain and swelling. Mechanical symptoms only if loose body is present

PE: Wilson’s test

Internal tibial rotation and knee extension impinges the tibia on the OCD lesion causing pain. Pain abates with external rotation and flexion.

Plan of care: Limit activity and trial period of non-weight bearing for 6 weeks.

50% resolve in 10 to 18 months with conservative care.

Detached, loose or unstable fragments or failure of non-operative care will need surgery

Pediatric patients are at a higher risk of blunt renal injury due to multiple anatomic features, include relatively less protective perinephric fat and surrounding musculature, and larger size of the kidneys in relation to the abdomen compared to their adult counterparts (1). For this reason, it is important to keep a high clinical suspicion for renal injury in the pediatric patient with blunt abdominal trauma, particularly in those with lower rib fractures, direct injury, flank ecchymosis and/or tenderness, rapid deceleration injury, or other significant traumatic mechanism (2). Despite the risk of radiation exposure, the preferred imaging modality for the diagnosis of renal injury in pediatric patients is computed tomography (similar to adults). Studies evaluating the utility of renal ultrasound have demonstrated poor sensitivity with a decreased likelihood of diagnosing low-grade injuries. While ultrasound may be a useful screening tool to evaluate for severe injury, it should not be used to rule out traumatic injury (1). Take home point: Keep a high suspicion for renal injury in pediatric patients with blunt abdominal trauma and confirm the diagnosis with computed tomography of the abdomen and pelvis with contrast.

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Category: Toxicology

Title: Cannabinoid Hyperemesis Syndrome

Keywords: Cannabinoid, cyclic vomiting, Capsaicin (PubMed Search)

Posted: 10/12/2017 by Kathy Prybys, DO
Click here to contact Kathy Prybys, DO

Cannabinoid hyperemesis is a syndrome (CHS) characterized by severe intractable nausea, cyclical vomiting, and abdominal pain associated with chronic marijuana abuse. It is often a underrecognized cause of cyclic vomiting syndrome. Despite well established anti-emetic properties of marijuana, paradoxical effects on the GI tract exist through cannabinoid receptors which exert their neuromodulatory properties in the central nervous system and the enteric plexus. Multiple theories of mechanism of CHS are in the literature. Diagnosis is based on the following clinical criteria:

  • History of regular cannabis for any duration of time
  • Refractory nausea and vomiting
  • Gastrointestinal evaluations fail to identify other clear causes
  • Compulsive bathing in hot water temporarily alleviates symptoms often done several times a day. A red flag symptom.
  • Resolution of symptoms after cannabis is discontinued

Acute care goals are to treat dehydration and terminate nausea and vomiting. Administration of intravenous fluids, dopamine antagonists, topical capsaicin cream, and avoidance of narcotic medications are recommened treatment measures. Benzodiazepines followed by haloperidol and topical capsaicin are reported to be most effective. Capsaicin  activates the transient receptor potential vanilloid 1 receptors (TRPV1) which impairs substance P signalling in the area postrema and nucleus tract solitarius similar to noxious stimuli, such as heat. 

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Category: Neurology

Title: Traumatic Brain Injury in Older Adults - The Silver Tsunami?

Keywords: traumatic brain injury, TBI, fall, subdural hematoma, SDH, elderly (PubMed Search)

Posted: 10/11/2017 by WanTsu Wendy Chang, MD
Click here to contact WanTsu Wendy Chang, MD

Traumatic brain injury (TBI) is associated with close to half of major trauma admissions in adults over age 65 in the U.K.

Falls accounted for 85% of all TBIs, while 45% of patients had subdural hematomas (SDH).

More than 3/4 of patients were treated conservatively, though outcomes were not significantly better than those who underwent neurosurgical intervention.

Higher age is associated with higher mortality and greater disability.

Bottom Line: Trauma in older adults is increasing and fall prevention is important in reducing significant injuries.

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Category: Critical Care

Title: Liver Dialysis on MARS (Molecular Adsorbent Recirculating System)

Keywords: liver failure, dialysis, MARS, Molecular Adsorbent Recirculating System (PubMed Search)

Posted: 10/10/2017 by Kami Hu, MD
Click here to contact Kami Hu, MD


Molecular Adsorbent Recirculating System (MARS) is an artificial liver support system colloquially known in the medical field as "dialysis for the liver."  

  • Limited data, small studies
  • Consistently shown to improve hemodynamics, toxin clearance, and hepatic homeostasis
  • No consistent proven mortality benefit
  • Only performed by limited number of US hospitals (including the University of Maryland)
  • May depend on the acute liver failure subpopulation, but best use currently seems to be for severe acute liver failure due to a potentially reversible/recoverable cause (toxin ingestion, trauma, acute alcoholic hepatitis, etc) or as a bridge to transplant


1. Consider MARS in your patient with severe acute liver failure due to potentially reversible/recoverable etiology

2. Know if and where MARS is offered near you



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Category: Pharmacology & Therapeutics

Title: Fever Treatment in Sepsis

Keywords: antipyretic, sepsis, fever (PubMed Search)

Posted: 10/7/2017 by Ashley Martinelli (Emailed: 10/10/2017) (Updated: 2/23/2018)
Click here to contact Ashley Martinelli

Fever occurs in 40% of patients with sepsis.  Historically, there has been conflicting evidence of whether patient outcomes improve with antipyretic therapy.

A recent large meta-analysis assessed the effect of antipyretic therapy on mortality of critically ill septic patients.  The analysis included 8 randomized studies (1,531 patients) and 8 observational studies (17,432 patients) that assessed mortality of septic patients with and without antipyretic therapy.

The authors found no difference in mortality at 28 days or during hospital admission.  There was also no difference in shock reversal, heart rate, or minute ventilation.

As expected, they found a statistically significant reduction in posttreatment body temperature (-0.38°C, 95% IC -0.63 to -0.13) in patients who received antipyretic therapy.  NSAIDs and cooling therapies were more effective than acetaminophen, however no agent or dosing information was provided and only one study included physical cooling therapies.

Bottom Line: Antipyretic therapies do not reduce mortality in patients with sepsis, but they may improve patient comfort by reducing body temperature.


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Category: Pediatrics

Title: Risky Business in Bronchiolitis

Keywords: Pediatrics, Bronchiolitis, Respiratory Decompensation, Risk factors (PubMed Search)

Posted: 10/6/2017 by Megan Cobb, MD
Click here to contact Megan Cobb, MD


Bronchiolitis season will soon be upon us. Here are some risk factors for children under 2 y/o with bronchiolitis, who may be more likely to suffer respiratory decompensation:

1. Age under 9 months

2. Black race

3. Hypoxia documented in the ED

4. Persisent accessory muscle use. 

Bottom Line: Consider providing respiratory support sooner than later in bronchiolitic infants with risk factors for decompensation. For HFNC, start at 1.5 - 2.0 L/kg/min, and titrate to work of breathing and  0saturations. 


Pathophysiology: Bronchiolitis is a disease process that leads to inflammation of lower airways, causing bronchiolar edema, epithelial hyperplasia, mucus plugging, and air trapping or atelectasis. Common viral causes include RSV, Human Metapneumovirus, Rhinovirus, Influenza, and Parainfluenza. 

Clinical Course: For most strains, the disease course is often 5-7 days with the worst days being 3-5. The disease process can last longer, especially in neonates. The predominant presenting symptoms are often rhinorrhea, low grade fevers, and cough, but apnea can be the primary symptom in younger infants. As a result of increased work of breathing, PO feeding tolerance decreases and leads to dehydration. 

Treatment: Primarily supportive care with suctioning, hydration, supplemental oxygen via standard NC, HFNC, and in severe cases BiPAP, CPAP or intubation. Trial of bronchodilator is often used, but there is no role for repeated bronchodilator use if no benefit is seen in pre and posttreatment respiratory effort. Hypertonic saline is not recommended for routine use in the ED. Corticosteroids have no role for routine use in viral bronchiolitis, either.

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Category: Toxicology

Title: Hunan Hand

Keywords: Capsaicin, hunan hand, chili peppers (PubMed Search)

Posted: 10/6/2017 by Kathy Prybys, DO
Click here to contact Kathy Prybys, DO

Hunan hand syndrome is a painful contact dermatitis that frequently presents in cooks and chili pepper workers after preparing or handling chili peppers. Contact with other body parts gives rise to the terms: "Hunan nose" ''Hunan eye",and "Chili Willie". Capsaicin, found in the fruit of plants from the genus Capsicum such as red chili peppers, jalapeños, and habaneros, is a hydrophobic, colorless, odorless compound that binds with pain receptors causing the sensation of intense heat or burning. The "heat" or pungency of a peppers is measured in Scoville heat units (SHU), the number of times a chili extract must be diluted with water to lose heat. Habanero peppers generate 30,000 SHU. Even at low concentrations capsaicin is a skin irritant. It is the primary ingredient in pepper spray used in law enforcement and in personal defense sprays.   

Treatment consists of decontamination with water irrigation for opthalmic exposure and milk or antacids for dermal or gastrointestinal exposure. Burning can be recurrent and of of long duration depending on tissue penetration. Topical anesthetic especially for the eye and cool compresses for the skin can relieve pain.  Parodoxically capsaicin is used as a topical analgesic medication for local pain relief from muscle pain, itching,  and painful neuropathies (diabetic, postherpetic). Capsaicin initially causes neuronal excitation followed by a long-lasting refractory period due to depletion of substance P, during which neurons are no longer responsive to a large range of stimuli and thus are desensitized.



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Risk of Pneumocystis pneumonia  (PCP) increases with degree of immunosuppression. If clinical suspicion exists (CD4 <200 with cough, pulmonary infiltrates, hypoxic respiratory failure), it is reasonable to initiate empiric therapy. 

First line treatment is trimethoprim-sulfamethoxazole (TMP-SMX) orally or IV for 21 days.  IV pentamidine has equivalent efficacy to IV TMP-SMX but greater toxicity and is generally reserved for patients with severe PCP who cannot tolerate or are unresponsive to TMP-SMX.

Importantly, adjunctive corticosteroids have been shown to significantly improve outcomes (mortality, need for ICU admission, need for mechanical ventilation) in HIV-infected patients with moderate to severe PCP (defined by pO2 <70 mmHg on Room Air).

·      Ideally steroids should be started BEFORE (or at the same time as) Pneumocystis-specific treatment to prevent/mitigate the sharp deterioration in lung function that occurs in most patients after initiation of PCP treatment. This is thought to be secondary to the intense inflammatory response to lysis of Pneumocystis organisms, which can cause an ARDS-like picture.

·      Recommended dosing schedule: 40mg prednisone twice daily for 5 days,  then 40mg once daily for 5 days, followed by 20mg once daily for the remaining 11 days of treatment.


Bottom Line: In patients with moderate to severe PCP (pO2 <70 mmHg on RA), don’t forget to initiate adjunctive corticosteroids early (at the same time you initiate empiric therapy for PCP). 

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The current number of influenza cases in the Southern Hemisphere is substantially higher than normal.  For example, in Australia the number of influenza cases this year are twice the next highest year. 

Have you gotten your flu shot yet?

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Providing consistent, quality emergency care to the elderly is critically important. The Geriatric Emergency Department (GED) guidelines, developed collaboratively, provide a standardized set of guidelines to help improve care of the geriatric population in the emergency department.

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Category: Neurology

Title: tPA Contraindications

Keywords: stroke, tPA, thrombolytics, ICH, hemorrhage, adverse events (PubMed Search)

Posted: 9/28/2017 by Danya Khoujah, MBBS
Click here to contact Danya Khoujah, MBBS

Classically, the list of contraindications for tPA in stroke has been extensive and excludes a significant percentage of patients. This scientific statement from AHA clarifies the evidence behind these contraindications, and in short, expands the population of patients that should be considered for tPA.
The following is NOT considered a contraindication for tPA: 
- Age over 80 
- Severe stroke (NIHSS >25)
- Improving symptoms, if patient remains moderately impaired and potentially disabled
- A small (<10 mm) unruptured and unsecured intracranial aneurysm (NOT other vascular malformations)
- Extra-axial intracranial neoplasms (e.g. meningiomas, pituitary adenomas)
- Blood glucose of >400mg/dL that is subsequently normalized
- Seizure at onset of stroke if residual impairment is secondary to stroke not a postictal phenomenon 

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Category: Orthopedics

Title: Lever Sign for ACL tears

Keywords: ACL tear (PubMed Search)

Posted: 9/23/2017 by Brian Corwell, MD (Updated: 2/23/2018)
Click here to contact Brian Corwell, MD

Lever Sign/Lelli’s test

A new test for diagnosing ACL tears

Higher sensitivity (94 - 100%) than the Lachman test (highest sensitivity test to date)

               With time and more study, this may become our new gold standard physical examination test

Very easy to learn and apply to bedside care

Can help with diagnosing partial tears

Area of manipulation is the femur and not the tibia (as in other tests)

Consider incorporating into your standard knee examination

Original study


Thank you to Ari Kestler for sending

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Category: Pediatrics

Title: Pediatric Acute Respiratory Distress Syndrome (ARDS)

Keywords: ARDS, oxygenation index, OI, PALICC, acute lung injury (PubMed Search)

Posted: 9/22/2017 by Mimi Lu, MD (Updated: 10/27/2017)
Click here to contact Mimi Lu, MD

Since the first description of acute respiratory distress syndrome (ARDS), various consensus conferences (including American-European Consensus Conference (AECC) and the Berlin Conference) have produced definitions focused on adult lung injury but have limitations when applied to children. 

This prompted the organization of the Pediatric Acute Lung Injury Consensus Conference (PALICC), comprised of  27 experts, representing 21 academic institutions and eight countries.  The goals of the conference were 1) to define pediatric ARDS (PARDS); 2) to offer recommendations regarding therapeutic support; and 3) to identify priorities for future research in PARDS.

Although there were several recommendations from the group, some notable ones, in contrast to the Berlin definition focused on adults, include: 1) use the Oxygenation Index (or, if an arterial blood gas is not available, the Oxygenation Severity Index) rather than the P/F ratio; 2) elimination of the requirement for “bilateral” pulmonary infiltrates (may be unilateral or bilateral) 3) elimination of  specific age criteria for PARDS.

Tune in next month for pearls on management for children with PARDS...

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Category: Toxicology

Title: Drug Induced Hyperkalemia

Keywords: Hyperkalemia (PubMed Search)

Posted: 9/22/2017 by Kathy Prybys, DO (Updated: 10/5/2017)
Click here to contact Kathy Prybys, DO

Hyperkalemia is a potentially life threatening problem which can lead to cardiac dysrhythmias and death.  Drug interactions inducing hyperkalemia are extremely common such as the combination of ACE inhibitors and spironolactone or ACE inhibitors and trimehoprim sulfamethoxazole. Hyperkalemia can also occur with a  single agent and is a relatively common complication of therapy with trimethoprim sulfamethoxazole. The following drugs can cause hyperkalemia:

  • Ace inhibitors
  • Beta blockers
  • Cyclosporine
  • Digitalis
  • Non-steroidal Anti-inflammatory Drugs
  • Pentamidine
  • Potassium supplement
  • Succinylcholine
  • Tacrolimus
  • Trimethoprim sulfamethoxazole 


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The blue-ringed octopus (genus Hapalochlaena) is normally found in the Great Barrier Reef and other coastal waters and tide pools around Australia and other Western Pacific islands. Though not an aggressive animal, when it does bite, such as stepped upon, it can inject tetrodotoxin along with a number of other toxic compounds.


Tetrodotoxin can cause paralysis, leading to respiratory failure and death, though the blockage of voltage-gated fast sodium channel conduction, blocking peripheral nerve conduction. Treatment is supportive, as the venom usually wears off within 4 to 10 hours.

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Post-Arrest Tidal Volume Setting

  • Most patients with ROSC from out-of-hospital cardiac arrest undergo endotracheal intubation and mechanical ventilation.
  • Optimal management of mechanical ventilation for the post-arrest patient is currently not well defined.
  • A recent retrospective cohort study sought to determine if a lower tidal volume (Vt) was associated with improved neurocognitive outcome at hospital discharge.
  • Of 256 patients included in the study, investigators found:
    • 38% were ventilated with Vt > 8 ml/kg predicted body weight
    • Lower Vt was significantly associated with favorable neurocognitive outcome, decreased duration of mechanical ventilation, and decreased ICU length of stay
  • Take Home Pearl: Pay attention to Vt in the post-arrest patient.

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Elective surgeries with general anesthesia are often cancelled when the child has an upper respiratory tract infection.  What are the adverse events when procedural sedation is used when the child has an upper respiratory tract infection?

Recent and current URIs were associated with an increased frequency of airway adverse events (AAE).  The frequency of AAEs increased from recent URIs, to current URIs with thin secretions to current URIs with thick secretions.   Adverse events not related to the airway were less likely to have a statistically significant difference between the URI and non-URI groups

AAEs for children with no URI was 6.3%.  Children with URI with thick/green secretions had AAEs in 22.2% of cases.  Children with URIs did NOT have a significant increase in the risk of apnea or need for emergent airway intervention.  The rates of AAEs, however, still remains low regardless of URI status.



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