UMEM Educational Pearls

Increasing literature is supportive of the idea of electrically cardioverting new-onset atrial fibrillation (onset < 48 hours). The traditional concerns are that (1) cardioversion doesn't work well with atrial fibrillation and that (2) you will induce an embolic event. The literature actually indicates that both of these concerns are not true. The success rate of electrically cardioverting new-onset atrial fibrillation is actually >90% and the risk of embolism is < 1% (Burton, Ann Emerg Med). Many EDs already utilize such protocols that recommend routine cardioversion for these patients and discharge after a brief observation period.

In coming years, fueled by issues pertaining to hospital overcrowding and cost containment, we'll all be seeing more and more papers and guidelines recommending early electrical cardioversion, so if you aren't comfortable with the idea....you will be!

 

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Helpful clues in the evaluation of elbow trauma

Fat pads:  The fat pad sign can be seen with any joint effusion (infection, inflammation) but in the setting of trauma, effusions are indicative of fractures about the elbow (even if no fracture line can be identified).

There are two fat pads within the elbow. Normally, on a true  lateral radiograph only the anterior fat pad is seen as a small triangular radiolucent shadow anterior to the distal humeral diaphysis. The posterior fat pad is ordinarily not visualized on a lateral radiograph because it is tucked away within  the olecranon fossa. 

Normal lateral view: http://nypemergency.org/images/ElbowNormal.jpg

With fractures, the joint becomes distended with blood.  The anterior fat pad becomes displaced superiorly and outward from the humerus giving the so called "sail sign."  Similarly, the posterior fat pad gets displaced out of the olecranon fossa and becomes visible on the lateral radiograph. 

Anterior (sail) and posterior fat signs: http://nypemergency.org/images/Elbowsfatpadarrow.jpg

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A common debate on the topic of pediatric burns is whether or not blisters should be debrided.  ALL PEDIATRIC BURN BLISTERS SHOULD BE DEBRIDED.  There are two reasons for this:

1. Without debridement of burn blisters, the depth of a burn cannot be assessed, and such an assessment will certainly affect treatment and disposition.
2. There is conflicting (poor) evidence that blister fluid provides both protective and damaging properties, however, there is excellent evidence that ruptured blisters, or large blisters which are likely to rupture, carry a higher risk of infection if not debrided. Therefore, all blisters should be debrided. 

The best method for debriding blisters uses sterile gauze soaked in saline, and it is important to note that pain is almost universally decreased after debridement. 

The "1, 2, 3 Ouch!" technique is exactly what it sounds like (count to three with the child, and then wipe quickly, like tearing off a bandage), and works well in older children with smaller burn areas.  Sedation may be necessary for extensive debridements, and these children may need to be taken to the OR for debridement under anesthesia.  Some burn centers utilize non-operating room anesthesia (NORA) areas for such debridements that may be prolonged or painful, but do not require the full resources of an operating room.

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If benzodiazepines and supportive care fail to improve agitation and correct vital signs, several case reports indicate the successful use of cyproheptadine, an antihistamine with nonspecific antagonist effects at 5-HT_1A and 5-HT_2A receptors.

Cyproheptadine is available in 4 mg tablets or 2 mg/5 mL syrup. When administered as an antidote for serotonin syndrome, an initial dose of 8-12 mg is recommended, followed by 2 mg every two hours until clinical response is seen. Cyproheptadine is only available in an oral form, but it may be crushed and given through a nasogastric tube.

Cyproheptadine may lead to sedation, but this effect is consistent with the goals of management. It may also produce transient hypotension due to the reversal of serotonin-mediated increases in vascular tone. Such hypotension usually responds to IV fluids. Cyproheptadine is rated category B for safety in pregnancy by the FDA.

Consider the diagnosis of a Cervicogenic Headache when the following findings are present:

A. Pain localized to the neck and occipital region, potentially with projection to forehead, orbits, temples, vertex or ears.

B. Pain is precipitated or aggravated by particular neck movements or sustained postures.

C . At least one of the following:

1. Resistance to or limitation of passive neck movements.

2. Changes in neck muscle contour, texture, tone or response to active and passive stretching and contraction.

3. Abnormal tenderness of neck muscles.

D. Radiological imaging reveals at least one of the following:

1. Movement abnormalities in flexion/extension.

2. Abnormal posture.

3. Fractures, congenital abnormalities, bone tumors, rheumatoid arthritis or other distinct pathology (not spondylosis or osteochondrosis).

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Drug-Induced Hypophosphatemia

• Hypophosphatemia is seen in almost 30% of critically ill patients.
• As discussed in a prior pearl, hypophosphatemia can result in respiratory failure along with cardiac and neurologic abnormalities.
• Although common ED causes of hypophosphatemia include sepsis, hypothermia, and dialysis, don't forget about medications.
• Medications that can cause significant hypophosphatemia in the critically ill (along with their mechanism) include:
  • Decreased GI intake: antacids, sucralfate
  • Transcellular shift: aspirin overdose, albuterol, catecholamines, insulin, and bicarbonate
  • Increased urinary excretion: diuretics, acetaminophen overdose, and theophylline overdose

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Some Tips for Designing an Insanely Great Talk

Here are just a few things you can do to create a fantastic presentation:

• Remember: great talks mix education, entertainment, and inspiration
• Limit the number of bullet points. Text can be your enemy. Better yet, try to develop your talk without bullet points!
• Use more pictures and video. The more the better. 
• Tell stories and use emotion (people love stories and learn well from stories)
• In order to improve your speaking skills listen to recordings of yourself and watch videos of your presentations
• Spend extra time of developing an excellent opening and closing. Bombing these will seal your fate. 

Great website for making great, memorable slides:

http://www.brainslides.com/

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The ECG distinction between ventricular aneurysm vs. true STEMI is a tough one. Aside from reviewing the patient's history, here are a few pearls that may help.

1. Both entities cause Q-waves and STE that can be concave or convex upwards. However, aneurysms shouldn't cause reciprocal depression, whereas a true STEMI often does.
2. Serial ECGs and old ECGs are helpful. The aneurysm shouldn't change from a recent ECG or with serial testing, but STEMI ECGs often do, even over the course of 1-2 hours. Look for any changes in ST segments, T-wave morphology changes, or development of Q-waves.
3. Aneurysms are almost always associated with STE in the anterior leads (because most aneurysms involve the anterior wall). STEMI can involve anterior, lateral, or inferior wall.
4. Aneurysms are almost always associated with Q-waves, whereas STEMI may not (yet) have Q-waves.

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Some common injuries and their board review associated complications

• Anterior Shoulder Dislocation = Axillary nerve or artery injury
• Supracondylar Fracture = Brachial Artery injury
• Posterior Elbow Dislocation = Brachial Artery injury
• Knee Dislocation = Popiteal Artery Injury and Peroneal and tibial nerve injury
• Humeral shaft fracture = radial nerve injury
• Posterior hip dislocation = sciatica nerve injury
• Anterior hip dislocation = femoral nerve injury

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Pediatric Ethanol Ingestion

A young child is brought to you after accidentally drinking a shot of alcohol at a wedding party. Here is what you need to consider:

• Infants and young children who have ingested enough ethanol to cause a peak serum level ≥50 mg/dL (11 mmol/L) are at risk for profound hypoglycemia, in addition to the other effects of alcohol seen in adults The key is that the dangerous serum level is MUCH lower in children than in adults, and children require FAR smaller volume than what may be considered dangerous by adults.
• Supportive care is the key to good outcomes, with particular focus on treating hypoglycemia - check your D-sticks early and often.
• Consider child protective services involvement in every case of pediatric intoxication, and consider measurement of serum acetaminophen levels as well as other possible toxic ingestion candidates.
• Activated charcoal cannot adsorb ethanol and should only be used if other substances are being considered.
• Children who are asymptomatic for six hours, and have a safe home environment, may be discharged.

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The number of rabies vaccines recommended by the ACIP (Advisory Committee on Immunization Practices) has been reduced from 5 to 4 doses for unvaccinated patients.

This was based on evidence from multiple source, including pathogenesis data, animal trials, clinical studies, and epidemiological surveillance. The first dose of the 4-dose regimen should be administered as soon as possible after exposure (day 0). Additional doses are then given on day 3, 7, and 14. The first dose of rabies vaccine should be administered with HRIG, infiltrating as much as possible into the wound, with the remainder given IM at a distant site from the vaccine.

This recommendation is not applicable to immunocompromised patients, who should continue to receive the full five doses.

http://www.cdc.gov/vaccines/pubs/vis/downloads/vis-rabies.pdf

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Cluster headaches are defined as a group of at least five headache attacks causing unilateral orbital, supraorbital and/or temporal pain, with at least one of the following simultaneous associated findings on the affected side:

1. conjunctival injection
2. lacrimation
3. nasal congestion
4. rhinorrhea
5. ptosis
6. miosis
7. sweating on the forehead

Cluster headaches can occur at a frequency of one every other day t  eight episodes per day.

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Hypocapnia and Brain Injury

• Hypocapnia indirectly reduces cerebral blood volume through reductions in arterial cerebral blood flow.
• Despite its continued and frequent use, hypocapnia can actually aggravate cerebral hypoxia through reductions in oxygen supply and increases in cerebral oxygen demand.
• In addition to inducing further cerebral injury, hypocapnia can cause deleterious effects on the heart, lung, and GI tract.
• To date, there is no evidence that hypocapnia improves outcome in patients with traumatic brain injury or acute stroke.
• Induced hypocapnia in critically ill ED patients with acute brain injury should primarily be reserved for those with imminent brain herniation.

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Pulmonary Embolism and Blood Pressure

Patients with massive PE will often develop worsening hypotension after a fluid bolus due to increased right ventricular distension and deviation of the interventricular septum towards the left side of the heart. This septal deviation decreases left heart cardiac output.

In addition, patients with massive PE will sometimes develop higher blood pressures after intubation as positive pressure ventilation reduces preload, decreases deviation of the septum, and increases left sided cardiac output.

Diabetic Ketoacidosis Treatment:

• At least at our academic medical center, we find it very hard to get a DKA patient admitted to an ICU or IMC while they are still in DKA.  Typically, we can correct the acidosis and downgrade them to a floor bed before their ICU/IMC bed is available.
• Some key points to remember when managing DKA in the ED.
  • The mainstay of treatment for the hyperglycemia initially is IV fluids.
  • Check labs often and replete Magnesium and Potassium early.
  • Insulin should not be started until the potassium is confirmed to be >3.3 mEq/L
  • Patients can still be in DKA even though there glucose is normal.
  • Intravenous insulin must be continued until all the ketones are cleared. 
  • Add D5W or D10 if needed to ensure that their glucose levels stay up but do not stop the insulin.
  • Patients need to receive a long acting insulin (i.e.: Lantus or NPH) 2 hours before the insulin drip is stopped.  Placing a patient only on Sliding Scale Insulin will almost guarantee that they go back into DKA on the floor.
  • Typically you can just restart the patients home long acting insulin, but if you are leary about hypoglycemia if they are not eating well, then give them 3/4 their home dose.

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• newborns have increased rates of bilirubin production due to RBC's with shorter life spans, and a decreased rate of bilirubin elimination due to decreased ability of the neonatal liver to conjugate bilirubin
• about 60% of newborns will become clinically jaundiced
• bilirubin levels peat at 4 days of life,  and may not decline before day 7
• admission and treatment should be considered urgently when serum total bilirubin >25mg/dL, with exchange transfusion if it is >30mg/dL or the infant has signs of kernicterus
• there are nomograms which plot the bilirubin level according to the infant's age in hours to determine if an infant is at risk for being at toxic levels
• the most common pathologic etiologies are due to increased bilirubin production: blood-group incompatibilities, RBC-enzyme deficiency, and RBC structural defects
• when jaundice occurs between days 4-7, strongly consider sepsis, UTI, congenital infection (syphilis, CMV, etc)

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Ingestion of caustics can lead to immediate burns to mouth, esophagus, stomach as well as possible perforation. Months and years later, further complications are esophageal stenosis and increased incidence of esophageal carcinoma. The main benefit to EGD is to determine extent of injury within the esophagus. The lesions are graded much like a burn: 

Grade I: Mild burn, no risk for esophageal stenosis

Grade II: Moderate, if circumferential, patient is at risk for esophageal stenosis

Grade II: Eschar present, high risk of perforation as well as esophagel stenosis

You can make a case that all intentional-suicidal ingestions of caustics should undergo EGD since there should be some injury if ingestion truly occurred or at the least a higher probability. The difficult case is the pediatric unintentional ingestion. Utilizing clinical exam and history will assist with that determination - there is a little research to guide this decision (next pearl)

The attached picture is the post-mortem of a caustic injury showing grade II linear lesions in esophagus with eschar distally and in stomach (Grade III).

Migraine with aura (MA) diagnostic criteria

A. At least two attacks with at least 3 of the following:

1. One or more fully reversible aura symptoms (indicates focal cerebral cortical and/or brain stem functions).

2. At least 1 aura symptom develops gradually over greater than 4 minutes, or 2 or more symptoms occur in succession.

3. No aura symptom lasts greater than 60 minutes.

4. Headache follows aura with free interval of at least 60 minutes.

B. At least 1 of the following aura features establishes a diagnosis of migraine with typical aura:

1. Homonymous visual disturbance.

2. Unilateral paresthesias and/or numbness.

3. Unilateral weakness.

4. Aphasia or speech difficulty.

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Drug-Induced Thrombocytopenia

• Thrombocytopenia is common in critically ill patients and is associated with increased mortality.
• Up to 25% of critically ill patients will develop thrombocytopenia as a result of a medication, termed drug-induced thrombocytopenia (DIT)
• Antibiotcs are a common, yet infrequently recognized, cause of DIT.
• Antibiotics reported to cause DIT include linezolid, vancomycin, trimethoprim/sulfamethoxazole, and the beta-lactams.
• In fact, piperacillin/tazobactam has been associated with DIT more frequently than any other penicillin. 

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Classic electrocardiographic findings for hypokalemia:
u-waves (produces appearance of long QT), especially in the precordial leads
ventricular ectopy (PVCs typically)
ST segment depression or downward sagging, especially in the precordial leads

note that the sagging ST segments that terminate in large U-waves end up producing biphasic T-waves; these have the mirror image appearance of Wellens waves