Category Archives: Potpourri

Cheers to a Great Year!

To the Housestaff, Faculty, Fellows, and Students,
As our year with you ends, we want to take a moment to thank you. Thank you for your dedication, your professionalism, your curiosity, and your commitment to the best quality patient care. Thank you for being expert clinicians, accomplished researchers, and outspoken advocates for your patients. Thank you for helping open a brand new hospital, for being the best recruiters in the world, and for rising to the challenge of potpourri. Thank you for supporting us, for standing by our side, for voting on the case challenges, and for reading this blog! In short, thank you, for an amazing year – we know that next year will be even better!
– Your 2014-2015 Chief Residents (Punag, John, and Kate)

Inclusion Body Myositis 101

General information

  • Most common muscle disease in patients older than 50 years. More common in white men, but can affect any group
  • Thought to be degenerative, rather than auto-immune. Associated with systemic autoimmune or connective-tissue diseases in up to 15 %

Clinical Manifestations

  • Difficulty with everyday tasks predominantly requiring the use of proximal muscles, such as getting up from a chair, climbing steps, stepping onto a curb, lifting objects, or combing their hair
  • Fine-motor movements that depend on the strength of distal muscles (especially foot extensors and finger flexors), such as buttoning a shirt, sewing, knitting, or writing, are affected fairly early in the course
  • The pharyngeal and neck-flexor muscles are often involved, causing dysphagia or fatigue and difficulty in holding up the head
  • May also progress slowly for years, and its clinical features may simulate those of limb-girdle muscular dystrophy.
  • Consider IBM in patients with polymyositis or dermatomyositis that is resistant to treatment.

Diagnostic Criteria

  • Muscle strength – myopathic muscle weakness with early involvement of the distal muscles
  • EMG – myopathic with mixed potentials
  • Muscle enzymes – normal or elevated
  • Muscle biopsy – definitive
  • Light microscopy —  endomysial inflammation, rimmed vacoules distributed around the edge, eosinophilic cytoplasmic inclusions
  • EM — granules contain membranous whorls. Filamentous inclusions in the cytoplasm or nucleus, prominent in the vicinity of the rimmed vacuoles, are pathognomonic

Treatment

  • Inclusion-body myositis is generally resistant to all therapies, and its rate of progression also appears to be unaffected by treatment.
  • Failed therapies — Steroids, MTX, Cyclophosphamide, Beta-interferon, TNF-a inhibitors, ATGAM, IVIg
  • Future possibilities
    • Alemtuzumab, a T-cell–depleting monoclonal antibody; reported slowed disease progression, improvement of strength in some patients, and reduction in endomysial inflammation
    • Follistatin, an antagonist of the myostatin pathway, has been shown to produce a dramatic increase in muscle mass in animals
    • Arimoclomol, a heat shock protein (HSP) coinducer may slow down the process of protein misfolding and aggregation

Myocardial Infarction Complicated by Heart Block

  • Acute coronary syndrome (ACS) involves rupture or erosion of a coronary plaque with exposure of the subendothelial matrix to circulating blood and subsequent platelet adhesion, platelet activation, and platelet aggregation
  • A thrombus forms, resulting in partial or complete occlusion of the lumen of the coronary artery
  • The initial ECG is nondiagnostic in up to 50% of patients presenting with chest pain, but remains a critical part of the evaluation
  • Complete heart block (CHB) may be associated with an anterior or inferior wall MI
  • High degree AV block is associated with an increase in mortality in patients with an inferior or anterior myocardial infarction
  • Complete heart block with inferior MI generally results from an intranodal lesion and isassociated with a narrow QRS complex and develops in a progressive fashion from 1st to 2nd to 3rd degree block
  • Patients with inferior MI and CHB may be resistant to atropine and its use during active ischemia may cause ventricular fibrillation!
  • Temporary transvenous pacing is recommended
  • Patients with inferior MI and CHB typically don’t need permanent pacing as the rhythm is transient and resolves within 5-7 days

Click on the link below to see an ECG of inferior MI with complete heart block!

ECG (courtesy of Life in the Fast Lane)

Milk-Alkali Syndrome 101

Below are some key points in diagnosing and managing milk-alkali-syndrome:

Triad of hypercalcemia, metabolic alkalosis, and acute kidney injury associated with the ingestion of large amounts of calcium and absorbable alkali.

  • Excessive amounts of calcium carbonate is considered 4-5 g daily
  • Originally described in association with the use of milk and sodium bicarbonate for the treatment of peptic ulcer disease
  • There may be a resurgence of this disorder due to increased calcium therapy for presenting/treating osteoporosis, more OTC calcium carbonate preparations, and use of calcium carbonate in patients with CKD to minimize secondary hyperparathyroidism
  • Among patients hospitalized with hypercalcemia, milk-alkali syndrome is the 3rd most common cause behind hyperparathyroidism and cancer
  • Pathogenesis remains uncertain as studies have shown that some patients given high amounts of alkali and calcium don’t develop milk-alkali syndrome
  • Although renal impairment is associated, it’s not a prerequisite to develop milk-alkali syndrome
  • Individual variations in the buffering capacity of bone may play role in the susceptibility to development of hypercalcemia
  • Patients at higher risk include
    • Older individuals
    • Those at risk for volume depletion (including patients on thiazide diuretics)
    • Medications that reduce GFR (ie ARB’s, ACE-I, NSAIDS)
  • Diagnosis is based upon the history of ingestion of calcium-rich medications and the exclusion of other causes of hypercalcemia
  • Treatment:
    • Stop offending agent
    • Treat with IV saline and furosemide
    • Hypocalcemia can occur transiently with rapid rise of PTH to supranormal levels which is unique to milk-alaki syndrome

(Medarov. Mayo Clin Proc. 2009 Mar; 84(3): 261–267.)

Retinal Artery Occlusion

  • General Information:
    • Considered to be a form of a stroke with similar clinical approach and management
    • Incidence is low with less than 10 in 100,00
    • Average age is 60-65 with men more commonly affected and RF of HTN, smoking and diabetes
    • Most common etiology is carotid artery atherosclerosis, especially in older patients. Other etiologies common in the elderly include cardioembolic disease, carotid artery dissections, hypercoagulable states and vascultitis
  • Clinical Manifestations:
    • Central retinal artery occlusion and branch retinal artery occlusion present with acute, painless loss of monocular vision
    • Central retinal artery occlusion: acute and profound loss of vision in one eye, often painless, can be preceded by transient monocular blindness or a stuttering, fluctutaing course
    • Branch retinal artery occlusion: acute monocular vision loss that may be restricted to part of the visual field, with less than half of patients having impaired visual acuity
  • Diagnosis:
    • On funduscopic exam with CRAO you will see a “cherry red spot” in the macula with ischemic retinal whitening due to the occlusion +/- retinal emboli.
    • For BRAO there is a sectoral pattern to the retinal opacification +/- retinal emboli.
    • Definitive diagnosis is rarely needed, but can be confirmed with fluorescein angiography
  • Treatment: OCULAR EMERGENCY
    • Can attempt occular massage, anterior chamber paracentesis, mannitol or acetazolamide can reduce IOP, vasodilator medications or hyperbaric oxygen
    • In selected patients, ophtho can do intra-arterial thrombolysis or surgical revascularization

Disseminated Histoplasmosis

  • Basic Information

    • AIDS defining illness and typically seen in HIV patients with CD4<100 cells/microL.
    • The fungus (Histoplasma capsulatum) is found in soil contaminated with bird or bat excreta and transmission occurs from inhalation of spores.
    • Thought to be endemic in Ohio, Mississippi, Caribbean, Mexico, Asia, and Central/South America.
  • Clinical Manifestations

    • Immunocompromised hosts can present with more severe symptoms: fevers, night sweats, nausea, vomiting, dyspnea.
    • 50% of AIDS patients with disseminated histoplasmosis have pulmonary involvement.
  • Diagnosis

    • Elevated LFT’s, LDH, and ferritin are commonly seen. Elevated creatinine is considered a poor prognostic factor.
    • Although the initial chest x-ray often looks normal, may see diffuse interstitialor reticulonodular infiltrates.
    • Most sensitive and specific test for suspected disseminated histoplasmosis in an HIV patient is histoplasmosis antigen detection.
    • Histoplasmosis antigen can be detected in fluids including urine, serum, cerebrospinal fluid.
  • Management

    • Rapid initiation of treatment is important and includes induction and maintenance phases. Amphotericin B is typically used for induction for 1-2 weeks. Therapy is then switched to itraconazole for consolidation and long-term suppression.
    • 2009 IDSA guidelines recommend primary prophylaxis with itraconazole for HIV patients with CD4<150.

Myxedema Coma

  • Myxedema coma is an extreme complication of hypothyroidism in which patients exhibit multiple organ abnormalities and progressive mental deterioration
  • Precipitating factors include poor adherence to daily thyroid hormone replacement therapy, stroke, heart failure, myocardial infarction, infection, metabolic disturbances, cold exposure, trauma, gastrointestinal bleeding, acidosis, and hypoglycemia
  • Multiple organ systems are affected:
    • Hypoventilation leading to hypercapnia and hypoxemia
    • Bradycardia and hypotension
    • Hyponatremia
    • Hypoglycemia
  • Two most common findings are hypothermia and mental status changes
  • Mortality rate of myxedema coma is over 20%
  • Physical exam findings: altered mentation, bradycardia, delayed reflex relaxation, dry/cool skin, myxedematous face, constipation, abdominal distension
  • If myxedema coma is suspected, the TSH and free T4 levels should be checked promptly, but is a clinical diagnosis
  • Intravenous levothyroxine has traditionally been administered, with an initial bolus of 200 to 500 micrograms followed by daily doses between 50 and 100 micrograms until transition to oral administration is feasible
  • May consider lower doses in patients with significant cardiac history to avoid cardiac irregularities
  • Concurrent treatment with high-dose glucocorticoids (such as hydrocortisone) is recommended until adrenal insufficiency is excluded and appropriate adrenal function is confirmed
  • Also treat underlying condition that may have contributed to this: infection, bleeding, hypoglycemia

Polycythemia Vera

  • General Information
    • Polycythemia
      • Defined as increase in # RBC in the peripheral blood
      • Men Hgb >18.5 or Hct >52
      • Women Hgb > 16/5 or Hct >48
    • Relative polycythemia
      • A decrease in plasma volume that elevates the Hct or Hgb
    • Absolute polycythemia
      • Primary – mutations such as polycythemia vera, idiopathic familial polycythemia, EPO R gene mutations
      • Secondary – chronic hypoxia (high altitude, smoking, cardiac shunts, pulmonary disease, sleep apnea, EPO producing tumors (RCC, HCC, pheo, uterine fibroids), other (use of EPO injection, steroids, blood doping)
  • Symptoms
    • Indicating the hyperviscosity: chest pain, abd pain, HA, change in vision or mentation
    • Indicating polycythemia vera: post bath pruritis, erthromelalgia, gout , arterial or venous thromboses
  • Diagnosis
    • Repeat testing to avoid testing transient increases
    • History and physical considering the prior diagnoses listed, the most common cause of polycythemia is hypoxia 2/2 pulmonary disease
    • Pulse ox and ABG, CBC, UA, LFTs, CXR
    • If etiology is unclear, consider checking EPO and JAKPCV
  • Management
    • Phlebotomy: often to a goal hct below 45 for men or 42 for women.
    • Low dose ASA to reduce thrombotic complications
    • Cytoreductive therapy: i.e. hydroxyurea
    • Other therapies:
      • Interferon
      • Anagrelide (inhibits platelet maturation): PCV with secondary thrombocytosis
      • Erlotinib
      • Selective JAK2 inhibitors are being investigated

HSV Keratitis

Epidemiology

  • HSV keratitis (HSK) is the most common infectious cause of unilateral blindness in the developed world.
  • In the United States alone, there are approximately 20,000 new cases per year.

Etiology

  • Ocular herpetic disease is more frequently caused by HSV I, which is presumed to gain access to the cornea via direct contact or via the trigeminal nerve from oral infection.

Clinical Manifestations

  • Typically, patients with HSV keratitis present with blurry vision, extreme photophobia, pain, redness, and tearing.
  • Primary ocular HSV presents as periocular and eyelid vesicles, acute follicular conjunctivitis, and in some cases with keratoconjunctivitis.
  • Latent in the trigeminal ganglion; can reactivate anytime, particularly by stress, UV radiation, a compromised immune system, and hormonal changes
  • Recurrent HSK can ultimately lead to corneal scarring, ocular surface disease, neurotrophic keratopathy, and consequently to corneal perforation and blindness in severe cases

Diagnosis

  • Clinical dx: special attention should be paid to the presence of a preauricular lymph node, vesicular lesions on the lids or adnexa, bulbar follicles, decreased corneal sensation, and most notably the presence of epithelial dendrites on the cornea.
  • Corneal scrapings of HSV keratitis prepared with Giemsa stain may reveal the presence of intranuclear viral inclusion bodies.

Management

  • Primary HSV epithelial keratitis usually resolves spontaneously, however, treatment with antiviral medication does indeed shorten the course of the disease and may therefore reduce the long term complications of HSV.
  • Antiviral treatment: either topical therapy with trifluridine 1% eight to nine times a day or oral administration of acyclovir or valacyclovir for 10 to 14 days.

Complications

  • Corneal complications: may develop ulceration
  • Visually significant corneal scarring and irregular astigmatism.

Ophthalmology and Eye Diseases 2012:4 23–34

Digoxin Toxicity – A Practical Review

CLINICAL FEATURES

  • Acute digoxin toxicity
    • Time course: initial toxic effects of nausea and vomiting occur at 2-4 hours, peak serum levels at 6 hours and life-threatening cardiovascular complications  at 8-12h
    • GI: anorexia, nausea, vomiting, diarrhoea, abdominal pain
    • Metabolic: hyperkalaemia (early sign of significant toxicity)
    • CVS: enhanced automaticity (atrial tachycardias (e.g. flutter, AF) with AV block, VF, VT, ventricular ectopic beats), bradyarrhythmias (Conduction delays / blocks, slow or regularised AF), hypotension, shock
    • CNS: lethargy, confusion
  • Chronic digoxin toxicity
    • Typically occurs  in the context of intercurrent illness, especially with impaired renal function
    • Clinical features are a combination of toxicity and the intercurrent illness
    • Symptoms may have an insidious onset over days to weeks
    • Features include those of acute digoxin toxicity as well as visual disturbances (e.g. reduced acuity, yellow halos (xanthopsia) and altered color perception (chromatopsia))

DIAGNOSIS

  • Urgent K level, creatinine
  • Serum digoxin level –  a steady state level 6 or more hours after the last dose; levels can be misleading as levels near the therapeutic range (0.6-1.3 nmol/L) correlate poorly with severity of intoxication
  • ECG

MANAGEMENT

  • ACUTE DIGOXIN TOXICITY
    • Digoxin-induced cardiotoxicity is refractory to standard measures
      • Bradyarrhythmias
        • Digibind is the definitive treatment
        • Atropine
        • Epinephrine (but may aggravate cardiac irritability)
        • Pacing (rarely effective)
      • Tachyarrhythmias
        • Digibind is the definitive treatment
        • MgSO4as an adjunctive measure
        • Often refractory to cardioversion
    • Hyperkalemia: Insulin and glucose, bicarbonate Calciumis traditionally contra-indicated due to the risk of precipitating a ‘stone heart’.
    • Activated charcoal if the patient presents <1h post-ingestion and not vomiting (unlikely to prevent severe toxicity in large ingestions)
  • CHRONIC DIGOXIN TOXICITY
    • Resuscitation as for acute digoxin toxicity
    • Renal replacement therapy may be indicated in the context of renal failure and hyperkalemia
    • Digibind!