UMEM Educational Pearls

Low QRS voltage (LV) on the ECG is generally defined as the presence of QRS amplitudes which are < 0.5 mV (5 mm) in all of the limb leads and < 1.0 mV (10 mm) in all of the precordial leads. This is a fairly tight definition and for practical purposes, the definition is sometimes expanded to include patients with the sum of QRS amplitudes in leads I, III, and III adding up to < 15 mm; OR the sum of the QRS amplitudes in leads V1, V2, and V3 adding up to < 30 mm. Causes of LV can be divided into two major groups: (1) deficiency of the heart's generated potentials, or "cardiac causes," and (2) attenuating influences outside the heart, or "extracardiac causes." Cardiac causes include: cardiomyopathies (which can sometimes be caused by multiple prior MIs), infiltrative cardiac diseases (e.g. amyloid), severe hypothermia, and inflammatory diseases of the heart due to chemicals or infections (incl. myocarditis). Extracardiac causes include: large pericardial or pleural effusions, obesity, COPD (esp. if a barrel chest is present), pneumothorax and other forms of barotrauma (esp. left-sided).

A maisonneuve fracture is a fracture dislocation resulting from external rotational forces to ankle -- through interosseous ligament to fibula.

• Proximal fibula fracture - from external rotational forces (spiral/oblique)
• Ankle components can include any of the following:
  • medial maleolus avulsion fx or deltoid ligament rupture
  • anterior talofibular ligament rupture
  • interosseous ligament rupture
  • posterior malleolar fracture

If stability is questionable, orthopedic evaluation under anesthesia is required. Additionally always consider compartment syndrome. Do not rely on Kanduval's signs (pain, paraesthesia, pallor, poikilothermia, pulselessness) - "... with the exception of pain and paraesthesia, these traditional signs are not reliable." Emergent orthopedic consultation and compartment pressure assessment should be performed. (see attached photos)

 

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This is a psychoactive herb which can induce strong dissociative effects by stimulation of the kappa receptor. It has become increasingly well known and available in modern culture, and popularized by YouTube Salvia (also known as Sage, Diviner's Sage, Magic Mint, or Sally D) is usually smoked, but can be chewed or ingested.

The high it produces is very intense, but lasts only approximately 10 minutes. Currently many states have enacted legislation against it, including Fla, IL, KA, MI, MO, ND, OK and VA, but it is available over the internet.

  

The following video demonstrates clinical effects of drug.
Although it is amusing, this is not meant to condone use.

(if you can not view the embeded video here is the link)

http://www.youtube.com/watch?v=w6dgXX0ytSo

• Chiari Malformations are congenital abnormalities wherein the cerebellum downwardly displaces into the spinal canal.
• This results in an increase in pressure and subsequent obstruction of CSF flow.
• Common symptoms associated with Chiari Malformations include:

              -  vertigo

              -  headache

              -  muscle weakness

              -  coordination abnormalities

              -  gait abnormalities

              -  visual abnormalities

Pulmonary Embolism Rule Out Critieria (PERC) A brief reminder about the PERC rules... Use of the PERC (Pulmonary Embolism Rule-out Criteria) rule can significantly decrease work-up for pulmonary embolism. To apply this rule, the clinician must first use clinical gestalt to classify the patient as low risk. The PERC rule, which consists of eight clinical criteria including history, physical and vital signs, can then be used. If both of these criteria are met, then there is less than a 2 percent risk that this patient has a PE and no further work-up is needed. PERC Rule: Age < 50 years Pulse < 100 bpm SaO2 > 94% No unilateral leg swelling No hemoptysis No recent trauma or surgery No prior PE or DVT No hormone use This rule has now been validated in a large, multicenter trial. Bottom line: If you walk out of the room and your clinical gestalt is "no PE" and the PERC rule is negative, there is a <2% chance of pulmonary embolism (<2% probability, by the way, is what many PE experts consider the test threshold)

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Auto-PEEP in the non-COPD patient

• In previous pearls we have discussed the concept of auto-peep in patients with expiratory flow limitation (asthma and COPD)
• Unexpected auto-peep can also occur in up to 35% of patients without asthma or COPD
• In these patients, auto-PEEP typically occurs with high minute ventilations (> 20 L/min) with shortened exhalation times or if exhalation is blocked (blocked ETT, exhalation valve, or PEEP valve)
• Recall that auto-PEEP increases the work of breathing, worsens gas exchange, and can cause hemodynamic compromise 
• Treatment of auto-PEEP can be as follows:
  • Change ventilator settings
    • increase expiratory time
    • decrease respiratory rate
    • decrease tidal volume
  • Reduce ventilatory demand
    • reduce anxiety, pain, fever with sedatives
  • Reduce flow resistance
    • large-bore ETT
    • frequent suctioning
  • Apply external PEEP

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The classic risk factors for coronary artery disease (e.g. hypertension, diabetes, smoking, etc.) are helpful at predicting the long-term risk of CAD, but they have limited utility at predicting whether a patient with acute symptoms is having an acute coronary syndrome or not. In one recent study of > 800 patients with suspected cardiac chest pain, 12% of patients with NO cardiac risk factors ruled-in for acute MI.

Never rule out ACS in a patient purely based on the absence of traditional cardiac risk factors!

[Body R, McDowell G, Carley S, et al. Do risk factors for chronic coronary heart disease help diagnose acute myocardial infarction in the Emergency Department? Resuscitation 2008;79:41-45.]

High altitude illnesses is typically called Acute mountain sickness (AMS) and is associated with two major complications high altitude pulmonary edema (HAPE) and high altitude cerebral edema (HACE).

Symptoms associated with AMS are headache, fatigue, nausea and vomiting, anorexia and insomia. Cough, Cyanosis, hypoxia, and dyspnea are associated with HAPE.  HACE is associated with progressive neurologic symptoms and can lead to ataxia and coma.

Factors that increase your risk for altitude illnesses are:

• Rate of ascent
• Elevation obtained
• Exertion on arrival to elevation
• Duration at that altitude
• Recent URI
• Previous symptoms of AMS

How do we know if we really need to put all those red eyes sent in from daycare centers and schools on antibiotics? The following study shows us why.

Bacterial Conjunctivitis in Children

• Prospective study in a children’s hospital ED
• Conjunctival swabs for culture were obtained from patients aged 1 mo - 18 yrs presenting with red or pink eye and/or the diagnosis of conjunctivitis
• 111 patients enrolled over one year
• Mean age of 33.2 mos, 55% male
• 87 patients (78%) had positive bacterial cultures
  • Nontypeable H influenzae = 82%
  • S pneumoniae = 16%
  • Staphylococcus aureus = 2.2%
• The combination of a history of gluey or sticky eyelids and the physical finding of mucoid or purulent discharge had a post-test probability of 96% that the infection was bacterial.(So when both these are present you definitely should treat)
• And since the majority of these children (78%) had positive cultures even if they only had a pink eye it is reasonable to use empirical ophthalmic antibiotic therapy in children who present with the complaint of a pink eye.

 

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Methylenedioxymethamphetamine (MDMA) or "Ecstasy"

A designer club drug that has been classified as a "hallucinogenic" amphetamine though it does not cause visual hallucinations like are reported with LSD. It has many of the sympathomimetic effects like other amphetamines but its main mechanism of action which both causes the euphoria and toxicity is serotonin agonism. Since Anti-diuretic hormone is released by the hypothalamus under the direct regulation of serotonin, there is a transient but dangerous episode of Syndrome of Inappropriate ADH (SIADH). Combined with the club culture and fear of dehydration while taking MDMA, patients ingest MDMA concomitantly with free water through the night further exacerbating the hyponatremia. The time sequence of events for these patient is (women appear genetically predisposed to this phenomena):

• Friday Night: Ingestion of MDMA (even one pill is enough) +/- free water
• Saturday Morning: headache, nausea, vomiting
• Saturday Afternoon: (Realizes its not a hangover) patient becomes confused progressing to unresponsive and eventually seizures
• Saturday Evening: Presents to ED with seizures

Treatment: Fluid restriction - this is the one time that the 1L NS Bolus can kill a patient with cerebral edema. If you must give fluid give 3% NaCl if there is symptomatic hyponatremia. Remember the patient has dropped their sodium in about 24 hours so you can replenish in about the same time quite safely and even faster in severe cases. Treated correctly, patients improve rapidly - within 24-48 hours. Read a great case report in the reference below.

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• It is crucial to be familiar with and use  the NIH Stroke Scale (NIHSS) to objectively describe the extent of a stroke, in a language universal to all physicians, particularly our neurology colleagues.
• This validated tool consists of 15 items and the scale ranges from 0-42.  The higher the number, the worst the stroke.
• The NIHSS does not have to be memorized, but rather accessible for reference when needed.
• Studies have validated an abbreviated, 5-item NIHSS that has the same predictive performance as the 15-item scale.  This scale ranges from 0-16.
• While this abbreviated scale was created primarily for use in the prehospital setting, it can certainly be performed in the ED prior to rushing the patient off the CT for a head scan, in order to provide your neurologist with some objective information in a timely fashion.
• The NIHSS-5 assesses the following functions, in decreasing order of importance in terms of prognosis:

              --  motor function (right leg)

              --  motor function (left leg)

              --  gaze

              --  visual fields

              --  language

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Ventilator Therapy for ED Patients with ARDS

• As we manage critically ill patients for longer periods of time, it is likely that many of us will manage patients who develop ARDS
• Current mortality for patients with ARDS ranges from 30-40%
• ED treatment for patients with ARDS includes treating the inciting event, supportive critical care, and ventilator management
• Current ventilator management in patients with ARDS includes:
  • avoiding alveolar overdistention (tidal volumes of 6 ml/kg)
  • maintaining F_iO₂ < 60% (mitigates oxygen toxicitty)
  • PEEP to prevent alveolar derecruitment (levels of 10-15 cm H₂O)
  • permissive hypercapnea

Reversal of Warfarin

Reversal of Warfarin can be accomplished by administering any of the following:

• Fresh Frozen Plasma (traditional reversal agent)
• Vitamin K (po, sub q, or IV)
• Prothrombin Complex Concentrates (PCC)-not yet available for use in the US (yet)

A few pearls:

• It doesn't take many units of FFP to lower someone's INR
• Don't forget volume considerations if you use FFP
• Vit K is pretty well tolerated but some patients will have an allergic reaction (more common with IV administration)
• These medications in general will be used for life-threatening bleeding (GI, CNS bleeds, retroperitoneal bleeds, etc)
• Prothrombin Complex Concentrates-rich in factors 2,7,9, and 10...perfect drug since Warfarin depletes these factors
• PCC associated with some increased thrombosis

 

Syncope patients are often misdiagnosed as having a seizure. Some factors favoring true syncope:
1. Preceding nausea or diaphoreses
2. Oriented (not confused) upon waking (no post-ictal period).
3. Age > 45
4. Prolonged sitting or standing before episode
5. History of CHF or CAD

Factors favoring seizures:
1. History of seizure disorder
2. Tongue biting
3. Confusion upon waking
4. Loss of consciousness > 5 min
5. Age < 45
6. Preceding aura
7. Observed unusual posturing, jerking, or head turning during episode

Management of Felons

• An abscess of distal finger that involves the pulp. 
• A difficult infection to treat due to fibrous septa that divide the pulp into multiple small compartments. 
• These septa run from the periosteum to the skin increasing the risk of osteomyelitis
• Patients typically present with a lot of pain, redness, and swelling.
• Typically triggered by a puncture wound (i.e.: splinter)
• Incision and Drainage can result in a:
  
  • anesthetic finger tip
  • unstable finger pad
  • neuroma
• If you are going to drain one it is recommended that you do a volar longitudinal incision down the middle of the finger pad or a high lateral incision. 
• The high lateral incision should be at about 5 mm below the nail plate border. This distance should allow for avoiding the more volar neurovascular structures.

For good photos of the incision technique please visit the reference article listed.

Clark, DC. Common Acute Hand Infections. Am Fam Physician 2003;68:2167-76

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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)