UMEM Educational Pearls

Rocuronium is fast becoming the agent of choice for RSI in the Emergency Department. Here is a head to head comparison of the two drugs to understand why:

	Rocuronium	Succinycholine
Dose	1-1.2mg/kg	1mg/kg
Onset	1-1.5min	1min
Duration	7-12min	30-40min
Histamine Release	No	Minimal Yes
CVS Effect	Tachycardia rare	Severe Brady rare
Other Adverse Effect	No fasciculations, No ICP effect, No Rhabdo	Fasciculations, increase ICP, rhabdo, movement of displaced Fxs

 

• Cavernous sinus thrombosis, one of the three dural sinus thrombosis syndromes, is extremely rare and results from infection often originating from the face, sinuses, dental cavity, ears, and mastoids.

• Cranial nerves III, IV, V1, V2, and VI course along the walls of the cavernous sinus such that extraocular motion abnormalities (palsy/paralysis) commonly manifest with cavernous sinus thrombosis.

• Headache (usually sharp, unilateral, and in the distribution of V1 and V2 branches) is typically the initial presenting symptom, followed by eom palsy, mydriasis, diplopia, periorbital edema, visual abnormalities, mental status deficit, and coma.

Sepsis in Pregnancy

• Sepsis in the setting of pregnancy is primarily the result of pelvic infections such as chorioamnionitis, endometritis, septic abortion, or urinary tract infection
• In these patients, aerobic gram-negative rods (E. coli, Enterococci, Beta-hemolytic strep) are the principal etiologic agents
• An empiric broad spectrum antibiotic regimen is ampicillin, gentamicin, and clindamycin (or metronidazole)

 

 

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BEWARE sudden onset thoracic back pain

Just reviewed a case last week of a person who presented with back pain (thoracic) as the sole manifestation of an aortic dissection. No chest pain, belly pain, etc. JUST severe, acute, thoracic back pain.

Keys to staying out of trouble:

• Any sudden onset pain should be explained. Musculoskeletal pain doesn't normally present like this. Look for risk factors like HTN. If a person with HTN (even if not that high in the ED) presents with acute, severe, thoracic back pain the diagnosis of dissection should at the very least be considered.
• The key to making the diagnosis begins with thinking about the diagnosis.
• At the very least, include aortic dissection in EVERY patient you see with back pain, especially if sudden onset. I am not talking about the 95%+ people who don't really have anything wrong with them and who stumble into urgent care asking (begging) for Percocet.
• Sudden onset back pain should also prompt consideration for a AAA
• Just like all else in Emergency Medicine, always ask yourself if a "worst case scenario" could be present?, and the list for acute back pain is pretty short: dissection, AAA, fracture (by history), cancer, infection. Most of these, however, do not present acutely.

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Although intubation, oxygenation, and ventilation have been downplayed in recent years in the early management of patients with cardiac arrest, late-term pregnant patients DO require early airway support. Paients in the later stages of pregnancy have increased oxygen consumption and therefore have much lower oxygen reserves than non-pregnant patients. As a result, they tend to have central circulation desaturation much sooner. Additionally, they are at higher risk for aspiration because of delayed gastric emptying and lower esophageal sphincter relaxation. "This need for rapid intubation is a key difference between the pregnant women in cardiac arrest and nonpregnant patients." [reference: Atta E, Gardner M. Cardiopulmonary resuscitation in pregnancy. Obstet Gynecol Clin N Am 2007;34:585-597.]

Ankle sprains are typically treated with a short period of immbolization and then functional exercises are prescribed to rehabilitate the ankle.  A study published in the Lancet this week might just change that.  Lamb et al looked at 584 people with severe ankle sprains (unable to weight bear 3 days out from injury) that were randomized to be treated with a 10 day below knee cast, Aircast, Bledshoe Shoe or Tubular Compression dressing (similar to Ace Wrap).  Those that were treated with the Cast and Aircast had quicker return to function and less disability at 3 months.  There was no increased risk of DVTs in the cast group.

A commentary in the same issue points out that severe ankle sprains are associated with:

• lower levels of physical activity levels
• recurrent ankle sprains are often reported for months and years after initial injury.
• About 30% of patients with an initial ankle sprain develop chronic ankle instability, or repetitive giving way of the ankle during functional activities.
• There is also emergent evidence to link severe and repetitive ankle sprains to increased risk of ankle osteoarthritis.

Based on this article I think it is prudent to treat all patients with severe Ankle Sprains with a prolonged period of forced immobilzation (Posterior Splint, Short Leg Cast or Aircast).  I would also recommend the Aircast be used to prevent recurrent sprains especially if the patient is involved in sports that require jumping (Basketball, Volleyball) where the risk of reinjury is higher.

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You have a 44 y/o female patient with an arterial line monitoring her blood pressure which is reading 302/156 mm Hg.  Her heart rate is 140 bpm.  Her history reveals she is taking a monoamine oxidase inhibitor (MAOI) and has inadvertantly ingested tyramine at her friend's cheese/wine party.   What do you do?

• Conditions producing hypertensive crisis from catecholamine surges (phenylephrine overdose, cocaine, tyramine interactions, pheochromocytoma) can be treated with phentolamine
• Phentolamine is a nonspecifc alpha blocking agent which produces peripheral vasodilation with a resultant fall in blood pressure in most patients.
• Other uses include extravasation of some vasopressors (e.g. norepineprhine)
• May see an increase in HR after administration (once alpha blockade is established, beta-blocker can be administered)
• Dose: 5-15 mg IV/IM
• Duration: 30-45 minutes

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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• Angioedema occurs in less than 1% of stroke cases treated with tPA.
• Particularly associated with ACE inhibitor and beta blocker (less so) use.
• Symptoms are usually mild affecting the lips, tongue, and oropharynx.
• Check the patient for such symptoms at 45, 60, and 75 minutes post tPA administration.
• When present, consider treating with some or all of the following agents: 
   

             -- Diphenhydramine (Benadryl) 50 mg IV
             -- Ranitidine (Zantac) 50 mg IV
             -- Methyprednisolone (Solumedrol) 50 - 100 mg IV
             -- Racemic Epinephrine
             -- Anesthesia consult re: airway management

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!

Ventilator Associated Pneumonia (VAP)

• VAP is the leading cause of death among hospital acquired infections
• VAP causes prolongation of mechanical ventilation, ICU/hospital length of stay, and adds about $40,000 to the patient's admission
• As we care for more and more intubated patients for longer and longer periods of time, it is crucial to know some simple preventative measures we can do in the ED to reduce morbidity and mortality
• In the absence of contraindications, elevate the head of the bed to 30-45 degrees for intubated patients
• This is a simple, no cost intervention that has been shown to decrease the incidence of VAP

Torsades de pointes and polymorphic ventricular tachycardia are two terms that are often used interchangeably. However, they are not the same!

Torsades is a type of PVT that is characterized by an undulating appearance of the QRS complexes which give the rhythm the appearance of QRS complexes twisting around a central axis. The defining feature of torsades, however, is the presence of a prolonged QTc on the ECG before or after the run of torsades.

Although either rhythm is usually amenable to cardioversion/defibrillation, post-cardioversion treatment is very different between the two. Torsades should be treated with magnesium, whereas PVT can be treated with lidocaine, amio, or procainamide. Beware that treatment of torsades with any of these sodium channel blockers can actually prolong the QTc further and induce intractable torsades.

Lidocaine with Epinephrine and it use on Fingers and Toes

It has been taught for a long time that Lidocaine with Epinephrine should not be used on fingers, toes, ears and nose [There has to be a kid's song in there somewhere] due to the risk of vasoconstricition/vasospasm and possible digitial infarcation.

The short story is that this practice is not supported by the literature, and there are now numerous publications that have shown that lidocaine with epinephrine is safe for use on the finger tips.  It turns out the the original case reports were submitted with procaine and epinephrine and not lidocaine with epinephrine.  Most of the cases of digital infarction where with straight procaine that is now thought to have been contaiminated or too acidic pH close to 1 when injected.

The effects of epinephrine last approximately 6 hours. This time is well within the accepted limit of ischemia for fingers that has been established in digitial replanation.

So why use Lidocaine with Epinephrine:

1. Provides a longer period of anesthesia
2. Decreases bleeding which:
   1. Improves visualization of tendons and underlying structures
   2. Makes repairs easier
   3. Decreases need for a torniquet

 

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Epstein-Barr virus (EBV)-associated infectious mononucleosis (IM) 

Most commonly presenting clinical findings: fever, fatigue, exudative pharyngitis, lymphadenopathy, and hepatosplenomegaly. 

Self-limited illness that lasts an average of 2 - 3 weeks. 

Treatment is primarily supportive.  Use of ampicillin, amoxicillin, or penicillin during the acute phase not indicated and may result in the development of a morbilliform rash, which studies have suggested may occur in more than 50% of the cases.  Antiviral therapy is not recommended. Splenic rupture occurs in about 1 - 2:1000 cases.  Therefore, avoidance of activities that increase the risk for injury is recommended until splenomegaly has resolved. 

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There have been multiple case reports of patients who have had coronary stents who have been on clopidogrel for > 1 year who have developed coronary thrombosis after clopidogrel cessation. There are also reports of patients who have developed DVTs likewise after clopidogrel cessation. In vivo studies in diabetics have demonstrated increased platelet and inflammatory markers after clopidogrel withdrawal. It appears that abrupt discontinuation of clopidogrel may lead to a thrombotic state in susceptible patients.

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• Always be sure to examine a patient's carotid arteries for bruits when concerned about stroke and/or TIA.  Bruits suggest the presence of stenosis.
• Dijk and colleagues found that patients with > 50% carotid artery stenosis are at high rsk for stroke and TIA.
• Bruits are best ascultated by using the bell of the stethoscope and asking the patient to briefly hold their breath while trying to hear the abnormality.
• The American Heart Association recommends that symptomatic stenosis of > 50% undergo carotid endarectomy (CEA) within 2 weeks.  If CEA is contraindicated, stenting should be pursued.  CEA for stenosis of 70% to 99% is typically recommended regardless of symptomatology.

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Sedation and Analgesia in Mechanical Ventilation

• Mechanically ventilated patients routinely experience pain and anxiety from the presence of an endotracheal tube, ventilator strategies, placement of invasive catheters, surgical procedures, and even nursing procedures such as suctioning and repositioning.
• Recent literature highlights that many of our vented patients received inadequate amounts of analgesia and anxiolysis
• When giving anxiolytics and analgesics, focus first on analgesics. 
• Patients given analgesics first, followed by anxiolytics, consistently achieve goals with less amounts of supplemental medications needed.

Pulmonary Embolism-Beware Two Important Atypical Presentations

Seems like we have had several atypical PE presentations recently so I thought it timely to quickly highlight some of the well-reported presentations of pulmonary embolism. Remember, although we won't and can't diagnose every case, these types of presentations should at the very least prompt us to consider the diagnosis.

Atypical PE Presentations:

• Syncope-occurs in as many as 15-20% of patients. Make sure PE is on the differential diagnosis of the syncopal patient, especially if there was any preceeding shortness of breath or chest pain.
• Abdominal pain-we just had a case of this last week. A young female 6 weeks into a course of OCPS developed RUQ pain that radiated to the left shoulder. She had NO shortness of breath. However, the RUQ pain was pleuritic. Remember the movement of the diaphragm as it is responsible for abdominal pain presentations of both PE and pneumonia. A d-dimer was obtained and returned 3000. A CT scan was then ordered which showed a large right lower PE. What's the moral of the story? Well, it isn't to rule out PE in patients with belly pain. The lesson here is that upper abdominal pain may reflect disease in the chest (lower lobe pneumona and PE) and vice versa. To make matters worse an ultrasound of the RUQ was ordered 1st which showed gallstones!

Elevated troponin levels can have been found to be prognostic of complications, morbidity, and mortality (in-hospital, short-term, and long-term) in many non-ACS conditions, such as sepsis, myocarditis, stroke (including subarachnoid hemorrhage), CHF, and pulmonary embolism.

Bradycardia in children is most often caused by hypoxemia but can also be caused by acidosis, elevated ICP, vagal stimulation, heart blocks or overdoses. 

First degree heart block in otherwise healthy children can be caused by infectious diseases, myocarditis, rheumatic fever, Lyme disease and congenital heart disease.

Third degree heart block can be congenital, caused by maternal connective tissue disorders such as Lupus, or may result from cardiac surgery.

Any infant presenting with a third degree heart block should have an investigation for neonatal lupus. 

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