Though an uncommon event, Drug-Induced Autoimmune thrombocytopenia occurs in a variety of drugs. Having recently diagnosed a patient that was receiving the "double-dose" bactrim for an MRSA abscess, it is worth mentioning the other drugs that have been reported to do it. Platelet count can go down to lethal levels and result in death due to the coagulopathy. Treatment is effective with platelets and no contraindication like in TTP.

Drugs that have been reported to do it:

abciximab, acetaminophen, amiodarone, amphotericin B

Carbamazepine, danazol, diclofenac, digoxin

Methyldopa, procainamide

Rifampin, trimethoprim-sulfamethoxazole, vancomycin

Acute Kidney Injury and Tumor Lysis Syndrome

• Tumor lysis syndrome (TLS) is characterized by hyperkalemia, hyperphosphatemia, hypocalcemia, and hyperuricemia.
• Acute kidney injury in TLS increases patient mortality and can be caused by an obstructive uropathy from calcium phosphate crystalluria or uric acid crystal precipitation.
• Fluid resuscitation remains the primary treatment for TLS.
• Urine alkalinization, however, is no longer recommended, as it can result in calcium phosphate crystal precipitation. 
• Recombinant urate oxidase rapidly decreases uric acid levels and should be given to patients at high-risk for TLS and those with pre-existing kidney disease and high uric acid levels.

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Question

77 year old male presents to the Emergency Department one week after a motor vehicle crash in which he suffered minor facial injuries. He is now concerned because his eye looks like this. Diagnosis? 

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LBBB is defined by 3 criteria QRS >125msec, V1- QS or rS, and R wave peak time 60ms with no q wave in leads I, V5, V6

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I am often asked whether physical activity has a positive or negative effect on the overall health of knee cartilage. The answer is unclear. Published data are conflicting.

What is known and generally agreed on:

1) Physical activity has been shown to facilitate cartilage development in children

2) Forced immobility (spinal cord injury) results in rapid cartilage loss

3) The medial knee compartment experiences significant mechanical loads during weight-bearing activity and is often the primary site of knee OA

A recent study attempted to answer whether 1) long-term (10yrs) participation in vigorous physical activity would benefit knee cartilage in healthy adults and 2) whether there were certain subgroups with asymptomatic preexisting structural knee changes which predict a harmful cartilage response to long-term physical activity.

Vigorous = activity generating sweating or SOB at least 20min 1/wk

Healthy older adults (mean age 57.8 yr) performing persistent vigorous physical activity had an increased risk (odds ratio 1.5) of worsening medial knee cartilage defects but not of a change in cartilage volume

In those w/ asymptomatic preexisting structural knee changes, there was worsening of cartilage defects (odds ratio 3.4) and a trend toward increased rate of loss of cartilage volume (again in the medial knee compartment)

Long-term effects of vigorous physical activity may depend on the preexisting health of the joint

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Intussusception is the telescoping or prolapse of one portion of the bowel into an immediately adjacent segment.

• age: 3 months to 6 years, most common among 3-12 months (although case reports exist in adults)
• after constipation, most common cause of abdominal pain in infants and pre-school aged children
• classic triad: colicky abdominal pain, vomiting, and red currant jelly stools
  • occurs in only 10% -20% of cases
• although colicky pain is the most common symptom, 15-20% experience no pain
• vomiting is often the earliest symptom, but may be absent in 30-40% cases
• most patients (75%) without grossly bloody stool, may be positive for occult blood
• plain abdominal radiographs may be normal in 30% of cases
• consider in differential for intants with altered mental status/ lethargy
  • TIPS AEIOU - one of the "I"s is for intussusception
• choice of radiographic evaluation is institution-dependent
  • ultrasound may be diagnostic but is not therapeutic
  • air or contrast enema can diagnose and treat
  • both are operator dependent

Transplant patients are the norm now in the ED. Their drug lists are immense and are usually on some form of immunosuppression to prevent rejection of the transplanted organ. Two common medications are cyclosporine and tacrolimus. They share many adverse effects like hepatotoxicity, nephrotoxicity and hypertension. Here is the mechanism of action and some unique adverse effects to these powerful immunosuppressants (there are many more so be wary):

1) Cyclosporine - suppresses T-cell activation and growth. Unique toxicity - painful neuropathy of the fingertips and toes, cortical blindness

2) Tacrolimus - simiar to cyclosporine but actually hampers T-cell communication/signal transduction. Unique toxicity - can also cause cortical blindness but is also known to cause diabetes/hyperglycemiad

Two recently presented abstracts at the 2012 Society of Critical Care Medicine conference suggest that the combination of vancomycin and piperacillin-tazobactam may lead to acute kidney injury (AKI) in the critically ill. There may also be evidence to suggest that piperacillin-tazobactam alone increases the risk of AKI.

Both abstracts retrospectively compared patients who received either vancomycin alone or the combination of vancomycin and piperacillin-tazobactam. In both studies, the rates of AKI were significantly lower in patients treated with vancomycin alone as compared to patients receiving both vancomycin and piperacillin-tazobactam.

Bottom line: Although the current evidence does not support a change in our clinical practice, more prospective studies exploring this topic are necessary.

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Question

79 year old male with headaches, ataxia, falls, and difficulty urinating. What's the diagnosis?

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For patients presenting to the ED with chest pain,  we've been taught that “classic” or “typical” presentations for ACS (chest pressure with radiation to the left neck/jaw/shoulder/arm, dyspnea, diaphoresis, nausea, vomiting, lightheadedness) are most worrisome. Yet, many of the patients that present with typical symptoms end up having negative workups for ACS. What are the symptoms that truly predict ACS? Three major studies have demonstrated that the best predictors of ACS in patients presenting to the ED with chest pain are (not necessarily ranked in order):
1. chest pain that radiates to the arms, especially if the pain radiates bilaterally or to the right arm
2. chest pain associated with diaphoresis
3. chest pain associated with vomiting
4. chest pain associated with exertion

The description of the chest pain (e.g. "pressure" or "squeezing," etc.), the dyspnea, nausea, lightheadedness, and pain at rest were, surprisingly, not helpful at predicting ACS.

The simple takehome point is the following: always ask your patient with chest pain if the pain radiates, if there was associated diaphoresis, if there was associated vomiting, and if the pain is associated with exertion. If the answers to any of these 4 questions is "yes," think twice before labeling the patient with a non-ACS diagnosis.

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Contrast Allergy:

Many patients will report that they have a allergy to iodinated contrast by saying that they are allergic to iodine

Iodine, itself, is not an allergen and is a required element for thyroid homrone production.  Plus could you imagine the hordes of people that would be having allergic reactions everyday when they add salt to their french fries.  Our EDs would be completely swamped.

A recent meta-analysis by Drs. Schabelman and Witting also showed the following:

• The risk of a reaction to contrast ranges from 0.2% to 17% depending on the type used, and the severity of the reaction considered.
• The risk of a reaction in patients with a seafood allergy is similar to that in patients with other food allergies or asthma.  Seafood is not unique to contrast media.
• A history of prior reaction to contrast increases the risk of mild reactions to as high as 7-17% but has not been shown to increase the rate of severe reactions.
• The risk of death due to contrast is estimated to be 0.0006 - 0.006%.

As we enter Crab eating season in Maryland, lets stop giving shellfish a bad name. A patent with any allergy is at increased risk, but shellfish is no higher a risk than those allergic to Strawberries.

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Definition: Fracture of the humerus just proximal to the epicondyles.

• Several macrolide antibiotics can cause QTc prolongation and dysrhythmias (e.g., erythromycin), but azithromycin is thought to have little cardiotoxicity.
• A cohort of patients taking azithromycin was compared to those taking no antibiotics, amoxicillin, ciprofloxacin, or levofloxacin.
• When compared to no antibiotics, amoxicillin, and ciprofloxacin, azithromycin was associated with a small but significant increased risk of cardiovascular death. Azithromycin was similar to levofloxacin.
• Important points:
  • Increased risk translates to 47 additional deaths per 1 million prescriptions.
  • Increased risk only occurs during the 5 day course and does not carry on after discontinuation.
  • Patients most likely to die were in the highest risk category based on preexisting cardiovascular diseases (245 deaths per 1 million prescriptions).
• Bottom line: Patients may start asking about this study finding when given a prescription for azithromycin. Although a small risk, it may be prudent to prescribe an alternative if patients have preexisting cardiovascular disease.

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Use the Measured Sodium Concentration!

• During a recent shift, a question arose regarding whether to use the measured or corrected sodium to calculate the anion gap in a critically ill patient with DKA.
• Recall that the anion gap provides an estimation of unmeasured anions - in this case acetoacetate and beta-hydroxybutyrate.
• Glucose is electrically neutral and therefore does not affect the anion gap.
• When calculating the anion gap in a patient with DKA, use the actual (measured) serum Na, rather than the corrected value.

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Question

19 year-old male presents with L ankle pain and obvious deformity after jumping out of a window and landing on his inverted foot. What's the diagnosis?

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New studies are utilizing mild therapeutic hypothermia as a treatment option in cardiogenic shock. These studies have reported improved circulatory support, an increase in systemic vascular resistance, and reduction in vasopressor use which ultimately may result in lower cardiac oxygen consumption. The preliminary results suggest that mild therapeutic hypothermia could be a therapeutic option in hemodynamically unstable patients independent of current recommendations which support its use in cardiac arrest survivors.

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• Wedge compression fractures

• Account for 50 – 70% of all thoracolumbar compression fractures
• Usually results from motor vehicle collisions and falls where an axial load is applied to the spine in flexion causing injury to the anterior column without posterior column injury
• Best seen on the lateral radiograph
• Simple wedge fractures are stable and have no associated neurologic injury
• Instability is present if
  • There is severe compression (>50%)
  • Kyphosis greater than 20 degrees
  • Multilevel compression fractures

http://jbjs.org/data/Journals/JBJS/855/JBJA0851224560G02.jpeg

It may not be necessary to give oral vitamin K to patients that are not bleeding that have INRs between 4.5 and 10.

Patients who were supratherapeutic on warfarin were randomized to vitamin K 1.25 mg (n=355) versus placebo (n=369).

In the 90 days after enrollment, 15.8% of patients allocated to vitamin K and 16.3% allocated to placebo had a bleeding event. Major bleeding events occurred in 9 patients in the vitamin K group and 4 in the placebo.

Thromboembolic events occurred in 1.1% of patients in the vitamin K group, compared to 0.8% of patients in the placebo group. An equal number of patients died in each group (n=7).

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Consider rhabdomyolyisis secondary to heat exposure as summertime approaches; have a low threshold to screen patients if they are at risk (e.g., people exercising in high-ambient temperatures).

Symptoms include muscle tenderness, cramping, and swelling with associated weakness. Patients with altered mental status (e.g., heat stroke) should be examined for limb induration, skin discoloration (i.e., ischemia), or compartment syndrome.

Complications:

• Electrolyte abnormalities (e.g., hyperkalemia and hypocalcemia) and malignant cardiac arrhythmias
• Metabolic acidosis
• Disseminated intravascular coagulation (release of tissue factor from muscle cells)
• Acute renal failure (myoglobin directly causes nephrotoxicity)

Treatment

• External cooling to cease the inciting process
• Aggressive fluid resuscitation with normal saline (avoid lactated ringers) for goal urine output of 200 to 300 ml/hour; foley catheters should be placed to monitor urine output.
• Start dialysis if potassium levels are elevated, acidosis, or oliguric renal failure. There is very limited evidence for the use of dialysis before the presence of these signs.
• There are no randomized controlled trials to support the use of mannitol (free radial scavenger and diuretic) or bicarbonate (to alkalinize the urine); their use is controversial.

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