Here are the learning pearls from our weekly Grand Rounds. Thanks to Dr. Hutchison, Dr. Murali, Dr. Cole, and Dr. Omori for presenting the following information!
Guillain-Barre Syndrome - Heidi Hutchison, MD
Pathophysiology one-liner:
Acute inflammatory demyelinating polyneuropathy causing progressive symmetric distal weakness and paralysis, occurring days to weeks after acute or chronic infection
Diminished or absent deep tendon reflexes
CLINICAL DIAGNOSIS: Do a good neuro exam. But beware, GBS has variable presentations so have a high index of suspicion
Only 25% of GBS cases are accurately diagnosed on the first ED visit; average of 2 visits needed to make the right diagnosis
Helpful studies: CSF analysis and Electromyography
1/3 of patient require intubation, have a low threshold. Consider the 20-30-40 rule* but also use other factors such as:
work of breathing, respiratory rate, oxygenation variables, CO2 retention, and trends in these values
Dispo: typically ICU
Treatments: Plasma exchange or IVIG. No steroids (oral steroids delay recovery and IV steroids have no benefit)
*20-30-40 rule: Intubate if:
Forced Vital Capacity < 20mL/kg
Maximal Inspiratory Pressure < 30cmH2O
or Maximal Expiratory Pressure < 40cmH2O
However, there is not a lot of research supporting intubation based on pulmonary function tests only (see this EMCrit post by PulmCrit for more information).
Myasthenia Gravis - Shyam Murali, MD
Pathphysiology one-liner:
Autoimmune attack on postsynaptic Acetylcholine Receptors at the NMJ (variants exist)
Fluctuating “true” muscle fatigue, not generalized weakness or feeling of tiredness; worse later in the day or after exercise
Ocular (ptosis, diplopia), bulbar (dysarthria, dysphagia, chewing fatigue), and proximal limb (weakness) symptoms
Pupils always spared, "myasthenic sneer"
Diagnose with the ICE PACK TEST: 80% sensitivity if prominent ptosis is present initially. Edrophonium is no longer available for diagnosis.
Symptomatic treatment with Physostigmine (quick onset, short duration of action)
Adults: 30mg TID, titrated to effect, max dose: 120mg q4hrs while awake
Children: 0.5-1mg/kg q4-6hrs, max dose: 7mg/kg per day
Rapid immunomodulating therapies: IVIG, Plasmapheresis. Takes days to work and lasts for weeks.
Myasthenic Crisis: respiratory compromise ---> Intubate, IVIG/Plasmapheresis, ICU
CNS Abscesses - Flipped Classroom led by Justin Cole, MD
Our flipped classroom topic for this month was CNS abscesses. During the flipped classroom sessions, we have a discussion as a large group about the selected topic. We cover everything from focused history and physical exams to diagnosis, management, and disposition. Here are some learning points from our discussion about CNS Abscesses:
History/Presentation: Fever, headache or back pain, focal neurologic deficit, nausea/vomiting, altered mental status, recurrent ENT infections, IVDA, recent CNS procedures, trauma, endocarditis, loss of rectal tone
Thoracic and Lumbar spine are most common places for epidural abscesses due to wider spinal canal and larger venous plexuses (no, it's not plexi)
Common pathogens:
Staphylococcus
Streptococcus
Enterobacter
Pseudomonas
Haemophilus influenzae
Neisseria
Naegleria
Workup: entire sepsis panel, inflammatory markers, image the entire back with MRI with contrast, CT myelogram if MRI is contraindicated
NO LUMBAR PUNCTURE: low yield, risk of herniation, might enter the abscess and seed other structures
Weigh the risks and benefits of waiting for culture before treating with antibiotics
Cefepime and Vancomycin, consider Gentamicin if patient had a recent procedure
Dispo: ICU
Interesting Case: Necrotizing Fasciitis - Justin Cole, MD
Signs/symptoms: skin discoloration, bullae, necrosis, ecchymosis, erythema without sharp margins, edema extending beyond erythema, foul-smelling discharge
Rapid progression with systemic symptoms
Severe pain, often out of proportion to exam
Management: sepsis workup, imaging with CT or XR, broad spectrum antibiotics (Vancomycin/Zosyn; Clindamycin has antitoxin effects against staph/strep), surgery consult for debridement
Pediatric Fever - Michael Omori, MD
Dr Omori, our Peds-EM trained faculty member, spoke to us about how to manage pediatric fever in the young infant (<3 months) and slightly older infant (>3 months). Here were his take-home points:
Below 3 months, do all the tests OR follow a clinical decision rule such as the Boston, Rochester, or Philadelphia criteria
3-36 months: consider each component based on history and physical exam.
Catheterized Urinalysis/Culture & Sensitivity (DO BOTH, transit time is shorter in young children so urinalysis is less sensitive)
Chest X-ray
CBC/Blood Cultures
Lumbar Puncture with CSF studies
Procalcitonin, CRP (if rapidly available results)
HIB and Prevnar matter, ask about immunizations
Make sure the patient has a PCP and the parents have a "CPC" (Car, phone, and a clue)
Sepsis/Meningitis, treatment trumps workup: give antibiotics quickly, even if it is before blood cultures can be drawn
Here are some other learning points that we felt were important to keep in mind:
It's easy to pull the trigger on testing in children who are obviously sick. It's harder to initiate testing on children who have a fever but are well-appearing. Find an evidence-based method of dealing with the latter and stick to it.
High fever (>39°C) has an association with occult bacteremia, as does lack of response to antipyretic
RSV bronchiolitis females have a significant likelihood of UTI coinfection
>5 days of fever: think Kawasaki Disease
References and other resources to check out:
Five pearls for the dyspneic patient with Guillain-Barre Syndrome or Myasthenia Gravis by Josh Farkas on EMCrit.org
Ice Pack Test for diagnosis of Myasthenia Gravis
"Fever Caused By Occult Infections In The 3-to-36-Month-Old Child" by Timothy G. Givens, MD in Pediatric Emergency Medicine Practice, EBMedicine
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