This is a must memorize simple table of the toxic doses of local anesthetics. Toxicity of local anesthetics starts with slurred speech, lethargy to seizures and lethal cardiac dysrhythmias. There should be zero tolerance to actual cause toxicity when repairing a laceration or performing a fascia iliaca block.
Remember that a Bupivcaine solution 0.5% = 0.5 g/dL (%=g/dL) so a 70kg person, you can use a maximum of 2mg/kg x 70kg person. You can inject 140 mg in a 70kg person. This is a maximum volume injection of 28 mL if you were doing a fascia iliaca block. You can double the volume if you use a more dilute solution of 0.25%.
| Local Anesthetic | mg/kg |
| Bupivacaine | 2 |
| Ropivacaine | 3 |
| Lidocaine | 4 |
| Lidocaine with Epinephrine | 6 |
| Prilocaine | 6 |
Treatment for cardiac dysrhythmias due to local anesthetics is 20% lipid emulsion therapy - don't follow ACLS protocol as epinephrine or other antidysrhythmics (especially lidocaine) will be lethal.
General Information:
This year there have been over 280 cases of measles in the US, spanning 18 states; early recognition is key to preventing transmission.
Remember the 3 c's for recognition:
Cough, Coryza (runny nose), Conjunctivitis + febrile rash
-Incubation period is 10-12 days
-Symptoms usually start with fever, followed by rash 2-3 days later starting from the hairline and spreading to the trunk and extremities
-Completion of the first series of vaccines provides 90-95% immunity from measles
Relevance to the EM Physician:
-Immediately place any patient suspected of having measles on airborne precautions
-Look for koplik spots on the oral mucosa (commonly described as appearing like small grains of salt)
-Complications include diarrhea, otitis media, “measles croup,” pneumonia, encephalitis (1/1000 cases), and death (2-3/1000 cases)
-Post exposure prophylaxis (PEP) is recommended for unvaccinated exposed individuals and is effective up to 72 hours after exposure; however, vaccination is contraindicated in pregnant women
Bottom Line:
-The incidence of measles is rising sharply in the US. Vaccination, early detection, and post exposure prophylaxis for exposed individuals is key to reversing this trend.
University of Maryland Section of Global Emergency Health
Author: Bradford Schwartz, MD
Emergent reversal of Dabigatran
What is it:
Direct thrombin inhibitor used for stroke prevention in non-valvular atrial fibrillation
When do I worry about reversal:
Patients can have clinically important bleeding (GI hemorrhage, or Intracranial bleeding) or need reversal for emergent surgery
Patients with renal failure can have a prolonged medication effect
What can I do:
1. Activated charcoal: good for recent overdose or recent ingestion (within 2 hours)
2. Hemodialysis: around 60-65% can be removed within 2-4 hrs; putting in a dialysis line can be…bloody
3. FFP: in rat studies, has been shown to reduce the volume of intracranial hemorrhage. Unknown in humans. No good evidence of use based on coagulation mechanisms. Still worth a try though.
4. Recombinant activated factor VII: Has been shown to correct the bleeding time in animal studies. Probably the best bet in severe bleeding
5. Pro-thrombin complex concentrate: has been shown to decrease the bleeding time in animal studies
How do I monitor effect?
No great way here. Check aPTT and thrombin time (TT). At supra-therapeutic doses there is no good test.
Coming attractions: Dabigatran-fab for emergent reversal (see previous pearl: https://umem.org/educational_pearls/2415/)
30 year-old female with elbow pain following a fall. What's the diagnosis? (bonus points if you name the fracture with an associated radio-ulnar joint dislocation)
When examining a knee for a meniscal injury the commonly described tests are the McMurray Test and Apley Test. However, these tests have sensitivities of 48-68% and 41% respectfully, and specificities of 86-94% and 86-93% respectfully. Depending on whether you are looking at the medical or lateral meniscus.
The Thessaly Test that was first described in 2005 can be performed with knee in either 5 or 20 degrees of flexion and has a senstivity of 89-92% and specificity of 96-97% when performed in 20 degrees flexion. The test also tends to be easier to perform.
To perform the test:
Essentially you and your patient will look like you are doing the twist as they rotate their knee with you holding their hands.
A video of the technique can be found at http://youtu.be/R3oXDvagnic
Seizure is a very common effect seen in many overdoses. Think about the following drugs which have a higher propensity for seizure as noted in a Swiss study of over 15000 patients and isolating to single drug overdoses:
The most prevalent pharmaceuticals were mefenamic acid (51 of the 313 cases), citalopram (34), trimipramine (27), venlafaxine (23), tramadol (15), diphenhydramine (14), amitriptyline (12), carbamazepine (11), maprotiline (10), and quetiapine (10).
The drug mefenanamic acid is not used much in the USA but citalopram, venlafaxine and tramadol as well as the most prelavent bupropion which was number one in the study are all commonly prescribed in the USA. Keep a watchful eye if you see any of these drugs on a drug list or as an overdose.
General Information:
Bottom Line for the EM Physician: Use these guidelines to test stool only when helpful to patient care and avoid flushing resources down the toilet.
University of Maryland Section of Global Emergency Health
Author: Alex Skog
Are Intermediate Lactate Levels Concerning in Patients with Suspected Infection?
Diabetic patient with active intravenous drug use presents with hypotension, fever, and tenderness of right arm. What's the diagnosis and what antibiotic(s) would you start?
Happy Memorial Day! With all the recent attention in the news about swimming and drowning I thought I would share this article
The Instinctive Drowning Response—so named by Francesco A. Pia, Ph.D., is what people do to avoid actual or perceived suffocation in the water. And it does not look like most people expect. There is very little splashing, no waving, and no yelling or calls for help of any kind. To get an idea of just how quiet and undramatic from the surface drowning can be, consider this: It is the No. 2 cause of accidental death in children, ages 15 and under (just behind vehicle accidents)—of the approximately 750 children who will drown next year, about 375 of them will do so within 25 yards of a parent or other adult. In some of those drownings, the adult will actually watch the child do it, having no idea it is happening.* Drowning does not look like drowning—Dr. Pia, in an article in the Coast Guard’s On Scenemagazine, described the Instinctive Drowning Response like this:
This doesn’t mean that a person that is yelling for help and thrashing isn’t in real trouble—they are experiencing aquatic distress. Not always present before the Instinctive Drowning Response, aquatic distress doesn’t last long—but unlike true drowning, these victims can still assist in their own rescue. They can grab lifelines, throw rings, etc.
Look for these other signs of drowning when persons are in the water:
So if a crew member falls overboard and everything looks OK—don’t be too sure. Sometimes the most common indication that someone is drowning is that they don’t look like they’re drowning. They may just look like they are treading water and looking up at the deck. One way to be sure? Ask them, “Are you all right?” If they can answer at all—they probably are. If they return a blank stare, you may have less than 30 seconds to get to them. And parents—children playing in the water make noise. When they get quiet, you get to them and find out why.
Methylene blue is an extremely effective antidote for acquired methemoglobinemia but has important adverse effects if given in excess of recommended dose.
Below is the usual dose of methylene blue for treatment of methemoglobinemia
1-2 mg/kg of 1% solution IV with a repeat dose given if there is inadequate response to the first one
Adverse effects include:
General Information:
Area of the world affected:
Relevance to the US physician:
Bottom Line:
University of Maryland Section of Global Emergency Health
Author: Emilie J.B. Calvello, MD, MPH & Alex Skog
We've all heard Dr. Bryan Hayes warn us that, "Vanc & Zosyn is NOT the Answer for Everything" but things just got a little more serious, on a whole 'nother level...
Within the past few months, 2 cases of NDM-producing carbapenem-resistant pseudomonas have been reported in the area - one in Delaware and one in Pennsylvania. Previously, the only reported cases were found in Europe.
Few treatment options are currently available for carbapenem resistant organisms.
Appear to have retained some in vitro activity against these organisms, but are generally used as, "drugs of last resort".
Know it exists, take a good history, & know your local antibiogram. Prior to selecting a broad spectrum antimicrobial regimen, try to obtain previous antimicrobial culture data for patients with resistant organism infectious risk factors.
A patient presents with the rash shown below and is treated with penicillin. Fever, headache, and myalgia develop four hours later. What’s the diagnosis?
Lisfranc Fracture:
Typically consists of a fracture of the base of the second metatarsal and dislocation, though it can also be associated with fractures of a cuboid. Common current mechanism of injury is when a person steps into a hole and twists the foot. The original mechanism of injury that was described was when a horseman would fall of their horse with their foot still trapped in a stirrup.
Diagnosis should be considered if patient has difficultly weight bearing with pain on palpation over the 2nd and 3rd metacarpal head with an appropriate mechanism.
Pearls:
Mental health-related visits account for 1.6–6% of ED encounters. Patients with acute psychosis are often brought to the ED for clearance prior to psychiatric evaluation. Is this necessary?
Background: Several adult studies have shown that only 0–4% of patients with isolated psychiatric complaints have organic diagnoses requiring urgent treatment. Routine ED laboratory testing in adults is low yield still, with one study identifying abnormalities in only 2 of 352 patients—both mild hypokalemia. A pediatric study found that 207 of 209 patients were medically cleared.
This study was a retrospective review of pediatric psychiatric patients presenting to a an urban California hospital. They examined 798 patients who had an involuntary psychiatric hold placed by a psychiatric mobile response team.
The authors concluded that few pediatric patients brought to the ED on an involuntary hold required a medical screen and perhaps use of basic criteria in the prehospital setting to determine who required a medical screen (altered mental status, ingestion, hanging, traumatic injury, unrelated medical complaint, sexual assault) could have led to significant savings.
Currently, no effective reversal agent for new oral anticoagulants (e.g. direct thrombin inhibitor, dabigatran, and factor Xa inhibitors: rivaroxaban and apixaban) exists for emergent management of hemorrhagic complications.
Boehringer Ingelheim, the manufacturer of dabigatran, is developing an antibody fragment (Fab) against dabigatran as a reversal agent.1
A small ex-vivo porcine study demonstrated partial reversal of anticoagulation effects, measured by PT, aPTT, clotting time, clot formation time and maximum clot firmness, of dabigatran by PCC and activated PCC, while dabigatran-Fab achieved complete reversal. Recombinant fVIIa did not reverse the anticoagulation effect of dabigatran.2
Caution should be exercised when interpreting these finding as reversal of laboratory values does not necessarily correlate with clinical effect/outcome. However, dabigatran-Fab holds promise as an effective reversal agent of dabigatran.
Dabigatran-Fab is still under development and is not available/approved for clinical use.
Clinical Presentation
Rabies is, initially, a clinical diagnosis. To see what a patient with rabies looks like, check out this 3 minute YouTube video: (There is a bit of commentary by the person who posted it at the beginning that you might want to skip through.)
https://www.youtube.com/watch?v=EZbrNN9KeUI
Bottom Line
Rabies, while a rare disease in the US, can occur through either contact with infected animals (especially while traveling) or via organ transplantation. Recognizing the clinical syndrome is key to diagnosis.
University of Maryland Section for Global Emergency Health
Author: Andi Tenner, MD, MPH, FACEP
Prior literature has demonstrated the safety and feasibility of placing subclavian lines with ultrasound guidance; here's a link to a short educational video describing the technique.
The literature has been varied, however, as to which approach is best for venous cannulation with ultrasound; the supraclavicular (SC) or infraclavicular (IC) approach (see references below)
A recent study evaluated both approaches in healthy volunteers in order to determine which approach is superior for cannulation using ultrasound.
98 patients were prospective evaluated by Emergency Medicine physicians with training in ultrasound. In each patient, both SC and IC views were evaluated on both the left and right sides; each view was given a grade for ease of favorability (no patients were actually cannulated)
Overall, it was found that the SC view was significantly more favorable compared to the IC view; the right SC was non-significantly preferred compared to the left SC.
Risk Modifiers for Concussion and Prolonged Recovery
A history of prior concussion is a risk factor for future concussion (>2x risk).
For individual sports, boxing has the highest risk.
For team sports, football, ice hockey and rugby have the highest risk.
Women’s soccer confers the highest risk for female athletes.
Younger age confers increased risk.
Female sex confers higher risk when comparing similar sports with similar rules.
Those with migraine headaches may be at increased risk.
Risk of prolonged concussion
Most athletes have symptom resolution within one week
Post traumatic amnesia (both retrograde and anterograde) predict increased number and longer duration of symptoms.
Younger age also predicts pronged recovery.
Other studies have found associations with headache lasting greater than 60 hours, fatigue, “fogginess,” or greater than 3 symptoms at initial presentation. Cognitive studies have identified deficits in visual memory and process speed as predictors of prolonged recovery.
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