UMEM Educational Pearls - Misc

 Wernicke's Encephalopathy

Wernicke's encephalopathy, considered a unique complication of alcoholism, is also seen in malnourished patients, bariatric surgery patients, and patients who have undergone bone marrow transplantation.

Some pearls about Wernicke's encephalopathy:

• The classic triad of confusion, ataxia, and opthalmoplegia is seen in only about 10-15% of cases
• The diagnosis is made before death in only about 10_15% of cases
• Most authorities on the disease have suggested that opthalmoplegia be replaced by ocular, since many ocular findings may be seen in these patients (nystagmus, retinal hemorhages, cranial nerve palsies)
• Essentially any alcoholic who presents with confusion (ever see these patients in your ED?) could have the disease, so give Thiamine liberally when the patient arrives. 
• It is a myth that administration of thiamine before glucose will precipitate Wernicke's. This dogma is based on a case series of 4 patients from the Irish Journal of Medical Sciences. 

Hypothermia Pearls:

• Lidocaine is generally ineffective in preventing ventricular arrhythmias, as is cardiac pacing or atropine to increase the heart rate.
• Should the patient fully arrest be prepared to perform CPR for a long time.  If your ED does not have a automatic CPR device consider calling your local fire department or ambulance service as they might have one that can be loaned to your department.
• Warm fluids, heated blankets and heat lamps will typically increase a patients temperature about 1' C an hour.
• Gastric lavage, peritoneal lavage and heated IV fluids can warm as much as 3' an hour.
• To rewarm quickly as high as 18'C an hour requires cardiac bypass or thoracic lavage.

Finally, remember to monitor the patient closely when you first start rewarming as this can induce cardiac arrest.  This is thought to occur as colder peripherial blood returns to the central circulation as peripherial veins and arteries dilated from the warm fluid.

Reimburshment Pearls:

Often charts are down coded as it is not clear from the documentation that your medical decision making was complex.

For instance, if your final diagnosis is GERD, and you do not document that you were also concerned about angina or a pneumothorax your level 5 chart could be coded as a level 3, since the final diganosis does not seem that complex.  In order to prevent this document:

• Your differential diagnosis and ideally why you were concerned about them
• Instead of just checking a box stating that you reviewed old records take 5 seconds to summarize their last visit.  (i.e.: Admitted in May for CHF exacarebation, EF 50% by Echo, discharge on lasix).  This helps the coders prove that you looked at the chart and gives you 2 points for medical decision making.
• Document the response or initial lack of response to therapy. (i.e.: Asthmatics might get discharged home and still qualify for critical care time or a level 5 chart if you document how they initially responded to nebulizers and it was the magnesium that finally broke the cycle.)

I realize that when you are busy this might be the last thing on your mind, but the difference between a level III chart and a level V chart is about $100, and the only additional work is the 3 minutes it would take to document what you did for the patient.

More to come...

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This week's monday pearl is from our very own Azher Merchant....who recently gave an excellent talk on the risks of radiation.

Be afraid....be very afraid....

Radiation Risk:
Risk is based on acute exposure and is extrapolated largely from atomic bomb survivors.
Effective radiation dose = Sievert (Sv)

Adults:
Lifetime Attributable Risk of Cancer 1:1000 at 10mSv
Lifetime Attributable Risk of Cancer Mortality 1:2000 at 10mSv
 
Risk estimates follow a linear rate of change such that:
Lifetime Attributable Risk of Cancer in Adults = Radiation Dose (mSv) x 0.0001
Risk is Cumulative

Pediatrics:
Lifetime Attributable Risk of Cancer is greater than for adults and is age-dependent
Lifetime Attributable Risk of Cancer Mortality 1:1000 at 10mSv

Common Effective Dose Estimates (mSv)

Background radiation                     3.5/year (chronic exposure)
CXR                                             0.1
CT
    Head, Face                               2
    Neck, Cervical Spine                 2
    Chest, Thoracic Spine                8
    Abdomen                                7.5
    Pelvis                                     7.5
    Abdomen/Pelvis, Lumbar Spine 15
    Extremity                               0.5
 

Note that it doesn't take very much radiation to reach the 10 mSv level!

Bottom line: CT if you need to, but carefully consider whether it is worth it or not

One last pearl, carefully consider whether or not you want that d-dimer and don't order one unless you are prepared to order a CT scan.

Great case of bradycardia today in the ED-requiring transvenous pacemaker....cause?? K 7.6

Some bradycardia pearls:

• The dose of atropine is 0.5 mg IV. Can be repeated.
• Heart transplant patients will not respond to atropine as the transplant is denervated. Go right to pacing.
• Consider glucagon if suspected beta blocker toxicity....and be prepared...most patients vomit!
• DON"T FORGET THE K! A frequent cause of weird and insuspected bradycardia. I have had at least 3 cases of bradycardia (two requiring TV pacemaker insertion in the ED) due to hyperK in the last 3-4 weeks.
• Capture of the ventricle occurs when the complexes on the monitor become wide (assuming they weren't already wide)
• Search for the cause (MI, tox, metabolic, etc.)

With few exceptions, always assume that elderly patients presenting to the ED with an acute illness are very dehydrated. Here are a few reasons why the elderly patient, even on a normal day, may be mildly dehydrated:
1. The elderly have been shown to have decreased total body water.
2. The elderly have a decreased thirst response.
3. The elderly have a decreased renal vasopressin response.

Given these issues, when an elderly patient develops a systemic illness (especially pulmonary process), they lose even more fluid via insensible losses. By the time they arrive in the ED, unless they are presenting because of overt pulmonary edema, they almost always will benefit from generous IV fluid administration.

Amal

Diagnostic Errors in the Emergency Department

Believe it or not, there is actually a field of medicine that is devoted to examining how physicians think in clinical practice, i.e. how we make diagnostic decisions. Much of the work on this has been done by Pat Croskerry. This is extremely important for emergency physicians because we frequently have to make split second medical decisions with little to no information.

Why is this so important? If we can understand where errors are made, we can actually improve our own diagnostic skills and reduce our errors rates.

Some key pitfalls that we all fall victim to:

• Bias-this refers to the chart that says under past medical history "fibromyalgia, interstitial cystitis, bipolar, chronic constipation." This type of chart has set us up to potentially miss a diagnosis because our thought processes shut down before we have even started. Ever miss a diagnosis or almost make a mistake because of your feelings about a patient (sometimes BEFORE seeing them)? This is bias. Being aware of this dangerous pitfall in practice is the first step in preventing bias-related mistakes.
• Premature closure of the differential diagnosis-Now, we do this a lot in medicine. Some diagnosis falls in our lap (patient gives it to us, or a consultant tells us that is what it is) and we fail to r/o other things on our list. Key mistake we make is related to not considering other entities on the differential diagnosis. Take home point: Don't narrow the differential diagnosis until it is time to do so.

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Glucose-6-Phosphate Dehydrogenase Deficiency

• G6PD Deficiency is a genetic disorder which can cause hemolytic anemia when people with the disorder come into contact with drugs, food and other substances which cause oxidative stress.
• It is the most common genetic enzyme deficiency.
• G6PD is an inherited disorder with over 400 different known variants.
• Oxidative stress can cause the premature distruction of RBC's due to the lack of the enzyme reduced glutathione which G6PD helps produce.
• Drugs that are at high risk for causing hemolytic anemia in those with G6PD deficiency are:
  • NSAIDS (Asprin, Tylenol, Ibuprophen)
  • Quinolones
  • Sulfa drugs
  • Drugs metabolized known to cause blood or liver related problems or hemolysis
  • Primaquine
  • Nitrofurantoin
  • Glyburide
  • Dapsone

Also make sure that you are not G6PD deficiency if you are eating with Hannibal Lecter as Fava beans and other legumes can also cause an episode of hemolysis.

A good reference for G6PD deficiency is http://g6pddeficiency.org/index.php

Hyphema is an urgent ophthalmologic condition. Due to the high risk of rebleeding and increased intra-ocular pressure, strict follow up with an ophthalmologist is warranted. SELECTED low grade hyphemas in reliable patients may be managed on an outpatient basis. Some pointers that may be helpful for the EM inservice exam: 

• Measurement of intra-ocular pressure (IOP)  is crucial to proper treatment and prognosis.
• Many drugs are available to lower IOP, these are generally used in association with opthalmologic consultation
  ->acetazolamide (has potential to "sickle" RBC's)
  ->aminocaproic acid
  ->B blockers
• Hyphema > 5 days are associated with high incidence of synechiae formation
• Avoid NSAIDs/ ASA
• Eye patching,  HOB (head of bed) elevation recommended
• Corneal bloodstaining indicates a poor prognosis
• Incidence of rebleeding estimated at 30-40%
• Graded from 0-IV. Grade IV hyphemas cover the entire anteror chamber; often called, "8 ball" or "blackball" hyphema. Grade 0=only visible on slit lamp.
• Trauma is most common etiology
• Low IOP and trauma? ---> Rule out globe rupture! 

General indications for "very urgent" ophthalmologic consultation:

• Severely impaired visual acuity=greater rebleeding risk
• Patient with known SCD or sickle cell trait
• Visible blood staining of cornea
• High grade, covering > 1/3 of anterior chamber
• Delayed presentation (risk of synechiae / vision loss due to IOP) 

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Pitfalls in ED Teaching

One of the best ways to improve as a teacher is to understand what mistakes expert educators have made in the past.

The following is a short list of pitfalls offered from some of the great teachers in our specialty:

• Trying to teach for too long: "Teaching less is more"-that is to say, more will be remembered if the teaching session is brief.
• Trying to teach too much: Trying to Stick to one main point, the "Educational Hit and Run," and move on
• Failure to be enthusiastic when you teach: You must have some enthusiasm when you teach. Students/Residents won't learn as much or be as enthusiastic about learning without your enthusiasm!

Feedback as a Teaching Tool

Why do we, in general, stink at giving feedback?

• We were never taught how to do it
• We fear we will hurt someone's feelings
• It's painful to give feedback

Consider a few quick pearls that will increase your success at giving valuable feedback:

• Realize that learners (students/residents) crave feedback....proven in multiple studies
• Feedback IS a powerful teaching tool and isn't just a way of evaluating someone.
• Avoid at all cost, the phrase,"good job." Be specific about what you mean
• Praise in public, perfect in private
• Avoid the "complain syndrome" and don't fall victim to it. This refers to the phenomenon in which we complain about a behavior or trait and NEVER actuall tell the person. We have all done it. Set yourself apart from others by giving the learner the needed feedback.
• Learners won't improve without feedback. Just like the Nike commercial says,"Just do it!"

FrostBite

Now that we are in the cold winter months, we are more likely to see patient with frostbite and hypothermia.  Here are some tips for treating frostbite.

• Rapidly rewarm the affected body part.  Never attempt rewarming if there is risk of refreezing.
• An appropriate warming technique tub of water at 40-42°C. Higher temperatures should be avoided secondary to the risk of burns. If a tub is not available, use warm wet packs at the same temperature.
• It can take up to 40 minutes for the affected area to thaw.  Thawing is complete when the distal areas flush.
• The only indication for early surgical intervention is debridement of blisters, necrotic tissue or fasciotomy if there is  compartment syndrome.
• It often takes 1-3 months for frostbitten tissue to be declared viable. The affected area generally heals or shrivels and dries up without surgery. Amputation should be delayed as as long as possible. Early surgical consultation for amputation is rarely needed.

Adapted from Frostbite: Treatment and Medication by C. Crawfor Mechem, MD, MS, FACEP as posted on eMedicine.com.

BACKGROUND: 

For the first time since its publication, the centers for disease control has dedicated an entire issue of their Morbidity and Mortality Weekly Report to an emergency medical services topic. Vol 55 RR-1 reviews the, "Guidelines for Field Triage of Injured Patients." The report represents a consensus opinion of national experts in EMS, EM, and trauma care. It outlines which patients may be best served via transport to a trauma center.

CRITERION LINKED TO SEVERE INJURY  (Consider transport to nearest TRAUMA CENTER) 

• GCS < 14, SBP < 90 mm Hg, RR < 10 or > 29 per minute (or less than 20 for infants) 
• Penetrating wounds to neck, torso, head
• Flail chest, two or more proximal long bone fractures
• Proximal extremity amputation
• Paralysis
• Open or depressed skull fracture
• Older patients on anticoagulation

From the MMWR: "The National Study on the Costs and Outcomes of Trauma identified a 25% reduction in mortality for severely injured patients who received care at a Level I trauma facility." 

EXTRAS: 

The remainder of the report details the triage decision making process, explains trauma center capabilities, and provides an interesting and detailed review of trauma transport criteria. Link to the current issue is attached.

http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5801a1.htm

Teaching in the Emergency Department

Effective ways to teach in the ED:

• Limit the amount of time you spend teaching (more teaching does not = more learning)....Take Home Point: teach a quick pearl about a case and move on. Dont belabor the point and keep teaching for 5-10 minutes. You will loose the learner.
• Make teaching points applicable to the patient. Theoretical stuff is fine but no one cares about the Krebs cycle or ATP.
• Teach "on the fly" (teach as good teaching moments come up on each case). "Board talks" are nice but are often times not practical in a busy ED.
• Above all, be enthusiastic...without this all teaching will be ineffective

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The glucometer is one of the devices that we quickly reach for in the management of our unresponsive patients, diabetics and in the critically ill.  Recently, I noticed that our Roche Accu-Check has a big sticker on the case stating that results could be affected by therapies that alter the metabolism of galactose, maltose, and xylose.  Since this was a big hole in my fund of knowledge I decided to look up what else affects the accuracy of glucometers.

 Now, Dr. Winters already warned used about the inaccuracy of bedside glucometer readings in the critically ill, but what about the patient that is not septic and/or in shock.

Substances/Drugs that have been reported to affect the accuracy of glucometers are:

• Levodopa
• Dopamine
• Mannitol
• Acetaminophen
• Severe lipemia
• Severe unconguted bilirubin
• Elevated Uric Acid
• Maltose (present in immunoglobin products)
• Patient on peritoneal dialysis secondary to Icodextrin
• Ascorbic Acid (Vitamin C)

Anemia also results in higher values, and a capillary blood sample can differ from venous blood by as much as 70mg/dL.

Most errors are more significant when dealing with hypoglycemia. 

So the moral of the story is be careful with a bedside glucometer when the reading is low, as the venous blood sample sent to the lab may return even lower.  Error on the side of treating the patient with glucose.

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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

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.

Superior Vana Cava Synrome....when to suspect

Two common causes of SVC syndrome include thrombus (secondary to CV catheters) and lung tumors/lymphoma

Consider this diagnosis in patients with a history of cancer and/or who have a central line in place and the complaint of facial swelling. Patients may not look swollen to you.

In addition, make sure to look at their necks and chest wall-presence of asymmetric, prominent veins should prompt consideration for this diagnosis. 

A useful clinical tool is to look at the patient's driver's license (assuming they have one) and compare to their appearance on presentation.

Workup in most cases will involve a CT of the chest.

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Suspected Acute Leukemia in the ED

 Key ED Interventions for patients with astronomically high WBC counts:

• Usually talking about WBC counts over 200,000 or so (can be lower in lymphocytic leukemia)
• Hydrate aggressively
• Avoid PRBC transfusions as blood products will increase the patient's cytocrit (combination of WBC, platelets, and RBC) and predispose to organ malperfusion. This may lead to WBC (or blast) sludging in the microcirculation and may result in CNS bleeds. 
• Obviously, call for help immediately! Get a hematologist on the line quickly
• Assume the patient already has Tumor Lysis Syndrome and administer Allopurinol in a dose of 300 mg orally.
• Obtain a uric acid level, and if high, give an intravenous infusion of Rasburicase-eliminates preformed uric acid released from leukemia cell lysis. Renal failure results from high uric acid levels. We have this medication at University.
• The treatment of choice is initiation of definitive chemotherapy....clearly not an option for us in the ED. You can also do leukapheresis (where you take out WBC)....also not an option unless you have a special catheter and a perfusionist/nurse. BUT, you can take off a unit or two of blood (phlebotomy). This will potentially lower the patient's cytocrit. 

Neutropenic Fever

A few pearls about neutropenic fever:

• Usually occurs a few weeks after chemotherapy (14-21 days)
• Defined as a fever in the setting of rapidly declining neutrophil count
• Patients who report fever at home but who are not febrile in the ED should be treated as if they are neutropenic
• ANC=absolute neutrophil count. Calculated by adding neutrophils and bands together
• Classification of neutropenia, use the ANC to calculate:  Mild: 1000-1500 cells/mm³, Moderate 500-1000 cells/mm³, and Severe Less than 500 cells/mm³.
• Mortality rate increases as the ANC drops to below 500 and the duration of neutropenia. These people die of overhwhelming bacterial infections/sepsis.
• Treatment: #1 Consider the diagnosis, #2 Broad spectrum antibiotic coverage: Imipenem, or Pip/Tazo, or Cefipime. Consider adding Vanc if the patient has a line, looks ill or is hypotensive, or if the patient has been on a fluoroquinolone.

#1 Pitfall:

• Not initiating broad spectrum antibiotic coverage fast enough. These patients can crash very rapidly.
• Patients do not have to be febrile in the ED to be diagnosed with this. Their report of fever is enough.
• Mortality rates drop the faster big gun antibiotics are given. Don't be skimpy and give Unasyn. Use the big bad boys like single agent Pip/Tazo (4.5 grams, not 3.375), Cefipime, etc. Have a low threshold for adding Vancomycin.

IDSA Guidelines on Neutropenic Fever, 2002. New Guidelines coming Summer 2008!