UMEM Educational Pearls

Acute brachial plexus neuritis is an uncommon disorder that is easily confused with cervical radiculopathy.

Patients present with a characteristic pattern of acute onset of burning pain.  Pain subsides in days to weeks and is then followed by profound weakness and muscle wasting changes affecting the shoulder  and upper extremity. Weakness is best identified in the deltoid, biceps and rotator cuff muscles. Strength gradually recovers over 3-4 months.

DDX:  The constellation of pain, weakness and sensory loss associated with cervical radiculopathy tend to occur simultaneously.  Also cervical radiculopathy tends to involve only a  single root.

ED treatment is with analgesics and physical therapy and PCP referral for outpatient MRI/EMG. Consider a sling in those with severe shoulder weakness.

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Caffeine can interfere with the successful reversion of paroxysmal supraventricular tachycardia (SVT) by adenosine.

Caffeine is an adenosine receptor blocker.

Ingestion of caffeine less than 4 hours before a 6-mg adenosine bolus significantly reduced its effectiveness in the treatment of SVT.  Theophylline is similar but not many patients are prescribed it anymore.

An increased initial adenosine dose may be indicated for these patients. A first dose of 12 mg (instead of 6), followed by 2nd and 3rd doses of 18 mg (instead of 12) may be indicated.

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• Infectious disease guidelines recommend that antibiotics be administered to patients in whom bacterial meningitis is suspected within 30 minutes of their presentation.
• Antibiotics do not appear to cause changes in cerebrospinal fluid (CSF) white blood cell, protein, or glucose levels which are compatible with impeding diagnostic utility.
• Additionally, CSF gram stain findings are not significantly changed by early antibiotic use, as these studies have been found to be diagnostic in most patients even if lumbar puncture (LP) is delayed by up to 3 days. 
• CSF cultures may be positive even after a single dose of antibiotics, although the yield decreases with more fastidious organisms such as meningococcus.
• In 86% of patients with bacterial meningitis, the causative organism may be isolated pre-antibiotic administration via blood culture.
• TAKE HOME POINT:  In cases of high suspicion for bacterial meningitis, do not delay administering antibiotics for the sake of first performing an LP, and have a low threshold to check blood cultures.

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When may an ED thoracotomy be futile?

• Performing an ED thoracotomy is incredibly stressful and a resource-intense procedure.
• While we've all learned that stab wounds to a ventricle have the highest survival rate, what about indicators that an ED thoracotomy may be futile?
• A recent study of 18 trauma centers across the US found that ED thoracotomy was unlikely to yield productive survival in the following:
  • Blunt trauma patients that require > 10 min of prehospital CPR without response
  • Penetrating trauma patients that require > 15 min of prehospital CPR without response
  • Patients presenting in asystole without evidence of pericardial tamponade on bedside ultrasound.

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Question

13 year-old right-hand dominant male following assault with blunt object. Diagnosis?

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Here are a few important points to keep in mind when evaluating elderly patients in the ED or when prescribing a new drug:

• Adverse drug effects lead to 11% of ED visits in patients > 65
• Older patients in the ED generally take > 4 medications per day, with 13% taking > 8 medications
• 11% of elderly patients in the ED receive at least 1 inappropriate medication
• 3 medication classes account for 48% of all ED visits for adverse drug effects in the elderly: oral anticoagulants or antiplatelet meds, antidiabetic medications, and agents with a narrow therapeutic index (e.g. digoxin, phenytoin)

Pay special attention to medication lists and new prescriptions in the elderly....much more attention than with younger patients!

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• We often see seizure patients on phenytoin therapy who have subtherapeutic levels.  Most patients do not require intravenous loading and can be adequately managed with oral treatment.
• To estimate what dose to prescribe, use the following equation: [0.7 x IBW x (15 - current level)].  For example if a 70 kg patient has a level of 8 mcg/mL (mg/L), we would need ~400 mg loading dose to achieve a level of 15.
• Phenytoin is known for its erratic absorption and propensity for causing GI upset with doses too high.  The recommended strategy is to avoid administering more than 400 mg at one time and separate the doses by 2 hours.  This would take three doses over 4 hours for a 1 gm load.
  • In the ED, an effective strategy for a 1 gm oral load is 500 mg now and 500 mg in 2 hours at discharge.  Patients tolerate it well, it cuts down on ED length of stay, and still achieves therapeutic levels.  Remember that an oral suspension formulation is also available.

1)      C-A-B for CPR. Now recommended to start compressions immediately instead of the conventional rescue breaths.

2)      Capnography during CPR. Continuous capnography recommended during CPR to guide the resuscitation, especially the effectiveness of chest compressions.

a.     If ETCo2 is less than 10 to 15 mm Hg consistently, focus your efforts on improving chest compressions.

3)      Etomidate for RSI induction.  Okay to use in infants and children, BUT not recommended for pediatric patients in septic shock.  Etomidate was not addressed in 2005 guidelines.

4)      Cuffed ET tubes. Acceptable to use in infants and children.

5)      Limit FiO2 after resuscitation.  Keep O2 sats ≥94%.  Avoid hyperoxia.

6)      Therapeutic hypothermia after cardiac arrest.  Recommendation based off of adult data, no pediatric prospective RCT done on this.  This is beneficial in adolescents with out-of-hospital VF arrest.

a.      Consider therapeutic hypothermia for infants and children.

b.      Cool to 32^oC-34^oC                                      

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o   The FDA is now asking manufacturers to limit the amount of acetaminophen in combination products to 325 mg per dose.

o   The higher dose formulations will be phased out by 2014.

o   The FDA is also considering lowering the maximum total to 3 gm per day, and a maximum dose of 650 mg per dose

o   This does not pertain to OTC, but this is likely to change in the near future; Johnson & Johnson (manufacturer of Tylenol) has already adopted these recommendations.

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• There is a host of contraindications to using thrombolytic therapy to treat acute ischemic stroke (AIS), one of which is recent surgery.

• It is likely that the quantity of patients presenting with AIS following oral surgery will rise given the increasing use of implants and more frequent discontinuation of anti-coagulants prior to dental procedures.

• While there is not much data on the risk of bleeding after use of thrombolytics in patients who have recently undergone minor dental surgery, some case reports have shown there to be an association with substantial hemorrhage.

• TAKE HOME POINT:  Remember to consider minor surgical procedures, such as dental, as a contraindication when screening acute stroke patients who are potential candidates for thrombolytic therapy; often, patients and their family members may not consider such procedures to be "surgery."

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Pregnancy causes many physiologic changes, which may be challenging during trauma resuscitations. A few pearls on the ABC’s:

Airway

• Increased progesterone levels cause mucosal hyperemia and edema, increasing risk of bleeding and smaller (i.e., edematous) airway.
• PEARL: Have smaller tubes ready and let the most experienced person intubate.

Breathing

• The enlarging uterus pushes the diaphragms into the thorax, reducing the total lung capacity and the functional residual capacity.
• PEARL: During intubation, patients in late pregnancy may have less oxygenation reserve and apnea time, desaturating faster during RSI.

Circulation

• The late stage uterus can compress the IVC when supine, reducing venous return to the heart (i.e., the Supine-Hypotension syndrome) subsequently reducing cardiac output.
• PEARL: Have a 30-degree wedge placed under patient's right hip, moving the uterus off IVC and improving venous return.
• BONUS PEARL: During resuscitation, ask medical students to manually move the uterus midline, relieving the compressed IVC. They will appreciate that you got them clinically involved.

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In a 1991 article published by Wrenn and Slovis, the ten commandments of emergency medicine are discussed. This is an awesome article and a must read for everyone in EM.

Michelle Lin recently mentioned these on her blog, Academic Life in Emergency Medicine....

The Ten Commandments of Emergency Medicine:

1. Secure the ABC's
2. Consider or give naloxone, glucose, and thiamine
3. Get a pregnancy test
4. Assume the worst
5. Do not send unstable patients to radiology
6. Look for common red flags
7. Trust no one, believe nothing (not even yourself)
8. Learn from your mistakes
9. Do unto others as you would do to your family (and that includes coworkers)
10. When in doubt, always err on the side of the patient

These are great teaching pearls for new interns and for the rest of us as well....

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Wound Repair

A pearl last year addressed the irrigation of wound and the fact that the type of fluid (sterile versus tap water) does not affect infection rates but rather the volume of irrigation is most important.

Sterile versus unsterile gloves have also been studied, and it turns out that clean unsterile gloves have the same rate of infection as sterile gloves but come with a substantial cost savings.

When caring for a contaminated wound it is most important to remove any gross contamination, and then irrigate the wound as much as possible.  A 20 mL syringe with an 18G angio-catheter provides the proper pressure to remove debris without causing tissue damage. The wound can then be closed wearing the gloves that are most comfortable or accessible to you.

Finally, from a medicolegal standpoint it is always best to inform the patient that you have tried to remove all of the contamination but there is still a chance that the wound can get infected. 

Acute Poststreptococcal Glomerulonephritis (APSGN) is a sequela of group A beta-hemolytic streptococci (GAS) infection of the skin or pharynx with nephrogenic strains of GAS.  Damage to the kidneys is due to deposition of antigen-antibody complexes in the glomeruli. 

Presentation:

Testing:

Treatment:

Prognosis (favorable):

Reference:

Kit, Brian. Assess the volume status and electrolytes in children with poststreptococcal glomerulonephritis. Avoiding Common Pediatric Errors. 2008. p356-57.

The incidence of tendon rupture related to fluoroquinolone use is reported to be in the range of 1 in 6000.

The risk of tendon rupture associated with FQ use is increased in those older than 60 years of age, those taking steroids, and in patients who have received heart, renal, or pulmonary transplants.

There is no evidence that tendon rupture is more likely for patients taking levofloxacin compared to other FQs.

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• Central Pontine Myelinolysis (CPM) is a largely irreversible, dreaded neurologic complication caused by osmotic demyelination, as a result of increasing sodium levels too rapidly.  It is definitively diagnosed via Brain MRI.

• Symptoms may include dysphagia, dysarthria, paraparesis, quadriparesis, lethargy, seizure, or even coma, and usually begin within 2 to 6 days following sodium elevation (i.e. may not be apparent in the emergency department).

• If the hyponatremic patient is symptom-free, treat conservatively by restricting oral fluid intake to less than 1500 mL per day.  Isotonic fluids (i.e. 0.9% normal saline) may be used, particularly if the patient is dehydrated.

• If the hyponatremic patient is symptomatic, hypertonic saline (i.e. 3%, start with 100 mL bolus) may be used.

• Increase sodium level by no more than 1.5 to 2 meq/L per hour for the first 3 to 4 hours until symptoms resolve.  Increase by no more than 10 meq/L in the first 24 hours.

• Take Home Point:  Prevent devastation of CPM by treating asymptomatic hyponatremia conservatively and by closely monitoring rate of sodium increase.

Blood Pressure in the Critically Ill Obese Patient

• Recall that incorrectly sized cuffs can significantly overestimate blood pressure, especially in obese patients.
• In fact, some studies show that false BP readings can occur in up to 75% of obese patients.
• By relying solely on noninvasive BP measurements, many of your critically ill obese patients may actually be hypotensive and under perfused.
• When you've got a sick obese patient, strongly consider early placement of an arterial line to assess and monitor blood pressure.

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Question

34 y.o. male with history of IVDA (intravenous drug abuse) complains of fever, chills and cough. Diagnosis?

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Clues to RV infarction:

1. This almost always occurs in the presence of a concurrent inferior MI.
2. Clinical findings may include the triad of hypotension, JVD, and clear lungs.
3. ECG clues: in the presence of inferior lead ischemia or injury pattern, look for:
     a. Combination of ST depression in lead V2 + ST elevation in lead V1; OR
     b. Combination of ST depression in lead V2 + isoelectric ST segments in leads V1 and V3; OR
     c. ST elevation in lead III markedly greater than the ST elevation in lead II; OR
     d. ST elevation in right-sided leads (requires you to obtain right-sided leads)

Why is this diagnosis important?
1. It suggests a larger infarction and worse prognosis, so BE AGGRESSIVE in management.
2. Be very cautious with preload-reducing medications (e.g. nitrates) in the acute management of these patients, as they may induce significant reductions in blood pressure and extension of the infarction. Be aggressive with IVF, while maintaining close attention to the lung sounds.

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Refractory Osteomyelitis is defined as a chronic osteomyelitis that persists or recurs after appropriate interventions have been performed or where acute osteomyelitis has not responded to surgery and antibiotics.

Case series, animal data and non-randomized prospective trials suggest that the addition of Hyperbaric Oxygen therapy to routine surgical and antibiotic management of previously refractory osteomyelitis is safe and improves the rate of infection resolution.

In patients with osteomyelitis involving spine, skull, sternum,  HBOT  is recommended prior to surgical intervention.  

Typically patients require 20-40 daily dives for sustained therapeutic benefit. 

How does HBOT work in osteomyelitis?

1.       Restoration of normal to elevated O2 level in infected bone.

2.       Leukocyte mediated killing of aerobic bacteria is restored when low O2 tension intrinsic to osteomyolitic bone is restored to physiologic or supra-physiologic levels.

3.       HBOT is noted to exert direct suppressive effects on anaerobic infections.

4.       HBOT augment the transport of certain abx (aminoglycosides and cephalosporins) across bacterial cell wall.

5.       Enhance osteogenesis

6.       Enhance angiogenesis

thank you to Dr. Sethuraman for this pearl

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