Archive | December, 2015

Vertebral Osteomyelitis/Discitis

23 Dec

submitted by Amit Kumar, M.D.

QUICK HITS:

3 main mechanisms of infection:

  • Hematogenous spread
  • direct inoculation (trauma, spinal surgeries/procedures)
  • contiguous spread from adjacent tissues

 

Culprit:

  • Staph aureus (>50%)
  • enteric gram-neg bacilli (following GU procedures)
  • psuedomonas/candida (often due to IV sepsis or IVDU)
  • group B strep (esp. in diabetics)

Signs & symptoms:

  • Localized spinal pain
  • leukocytosis
  • elevated ESR/CRP
  • fever
  • new radicular symptoms

Diagnostic strategies: Blood culture, MRI (most sensitive radiologic technique), biopsy (open/CT guided)

Differentials: Spinal epidural abscess, psoas abscess, herniated disc, spinal metastasis, vertebral compression fracture

Treatment: Pain control, ANTIBIOTICS (empiric followed by pathogen-directed. Routinely for minimum of 6 weeks), surgery (indications: neuro deficits, abscess needing drainage, cord compression)

Complications:

  • Posterior extension leading to epidural/subdural abscess or meningitis.
  • Anterolateral extension leading to paravertebral/psoas abscess.

***Picture: High signal is T2-weighted MRI at the disc and adjacent vertebral body compatible with diagnosis

Sources:

http://www.uptodate.com/contents/vertebral-osteomyelitis-and-discitis-in-adults?source=search_result&search=discitis&selectedTitle=1~51

http://www.med.harvard.edu/jpnm/tf03_04/jan6/writeup.html

-Picture:http://www.med.harvard.edu/jpnm/tf03_04/jan6/MRI.gif

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picture of the day: orbital compartment syndrome

18 Dec

via this EM Ireland talk on eye injuries:

hopefully, you’ll be able to see some signs clinically (e.g. proptosis, pain with EOM) if you’re worried about retro-orbital hematoma causing orbital compartment syndrome, but if you’re on the fence, you might see this on CT:

orbital

 

signs of orbital compartment syndrome on CT:

  • loss of contour of globe
  • tenting of the globe
  • proptosis

 

References: EM Ireland post

the “JR knot” for securing central lines

14 Dec

via last month’s Procedural Pause from Dr. James Roberts:

traditionally we’re taught to thread a stitch through the central line base piece as we take the bite.

NEXT TIME…

tie your knot first, then thread through the central line piece and tie it down.

Step 1: suture a knot on your patient

jr suture 1

Step 2: thread it through the central line anchor piece

jr suture 2

Step 3: tie another knot.  it all comes together.

jr suture 3

Simple enough, logical, easy to do.

 

Add it to the toolbox.

 

References: procedural pause video

 

MYASTHENIA GRAVIS (quick pearls)

8 Dec

Submitted by Amit Kumar, M.D.m_jpg0420f1

Quick Pearls:

Pathology: Auto-antibodies against ACh post-synaptic receptors

Common symptoms:

  • Ocular (ptsosis, diplopia),
  • bulbar (fatigable chewing, dysarthria, dysphagia),
  • loss of facial expessions,
  • neck/proximal limb weakness,
  • respiratory failure leading to myasthenia crisis (often tested via negative inspiratory force and vital capacity- NIF/VC)
  • Concerning if NIF and VC approach 25cmH2O and 15mg/kg body weight respectively.

 

Diagnosis:

-Bedside tests (higher risk for False+): Edrophonium “tensilon” test (acetylcholinesterase), ice-pack test

-Serum tests: ACh-R antibodies (more common), muscle-specific receptor tyrosine kinase (MuSK) antibodies

-Other: Repetitive nerve stimulation –> Fatigable

Complications:

-Thymic hyperplasia (85%), thymoma (15%). Prophylactic thymectomy recommended for <60y.

autoimmune thyroid dx (3-8%)

Treatment:

-Pyridostigmine (anticholinesterase)

-Chronic immunotherapies (glucocorticoids, azathioprine, cyclosporin, etc.)

-Rapid immunotherapies: plasmaphresis (usually every other day for total of 5 sessions), IVIG (total dose of IVIG is 2 g/kg, usually over 2-5 days)

Fun fact:

MANY medications are contraindicated in MG:
-Certain Antibiotics: Macrolides (Azithromycin, Erythromycin), Gentamicin, Kanamycin, Neomycin, Streptomycin, Tobramycin; Fluoroquinolones: Ciprofloxacin
-Cardiovascular drugs: Quinidine, Procainamide, Quinine Calcium channel blockers, Beta-blockers
-Neuromuscular Blocking Agents: Succinylcholine, d-tubocurarine or Any other neuromuscular blocking agent
-Narcotics: Meperidine, Morphine
-Any medication with the potential to suppress respiratory drive
Other medications: Iodinated contrast agents, Magnesium Preparations, Especially intravenous Magnesium but also PO such as Maalox, Steroids, Botulinum Toxin

***A good rule-of-thumb in generalized MG is to assume that any medication may exacerbate MG and to watch for worsening following the introduction of a new medication.

References:

  1.  Pal S, Sanyal D. Jaw muscle weakness: a differential indicator of neuromuscular weakness–preliminary observations. Muscle Nerve 2011; 43:807.<http://www.uptodate.com/contents/clinical-manifestations-of-myasthenia-gravis/abstract/20>
  2.  Lennon VA. Serologic profile of myasthenia gravis and distinction from the Lambert-Eaton myasthenic syndrome. Neurology 1997; 48:S23.<http://www.uptodate.com/contents/diagnosis-of-myasthenia-gravis/abstract/9>?
  3.  http://www.uptodate.com/contents/tests-of-respiratory-muscle-strength?source=search_result&search=NIF%2FVC+%2B+myasthenia+gravis&selectedTitle=1~150?
  4.  September 2015 EMRAP- Drugs not to use in Myasthenia Gravis

5. picture

Erythema Multiforme

4 Dec

Submitted by Amit Kumar. 

QUICK PEARLS:652397_m

*Acute immune mediated, distinctive target-like lesions

*Erythema multiforme “major”: EM with mucosal involvement (ocular, oral, genital)

em_21312922303581
*Population: Mostly 20-40yo, M > F

*Precipitators: #1 = infection (HSV most common, mycoplasma in children).

Other causes: medications, malignancy, autoimmune disease, immunizations, radiation, sarcoidosis, and menstruation

*Commonly confused with Stevens Johnson Syndrome (<10% body surface area) and Toxic Epidermal Necrolysis (>30% BSA): Also targetoid lesions with mucosal involvement, but mostly drug-induced

*Evaluation & diagnosis:

  • Skin punch biopsy (to check for HSV antigens in potential subclinical case, differentiate from autoimmune bullous diseases such as pemphigus or pemphigoid)
  • sampling of perioral lesions (for HSV PCR/Tzanck smear),
  • serologic tests for M. pneumoniae,
  • check labs (CBC, ESR, LFTs),
  • wound culture (if concerned for secondary infection)

*Treatment:

  • Acyclovir 400mg q4h (if HSV), Prednisone 60mg daily followed by ~two week taper.
  • Symptomatic treatment: Benadryl, ELTA cream
  • Consult ophthalmology for ocular involvement
  • Monitor nutrition (if compromised due to oral involvement)
  • Pain control
  • Prophylaxis: Acyclovir 400mg BID (for HSV)

References:

http://www.uptodate.com/contents/pathogenesis-clinical-features-and-diagnosis-of-erythema-multiforme?source=search_result&search=Erythema+multiforme&selectedTitle=1~150; picture 1, picture 2