With recent events, a few notes about ricin seems appropriate:
- Easy to make from castor bean though heat labile
- No antidote, though Fab like digibind is in development
- Granule size of the grain of sand can kill
- Inhalation, IM, IV all effective
- After immediate exposure likely no symptoms
- Vomiting and diarrhea initially, acute lung injury and death in 3-5 days
CDC website: http://www.bt.cdc.gov/agent/ricin/
General Information:
A parasitic infection caused by the tissue-dwelling filarial nematode worm Wuchereria bancrofti; a wide range of mosquitoes transmit the infection. When the worm is mature, it inhabits lymph nodes and produces sheathed microfilarial larvae that circulate in the peripheral blood.
Clinical Presentation:
- Infection with the adult worms produces painless subcutaneous nodules that are usually less than 2 cm in diameter, typically over bony prominences.
- Symptoms depend on where the microfilariae migrate to, and vary accordingly. They include: pruritus, papular dermatitis, dermal atrophy and depigmentation or hyperreactive skin disease (Sowda), keratitis, iritis, chorioretinitis, optic atrophy and eventually blindness, orchitis, hydrocele, chyluria, elephantiasis, pulmonary eosinophilia, cough, wheezing, and splenomegaly.
Diagnosis:
- Peripheral blood smear taken between 11pm and 1am or after provocation using diethylcarbamazine (DEC).
- Filarial antigen test.
- Eosinophilia, and specific antiflarial IgG and IgE antibodies.
Treatment:
- DEC which must be obtained directly from the CDC.
- Alternatively Doxycycline. Both drugs are effective against both macro and micro-filaria.
Bottom Line:
One billion people globally are at risk for infection with filaria. 120 million already have the infection. Suspect the infection in patients that have been to Africa, Asia, especially India, Western pacific, Haiti, the Dominican Republic, Guyana and Brazil.
University of Maryland Section of Global Emergency Health
Author: Walid Hammad, MD
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Massive Transfusion Pearls
- As discussed in previous pearls, massive transfusion (MT) is defined as the transfusion of at least 10 U of packed red blood cells (PRBCs) within 24 hours.
- While the optimal ratio of PRBCs, FFP, and platelets is not known, most use a 1:1:1 ratio.
- Though scoring systems have been published to identify patients who may benefit from MT (ABC, TASH, McLaughlin), they have not been shown to be superior to clinical judgment.
- A few pearls when implementing massive transfusion for the patient with traumatic shock:
- Monitor temperature and aggressively treat hypothermia.
- Monitor fibrinogen levels and replace with cryoprecipitate if needed.
- Monitor calcium and potassium. MT can induce hypocalcemia and hyperkalemia.
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Question
35 year-old female presents with fever and hypotension. Bedside ultrasound is performed and is shown here. What's the diagnosis?
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- Persistent junctional reciprocating tachycardia (PJRT) occurs in children and is characterized by an incessant & sometimes even permanent narrow complex tachycardia
- PJRT also occurs in adults but in about half these patients it is paroxysmal rather than incessant/permanent
- PJRT is a form of orthodromic AVRT and is caused by a concealed slowly conducting decremental accessory pathway
- Unlike accessory pathways of Wolff Parkinson White syndrome in children that are associated with a structural heart defect in about 1/3 of patients accessory pathways of PJRT are generally isolated
- PJRT can be a serious arrhythmia, particularly in children because of tachycardia-induced cardiomyopathy (TIC) - deterioration of ventricular contractile function caused by very prolonged periods in tachycardia
- LV dysfunction generally resolves following successful ablation of the tachycardia and is indicated even in the very young when the rate is not controlled and especially in patients with persistent left ventricular dysfunction.
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You have a patient with a spinal cord syndrome and you order the MRI. Have you ever had that conversation with radiology where you have to "choose" what part of the spine you want imaged?
The entire spine needs to be imaged!
The reason: False localizing sensory levels.
For example: The patient has a thoracic sensory level that is caused by a cervical lesion.
A study of 324 episodes of malignant spinal cord compression (MSCC) found that clinical signs were very unreliable indicators of the level of compression. Only 53 patients (16%) had a sensory level that was within 3 vertebral levels of the level of compression demonstrated on MRI.
Further, pain (both midline back pain and radicular pain) was also a poor predictor of the level of compression.
Finally, of the 187 patients who had plain radiographs at the level of compression at referral, 60 showed vertebral collapse suggesting cord compression, but only 39 of these predicted the correct level of compression (i.e. only 20% of all radiographs correctly identified the level of compression).
The authors note that frequently only the lumbar spine was XR at the time of clinical presentation (usually at the referring hospital), presumably due to false localizing signs and a low awareness on the part of clinicians that most MSCC occurs in the thoracic spine (68% in this series).
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Adrenal insufficiency (AI) can be a life-threating condition and is classified as primary (failure of the adrenal gland) or secondary (failure of hypothalamic- pituitary axis).
Common causes of primary adrenal insufficiency include autoimmune destruction, infectious causes (TB and CMV), or interactions with drugs (e.g., anti-fungals, Etomidate, etc.). Secondary causes are usually due to abrupt withdrawal of steroids after chronic use, although sepsis and diseases of the hypothalamus or pituitary (e.g., CVA) may occur.
Signs and symptoms include fatigue, weakness, skin pigmentation, dizziness, abdominal pain, and orthostatic hypotension; it should be suspected with any of the following: hyponatremia, hyperkalemia, hypoglycemia, hypercalcemia, low free-cortisol level, and hemodynamic instability despite resuscitation.
Treatment:
• Correct underlying the disorder
• Resuscitation and hemodynamic support
• Correct hypoglycemia and electrolyte abnormalities
• Treat with hydrocortisone, cortisone, prednisone, or dexamethasone +/- fludrocortisone (Note: dexamethasone is attractive choice in the ED because it will not interfere with ACTH stimulation test)
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General Information:
-As of April 5th, 14 confirmed cases of a new influenza A virus (H7N9) have occurred in China. Six of those have died.
-Presumed transmission via infected poultry in bird markets, and thus far no person-to-person transmission has occurred.
-Likely susceptible to oseltamavir or inhaled zanamivir
Area of the world affected:
-China
Relevance to the US physician:
- Suspect in patients with a respiratory illness and appropriate travel history.
- Refer to CDC within 24 hours if test positive for flu A but cannot be subtyped
- If H7N9 is suspected, patients should be under droplet and airborne precautions
Bottom Line:
No human-to-human transmission from H7N9 thus far, but the possibility exists. Any unsubtypeable influenza A patient should be placed on droplet and airborne precautions and oseltamavir or zanamivir started immediately.
University of Maryland Section of Global Emergency Health
Author: Andi Tenner, MD, MPH
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Methods: A large retrospective case series evaluated 121 children under 6 years old with hypoglycemia from a sulfonylurea ingestion.
Results:
- In addition to dextrose, patients who received octreotide had a median of zero hypoglycemic episodes after octreotide (compared to 2 before treatment, p < 0.0001).
- Median blood glucose concentrations after receiving octreotide were also higher (62 mg/dL vs 44, p < 0.001).
- Most required only 1 dose of octreotide with no reported adverse effects.
Authors' Conclusion: Octreotide administration decreases the number of hypoglycemic events and increases blood glucose concentrations in children with sulfonylurea ingestion.
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Question
64 year-old female presents with chest pain following an argument with her husband. Her echocardiogram (apical four-chamber view) and ECG are shown. Her initial troponin is 10. What's the diagnosis?
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- Takayasu arteritis (TA) is a granulomatous vasculitis that affects the aorta and its major branches
- Involvement of the aortic arch is associated w/CNS symptoms, claudication, absent peripheral pulses, and cardiac manifestations
- The EULAR/PReS consensus criteria for Dx of childhood TA requires characteristic angiographic abnormalities of the aorta plus 1 of the following:
- Absent peripheral pulses or claudication
- Blood pressure discrepancy in any limb
- Bruits
- Hypertension
- Elevated acute phase reactants
- Gold standard for Dx is angiography; however, CT and MR angiograms are less invasive and can detect inflammation & luminal diameter changes
- Tx is challenging, steroids may induce remission in up to 60%
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Recent advances in resuscitation science have enabled emergency physicians to identify factors associated with good neurologic and survival outcomes. Cases of persistent ventricular dysrhythmia (VF or VT) present a particular challenge to the critical care provider. The evidence base for interventions in shock refractory ventricular VF mainly consists of case reports and retrospective trials, but such interventions may be worth considering in these difficult resuscitation situations:
1. Double sequential defibrillation
-For shock-refractory VF, 2 sets of pads are placed (anterior/posterior and on the anterior chest wall). Shocks are delivered as "closely as possible."1,2
2. Sympathetic blockade in prolonged VF arrest
-"Eletrical storm," or incessant v-fib, can complicate some arrests in the setting of VF. An esmolol bolus and infusion may be associated with improved survival.3 Left stellate ganglion blockade has been identified as a potential treatment for medication resistant VF.4
3. Don't forget about magnesium!
-May terminate VF due to a prolonged QT interval
4. Invasive strategies
-Though resource intensive, there is limited experience with intra-arrest PCI and extracorporeal membrane oxygenation. Preestablished protocols are key to selecting patients who may benefit from intra-arrest PCI and/or ECMO. 5
5. Utilization of mechanical CPR devices
-Though mechanical CPR devices were not officially endorsed by the AHA/ECC 2010 guidelines, there's little question that mechanical compression devices address the complication of provider fatigue during ongoing resuscitation.
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A new recommendation in the 2013 Ischemic Stroke Guidelines provides guidance on what to do in patients taking new oral anticoagulants who are deemed eligible for IV fibrinolysis. Here is what the guidelines say:
- The most helpful lab tests are not widely available.
- A detailed history is important, but not always obtainable.
Until further data are available, a history consistent with recent use of new oral anticoagulants generally precludes use of IV tPA.
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Children frequently present with "pink eye" to the ED. When they do, parents often expect antibiotics. How many of these kids actually need them? Previous studies have shown approximately 54% of acute conjunctivitis was bacterial, but antibiotics were prescribed in 80-95% of cases.
A prospective study in a suburban children's hospital published in 2007, showed that 87% of the cases during the study period were bacterial. The most common type of bacteria was nontypeable H. influenza followed by S. pneumoniae.
Topical antibiotic treatment has been shown to improve remission rates by 6-10 days.
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- Although Keppra has been used more frequently in clinical practice, there is little evidence for its use in status epilepticus.
- It has a wide spectrum of action and few drug interactions.
- Initially, case series appeared to be highly successful in terminating seizures as an add-on agent.
- A review of 2 prospective studies found efficacies of 44% as an add- on agent, and 75% as a primary agent. The studies had markedly different populations.
- In a retrospective study, the treatment failure rates were 3X higher than that of intravenous valproic acid as an add-on agent in terminating status epilepticus.
- Therefore, although it is used frequently, the evidence for use is limited and inconclusive in terminating status epilepticus.
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Spring is in the air... and so is rotavirus.
Area of the world affected:
· Diarrheal illnesses were responsible for 1.6 million deaths for children under 5 globally in 2002.
· This number has improved over the years, in part due to oral rehydration salts (ORS) which were developed for cholera.
Relevance to the US physician:
http://www.cdc.gov/surveillance/nrevss/rotavirus/region.html#top
· ORS are also important for rotavirus treatment and uncomplicated gastroenteritis in children and adults.
· Commercially prepared solutions have different concentrations of ingredients, but all will work as better treatment and rehydration than common household products like sports drinks and juice.
Bottom line:
Consider ORS in patients with uncomplicated acute gastroenteritis.
University of Maryland Section of Global Emergency Health
Author: Jennifer Reifel Saltzberg, MD, MPH
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Hormonal Dysfunction in Neurologic Injury
- In the critically ill patient with neurologic injury (SAH, TBI), the initial treatment focus is to maintain adequate cerebral perfusion pressure, control intracranial pressure, and limit secondary injury.
- Once stabilized, however, it is important to consider endocrine dysfunction in the brain injured patient.
- Endocrine dysfunction is common in neurologic injury and may lead to increased morbidity and mortality. In fact, over half of SAH patients develop acute dysfunction of the HPA, resulting in low growth hormone, ACTH, and TSH.
- In addition to hormonal dysfunction, sodium abnormalities (i.e. hyponatremia) are present in up to 80% of critically ill SAH patients.
- Consider hormonal replacement therapy (or hypertonic saline in cases of severe hyponatremia) for patients with evidence of endocrine dysfunction. For some, this therapy can be life-saving.
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- Identifying ST-segment changes in patients with LVH is frequently associated with false-positive diagnoses of acute coronary syndrome
- This study analyzed the ACTIVATE-SF database, a registry of consecutive emergency department STEMI diagnoses from 2 medical centers (411 patients)
- In patients with anterior territory ST-elevation, using a ratio of ST segment to R-S–wave magnitude >25% as a diagnostic criteria for STEMI significantly improved specificity for an angiographic culprit lesion (true positive)
- Although this rule requires further study in a larger population it may augment current criteria for determining which patients with ECG LVH should undergo PCI
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Knee Pain Injuries are Radiographs needed?
Many people know that the folks in Ottawa have come up with a rule to determine whether radiographs are needed in patients complaining of knee pain. The Ottawa Knee rules that that radiographs are only required for knee injuries with any of the following:
• Age 55 years or older
• isolated tenderness of patella
• tenderness at head of fibula
• inability to flex to 90'
• inability to bear weight both immediately and in the emergency department (4 steps)
Well another group in Pittsburgh have their own set of rules that were recently shown to be more specific with equal sensitivity. The Pittsburgh decision rules state that radiographs are only needed if
- There is a history of fall or blunt trauma AND ( Patient is < 12 or > 50 years old OR Patient is unable to walk for weight bearing steps in the ED. )
So consider using the Pittsburgh or Ottawa Knee rules the next time you have a patient with knee pain to determine if those radiographs are really needed.
The full article can be found at http://www.ajemjournal.com/article/S0735-6757%2812%2900566-9/abstract