UMEM Educational Pearls

With the cooler weather on us all our favorite viral infections will start to appear.  Included in this is the "slapped - cheek disease" Erythema infectiosum. 

Erythema Infectiosum

• An acute viral illness caused by parvovirus B-19
• Usually is seen in the winter and spring months
• Presents with mild fever, itching, headache, and arthralgias
• Usually have an erythematous, erysipeloid rash on the cheeks (slapped look) and a reticular rash (lace-like) on the arms
• No test are needed
• Management is supportive
• Children with chronic hemolytic anemias can develop an aplastic crisis from this infection

 Olanzapine (Zyprexa)

This is an atypical antipsychotic that gained popularity because it caused less sedation and fewer extrapyramidal effects. However, there are many other adverse effects that need to be emphasized. Some of these may contribute to a patient's condition in the ED:

• Hyperglycemia: has been reported to even cause hyperglycemic hyperosmolar nonketotic coma as well as DKA in patients that were not diabetic prior to initiation of olanzapine.
• Anticholinergic: one of the most anticholinergic antipsychotics, watch for polypharmacy. Perhaps the patients urinary retention and mild confusion is due to the many anticholinergic medications the patient is taking.
• Serotonin Syndrome: again a problem with polypharmacy and in overdose.

• There is mounting evidence in favor of effectively treating migraine headaches with antiemetic dopamine antagonists such as metoclopramide (Reglan) and prochlorperazine (Compazine) as primary parenteral management.

• Diphenhydramine (Benadryl) can be administered simultaneously with such agents to prevent akathisia and dystonic reactions.

• Apart from the prophylactic effects of diphenhydramine, it may also play a synergistic role is actually treating the symptoms.

• A recent study (Friedman, et al) showed no significant difference in the efficacy or adverse events of treating migraine with 20 mg of metoclopramide plus 25 mg of diphenhydramine versus 10 mg of prochlorperazine plus 25 mg of diphenhydramine, although there was an insignificant trend in favor of prochlorperazine lowering the pain score to a greater degree.

• Note that the 20 mg dose of metoclopramide is higher than what is traditionally used in most emergency departments, but escalating the dose of up to 20 mg over a few hours may be more efficacious (the slower the administration and the simultaneous use of diphenhydramine decreases risk of dystonic reactions).

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 Influenza and the Critically Ill

• It is that time of year again to be vigilant for cases of influenza
• Influenza is not benign and causes > 40,000 deaths per year and is the 7th leading cause of death in the US
• In the critically ill, the most severe disease occurs in patients > 65 and those with underlying cardiopulmonary disease
• Critically ill patients with influenza can present with fever, cough, bilateral interstitial infiltrates, hypoxemia, and leukopenia
• Other serious complications include myocarditis, encephalitis, and Reye syndrome
• Amantadine and rimantadine should no longer be used, as the resistance has risen to > 90% in some populations
• Oseltamivir (PO) and zanamivir (powder/inhalation) are the approved neuraminidase inhibitors; both decrease the severity and duration of illness; should be given as early as possible, preferably within 36 hours

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Anticoagulation with Heparin-How to Reverse?

So you just started Heparin on that ACS patient? Just bolused the patient in room 12 with the large PE with a slug of Heparin? The nurse tells you that one of them just vomited blood and the other just had a large bloody bowel movement. What to do, oh, what to do?

How to reverse Heparin...use Protamine:

• Protamine is obtained from the sperm of salmon and other species of fish....glad you know that now?
• Given IV, it binds to Heparin (Unfractionated Heparin) and inactivates it
• Administer Protamine (IV) at a dose of 1 mg for every 100 Units of Heparin given within the last four hours. Max dose 50 mg of Protamine. May give more than 50 mg, but use caution as may lead to bleeding
• If the dose of Protamine is exceeded, patients may bleed. Protamine is actually an anticoagulant. 
• Give slowly over 10 minutes as may cause anaphylactoid reaction
• Can use to reverse LMWH as well: 1mg Protamine per 1 mg of LMWH (Lovenox)

Amiodarone-induced hypothyroidism is well-reported and should be considered anytime a patient that chronically takes amiodarone presents with hypothyroid symptoms, including decompensated CHF, decreased mental status, or myxedema coma (e.g. bradycardia, hypotension, hypothermia). 

Other drugs that have been implicated in producing hypothyroidism include lithium, iodine, iodinated contrast, and sulfonamides.

Bisphenol A (BPA) is found in epoxy resins that line common food and beverage materials. There has been concern that this compound, like phthalates, may be causing harm through chronic low exposure. An epidemiologic study was performed and published in JAMA that has raised this question. Amazingly, the study did find that:

• Higher urinary BPA levels correlated with an increase incidence of: NIDDM, CAD and elevated liver enzymes
• Mechanism may be an estrogen effect, disruption of Beta-islet cell function and even obesity promoting effects
• Study was strictly epidemiologic but raises a serious public health concern that you will see in the news more

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-- Tourette Syndrome (TS) is an inherited neurological disorder characterized by repetitive involuntary movements and uncontrollable vocal sounds called tics.
-- Underlying defect is unknown; however, research suggests that it could be caused by abnormalities in serotonin and dopamine activity within the basal ganglia.
-- Associated behavioral problems include OCD, ADHD, anxiety, and depression.
 

Diagnostic criteria:

Can You Rely on Your Clinical Impression to Exclude SBP?

• SBP is an important can't miss diagnosis, as the mortality rate even for treated patients is approximately 20%
• The incidence of SBP ranges from 2.5% (clinic setting) to 12% of all patients admitted with decompensated cirrhosis
• SBP is diagnosed by a neutrophil count > 250 or a positive ascitic fluid culture obtained via paracentesis

• Can our clinical impression exclude SBP without performing a paracentesis? Unfortunately, the answer is NO.
• Sensitivity of physician clinical impression is just about 75%, with a specificity of 34%
• Fever is uncommon in patients with SBP (sensitivity as low as 17%)
• Take Home Point: only a diagnostic paracentesis can reliably exclude SBP in patients admitted for decompensated cirrhosis

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Cerebral Venous Sinus Thrombosis (CVST)

An uncommon but very serious entity that leads to three distinct types of presentations:

• Headache
• Seizures
• Stroke

Caused by thrombosis of one of the intracerebral venous sinuses (most commonly the transverse sinus) The major risk factor is hypercoagulable disease. May be the underlying cause of a majority of cases of idiopathic intracranial hypertension.

When to suspect:

• Headache with negative CT, negative LP, but high opening pressure
• In any patient with new onset idiopathic intracranial hypertension (i.e. pseudotumor cerebri). Can't be formally diagnosed without a negative MRI.
• Stroke syndrome that doesn't quite fit. May see bilateral infarcts in the posterior regions. These are actually venous infarcts secondary to the sinus thrombosis.

Diagnosis:

• Just like a lot of other things in medicine, "If you don't think about it, you can't diagnose it."
• 1 in 3 head CT scans will be normal
• MRI with MRV (venous phase) is the diagnostic standard

Treat:

• Anticoagulation with heparin then warfarin

An estimated 20-30% of patients with ACS end up having no identifiable culprit lesion on angiography. Almost half of these patients have inducible coronary spasm. Although these patients have a good outcome, they also have a tendency to return to the hospital for frequent re-evaluations. Evaluation for and treatment of spasm can improve the quality of life for these patients and also to decrease re-visits.

When patients with reports of "clean" coronaries return to the ED with a concerning presentation for ACS, one of the considerations should be coronary spasm. Consider prompting the primary care physician or admitting team to look into this possibility, as it may result in a reduction in recurrent ED visits.

Severe Hypothyroidism or Myxedema Coma

• Mortality rate has been as high as 80% now 15-20% with aggressive treatment
• Some common symptoms are:
  • Constipation
  • Depression
  • Lethargy
  • Dry, Brittle hair or Alopecia
  • Weight Gain
  • Cold Intolerance
  • Weight Gain
• Treatment consists of:
  • Rule out aggravating cause (i.e.: infection)
  • Start IV levothyroxine dosing
    • Initial dose 400-500 mcg (Helps to saturate the thyroid receptors)
    • Daily dose 100 mcg/day
  • Consider starting Dexamethasone or doing a Cortisol stimulation test
    • Patients may also have adrenal insufficiency from primary pituitary failure or may have secondary adrenal suppression due to the severe hypothyroidism.  If dexamethasone is not provided they may develop severe adrenal insufficiency once you kick start their metabolism.

Pediatric Discitis is an intervertebral disc infection due to hematogenous spread to vascular channels in cartilage that disappear later in life.  In 1/3 of patients it is caused by S. aureus.

Presenting Features

• age <2.5 years (75%) 
• Refuse or difficult to walk  (56%)
• Back/neck pain (25-45%) ( 100%>3years)
• Hx of fever (28-47%)
• lumbaosacral area (78-82%)
• Mean ESR 39-42
• WBC> 10,500 (50%)
• Abnormal MRI 90-100 %

Management is to exclude more severe disease (osteomylelitis,abscess, tumor) and antibiotic use is debatable.  Remember children this age rarely complain of back pain. 

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Clinical Manifestations in relation to lead level in children:

• > 70 - 100 mcg/dL: Encephalopathy, increased ICP, anemia, vomiting
• 50 - 70 mcg/dL: Irritable, difficult child, abdominal pain, anorexia
• >10 mcg/dL: often asymptomatic, may develop impaired cognition, behavior, impaired fine-motor coordination, hearing and growth

Tension gastrothorax?

• Tension gastrothorax is a life threatening condition characterized by herniation of the stomach through a defect in the diaphragm with compression of the mediastinal contents
• Although many cases occur in pediatric patients (secondary to congenital defects), adults with a history of diaphragmatic injury are at risk (also patients with a type III or IV hiatal hernia)
• The clinical presentation is the same as a tension pneumothorax - hypotension, tachycardia, hypoxia, JVD, and decreased breath sounds
• CXR appearance can be very similar to tension pneumothorax, however, the treatment is substantially different
• Needle decompression and tube thoracostomy are contraindicated, as this may cause visceral perforation
• The treatment of choice is NGT (or OGT) decompression followed by surgical repair

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 Does Hypertension (elevated BP) Cause Headache?

This is an age old question that many of us have struggled with in the ED for many years...

Other questions include: Does elevated BP cause headaches? Do we need to scan hypertensive patients with headache just because they have a headache? At what level of BP does the BP actually cause headache? 

A few quick pearls:

• Although incredibly high BPs (diastolics above 130 mm Hg) have been correlated with headache, the general concensus is that hypertension doesn't really cause headaches. 
• At really high blood pressures (again, diastolic BP > 130-140), cerebral autoregulation breaks down and may lead to cerebral edema and headache...hypertensive encephalopathy.
• Elevated systolic BP may actually be protective for developing headaches
• CT scanning the hypertensive patient with a headache is not warranted a lot of the time, unless the patient has a neuro deficit, or if the headache was acute onset or associated with other findings of hypertensive encephalopathy.
• Patients with HTN are as likely to have a headache in the ED as non-hypertensive patients

Severe emotional stress is well-reported to produce an unusual transient cardiomyopathy that mimics cardiac ischemia or infarction on ECG as well as biomarker testing. On angiography, the coronaries are often clean. The ventriculogram takes on an apical or mid-ventricular ballooning appearance due to akinesis. In the ED, these patients will look just like a real thrombosis-related case of ACS and they often develop cardiogenic shock. Unlike true AMI-related cardiogenic shock, these patients have an excellent prognosis...if treated aggressively early-on with supportive therapy (e.g. pressors).

Intracranial catastrophes, such as hemorrhage, ischemic stroke, and head trauma; and severe medical illnesses, such as sepsis, pheochromocytoma, and catecholamine-excess states, are also reported to produce a similar syndrome of LV dysfunction.

The takeaway points: (1) severe emotional stress can be deadly...be wary of diagnosing "anxiety" or "panic attack" without checking an ECG; (2) check an ECG early in the course of any patients with the above conditions that look sick; (3) if the ECG shows signs of severe ischemia, aggressive treatment can be life-saving.

[ref: Bybee KA, Prasad A. Stress-related cardiomyopathy syndromes. Circulation 2008;118;397-409.]

Mallet Finger:

A common injury resulting in a tear or avulsion of the extensor digitorium tendon inserting into  the base of the distal phalanx.  Occurs due to hyperflexion of the finger usually as of a esult of it getting jammed on a ball while playing sports.  Most can be treated non-surgically.

The distal phalanx must be kept in full extension for 6 to 8 weeks. This is one of the few times that the finger should not be splinted in the position of function.

Make sure that patient is informed that if they remove the splint and flex their finger the 6 to 8 week healing window will be reset to day 0.  These patients should not be doing ROM exercises and must wear the splint full time.

Popsicle or cold panniculitis is an inflammation of the subcutaneous fat after prolonged exposure to cold.  It is thought to occur more often in infants and young children because they have a higher percentage of saturated fatty acids than older children and adults.  Pediatric patients may present to you to be evaluated/ruled out for abuse by social workers, schools, or police and if you have the correct history it is easy to dispo quickly.

Clinical Features of Popsicle Panniculitis

• Absence of systemic signs
• Minimal pain, with or without
• Skin is red to purplish, indurated, may have discrete nodules or plaques
• perioral location for popsicles, but may occur at any other area of skin exposure
• resolves in 2-3 weeks without scarring
• hyperpigmentation may persist
• arises within hours to to 1-2 days after exposure to a cold object

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Several antihypertensive agents raise intracranial pressure. Normal cerebral blood flow (CBF) is constant within normal cerebral perfusion pressure (CPP) ranges, recalling that CPP=MAP-ICP.

If CPP is outside the range in which autoregulation occurs, e.g. due to a structural lesion, ischemic stroke, or head trauma, CBF decreases and can adversely affect the patient.

• Nitroprusside
  • Vasodilates both cerebral arteries and veins, increasing ICP
  • Inhibits the normal vasoconstrictive response to hypocapnia
• Nitroglycerin
  • Causes cerebral venodilation, increasing ICP
  • Impairs vasodilatory response to hypercapnia
• Hydralazine (varying effects)
  • Vasodilates cerebral arteries > cerebral veins
  • Impairs cerebral autoregulation
• Nicardipine
  • Other calcium channel blockers increase ICP by vasodilating arteries
  • Has been used to treat vasospasm in SAH
  • Increases cerebral blood flow in patients with SAH and acute stroke

In patients with ischemic stroke or intracerebral pathology, labetalol or esmolol may be used to lower blood pressure without raising ICP. Nicardipine is recommended for use in patients with ischemic stroke or SAH but not in patients with brain injury

If the patient has NO structural abnormalities, but has hypertensive encephalopathy, nitroglycerin, nitroprusside, labetalol, esmolol, or nicardipine may be used.

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