UMEM Educational Pearls

Category: Toxicology

Title: Methemoglobinemia

Keywords: pyridium, methemoglobinemia, methylene blue (PubMed Search)

Posted: 8/30/2007 by Fermin Barrueto, MD (Updated: 12/9/2019)
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- Classic Clinical Finding: Cyanosis out of proportion to clinical symptoms (look real blue but not SOB) - Causative Agents: Benzocaine (and other local anesthetics), dapsone, nitrites, phenazopyridine (Pyridium) - When do you treat: significant tissue hypoxia (MI, CVA, Dysrhythmias), and if MetHb >20% asymptomatic - Treatment: Methylene Blue 1-2 mg/kg (0.1 -0.2 mL/kg of 1% methylene blue) over minutes

Category: Neurology

Title: Cheyne Stokes Respirations

Keywords: Cheyne Stokes, stroke, increased intracranial pressure (PubMed Search)

Posted: 8/29/2007 by Aisha Liferidge, MD (Updated: 12/9/2019)
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Cheyne-Stokes (CS) respirations, also known as "periodic breathing," results from the inability of the respiratory center of the brain, the brain stem (i.e. pons and medulla oblongata), to rapidly compensate for changing serum partial pressure of oxygen and carbon dioxide. CS is characterized by respirations of gradually increasing and decreasing tidal volumes, with interspersed periods of apnea. Conditions associated with CS: - Increased ICP (i.e. space occupying brain lesions such as hemorrhage and tumors) - Congestive heart failure - Altitude sickness - Toxic-metabolic encephalopathy - Carbon monoxide poisoning - High-dose morphine administration CS was first described by physicians John Cheyne and William Stokes. Wikipedia Encyclopedia. The Diagnosis of Stupor and Coma by Plum and Posner.

Category: Critical Care

Title: A quick vasopressor review

Keywords: norepinephrine, dopamine, vasopressin, phenylephrine (PubMed Search)

Posted: 8/28/2007 by Mike Winters, MD (Updated: 12/9/2019)
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-Norepinephrine: has both alpha-1 and beta-1 activity; stronger alpha than beta receptor agonist; increases MAP primarily through increase in SVR; dose 2-20mcg/minute -Phenylephrine: all alpha-1 activity; increases MAP through increase in SVR; initial dose 100-180 mcg/minute and titrate 40-60 mcg/min; primarily a 3rd line vasopressor -Vasopressin: a non-adrenergic vasoconstricting agent; activates vasopressin receptors; dose 0.01-0.04 Units/min; currently used as a second-line agent in the setting of sepsis; should not be used as the sole vasopressor medication due to gut and cardiac ischemia -Dopamine: activates dopaminergic receptors; at doses of 10-20 mcg/kg/min it has both alpha-1 and beta-1 activity; increases MAP primarily through increases in CO; stronger chronotropic agent than norepinephrine - will worsen existing tachycardia -Epinephrine: has potent beta-1 activity with moderate alpha-1 and beta-2 activity; at lower doses increases MAP through increase in CO; at higher doses increases MAP by increase in SVR; primarily used in anaphylactic shock; dose 1-20 mcg/min

Category: Vascular

Title: Weird Causes of Thoracic Aortic Aneurysm

Keywords: Thoracic, Aortic Aneurysm (PubMed Search)

Posted: 8/27/2007 by Rob Rogers, MD (Updated: 12/9/2019)
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Well, I know you have been having trouble sleeping lately since you have been asking yourself, "What are some really weird causes of thoracic aortic aneurysms?" So, here is a short list: 1. Syphilis 2. Takayasu's arteritis 3. Behcet's disease 4. Psoriatic arthritis 5. Relapsing polychondritis Great pearl for an upcoming Visual Diagnosis Jeopardy....oh yeah, baby, it's coming to a wednesday conference near you!

Category: Cardiology

Title: GPIIB/IIIA inhibitors in NSTE-ACS

Keywords: GPIIB/IIIA inhibitors, acute coronary syndrome, antiplatelet medications (PubMed Search)

Posted: 8/26/2007 by Amal Mattu, MD (Updated: 12/9/2019)
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The 2007 ACC/AHA Guidelines for management of patients with unstable angina and non-STEMI were just released. They once again suggest the use of abciximab (Reopro) as the preferred glycoprotein receptor antagonist in patients that are going for PCI. If there is an anticipated delay to PCI, then eptifibatide (Integrilin) or tirofiban (Aggrastat) are preferred. The best evidence for these medications is in patients being managed invasively rather than just medically.

Category: Med-Legal

Title: Acute Coronary Syndrome Legal Pearls (Part 1)

Keywords: Legal, Acute Coronary Syndrome, (PubMed Search)

Posted: 8/26/2007 by Michael Bond, MD (Updated: 12/9/2019)
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Acute Coronary Syndrome (our number one area of liability) ===>Undiagnosed MI is the number one area of liability in emergency medicine, internal medicine, and family practice. ===>In emergency medicine, undiagnosed MI accounts for approximately 30% of all dollars lost in litigation. ===>MI patients mistakenly discharged have a 25% mortality rate, twice the rate of admitted patients. ===>Emergency physicians miss 2% of MIs. Office practitioners miss about 10% of MIs. ===>Failure-to-diagnose is the most common allegation in litigation following missed MIs. Misinterpretation of EKGs is the second most common allegation. ===>Poor documentation is the most common mistake in failure-to-diagnose cases (ie: failure to document why the physician decided the patient did not have ACS). Thanks to Larry Weiss, MD, JD Disclaimer: This information does not constitute legal advice, is general in nature, and because individual circumstances differ it should not be interpreted as legal advice. The speaker provides this information only for Continuing Medical Education purposes.

Category: Pediatrics

Title: Lead Poisoning

Keywords: Lead Poisoning, Toxicology, Plumbism, CaEDTA, BAL, DMSA, Lead Lines, Basophilic Stippling (PubMed Search)

Posted: 8/24/2007 by Sean Fox, MD (Updated: 12/9/2019)
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Lead Poisoning In Baltimore, 4.6% of kids screened had high lead levels in 2006 Plumbism presents often with vague and nonspecific symptoms; however, have high index of suspicion if: ==> Listlessness, clumsiness, or loss of developmental skills, ==> Recurrent or intermittent abdominal pain, vomiting, and constipation ==> Afebrile Convulsions ==> Resides in a house built before 1950 ==> Family history of elevated lead ==> History of Pica ==> Iron Deficiency Anemia ==> Evidence of neglect/abuse Lead Level will not come back in a timely fashion to help direct care, therefore, presumptive Chelation may be warranted. Evidence to Support Lead Posioning: ==> Micorcytic Anemia ==> Elevated Erythrocyte Protoporphyrin ==> Basophilic stippling of erythrocytes ==> Glycosuria, aminoaciduria (from development of Fanconi s Syndrome) ==> Radiopaque flecks on AXR ==> Lead Lines (dense metaphyseal bands on knee and wrist x-rays) Chelation with CaEDTA, BAL, or DMSA depending on level and symptoms.

Category: Toxicology

Title: Colchicine Toxicity - The Point of No Return

Keywords: Colchicine, toxicity, poisoning (PubMed Search)

Posted: 8/23/2007 by Fermin Barrueto, MD (Updated: 12/9/2019)
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- Few medications are uniformly lethal after a certain amount is ingested. - Colchicine is one of those medications, >0.8 mg/kg ingested=100%mortality regardless of treatment. - Many people prescribe it without knowing the adverse effect profile. - In fact, the prescribing instructions tell you to take the patient to toxicity (nausea and vomiting). - After an acute overdose this would be the sequence of events assuming surivival: Phase Signs & Symptoms i Nausea, vomiting, diarrhea, dehydration, leukocytosis (0-24hrs) II Sudden cardiac death (24-36hrs), pancytopenia, renal failure sepsis, ARDS, rhabdo (1-7d) III Alopecia, myopathy, neuropathy, myoneuropathy (>7d) - Colchicine prevents/destroys microtubule spindle formation and thus acts like a chemotherapeutic agent killing the cells that replicate most. - Think twice when prescribing this medication to someone, especially a patient at risk for suicide or medication noncompliance (where they think a little is good so more is better).

Category: Neurology

Title: Cushings Reflex and Triad

Keywords: increased intracranial pressure, cushings triad, cushings reflex, intracranial hemorrhage (PubMed Search)

Posted: 8/22/2007 by Aisha Liferidge, MD (Updated: 12/9/2019)
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Cushings reflex = a hypothalamic response to brain ischemia wherein the sympathetic nervous system is activated which causes increased peripheral vascular resistance with a subsequent increase in BP. The increased BP then activates the parasympathetic nervous system via carotid artery baroreceptors, resulting in vagal-induced bradycardia. The brain ischemia that leads to cushings reflex is usually due to the poor perfusion that results from increased ICP due to head bleeds or mass lesions. Cushings reflex leads to the clinical manifestation of Cushings triad. Cushings triad = hypertension, bradycardia, and irregular respirations (Cheyne-Stokes breathing). Some sources describe widened pulse pressure (increasing difference between systolic and diastolic BP) as the 3rd component of the triad, rather than irregular respirations. Cushings triad signals impending danger of brain herniation, and thus, the need for decompression. Consider administering mannitol, hyperventilation, and elevation of the head of bed as temporizing measures. Cushings triad was first described in 1902 by Harvey Williams Cushing, an American neurosurgeon. -Physiology, 2nd Edition, Saunders, 2002, page 150. -Ayling, J (2002). "Managing head injuries". Emergency Medical Services31 (8): 42.

Category: Critical Care

Title: Anaphylaxis - Epinephrine use

Keywords: anaphylaxis, epinephrine (PubMed Search)

Posted: 8/21/2007 by Mike Winters, MD (Updated: 12/9/2019)
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-Epinephrine is the drug of choice for anaphylaxis -Several studies indicate that epi is underutilized in ED patients with anaphylaxis -Indications for epinephrine include bronchospasm, laryngeal edema (hoarseness, stridor, difficulty swallowing), hypotension, rapidly progressive reaction, and severe gastrointestinal symptoms (due to bowel edema) -The dose of epinephrine is 0.3 to 0.5 mL of 1:1000 IM -Pearl: IM injection into the lateral thigh (vastus lateralis) has been shown to produce considerably faster time to maximum drug concentration than subq injection or IM injection into the deltoid

Category: Vascular

Title: Neurologic Manifestations of Aortic Dissection

Keywords: Aortic Dissection, Neurologic (PubMed Search)

Posted: 8/20/2007 by Rob Rogers, MD (Updated: 12/9/2019)
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A retrospective study by Gaul et al. of 102 patients with aortic dissection showed that 29% of patients presented with neurologic symptoms. Interestingly, almost 1/3 of these patients reported NO chest or back pain...i.e. painless aortic dissection with neurologic manifestations. Neurologic presentations discussed in the study include: stroke-like symptoms, syncope, ischemic neuropathy, somnolence, seizures, coma, and spinal ischemia. Pearl: Consider the possibility of aortic dissection in patients with neurologic symptoms especially if symptoms are unusual or combined with other findings. Gaul C, et al. Stroke 2007 From Emergency Medical Abstracts (July 2007)

Category: Cardiology

Title: ACS and cardiac risk factors

Keywords: acute coronary syndromes, cardiac risk factors (PubMed Search)

Posted: 8/19/2007 by Amal Mattu, MD (Updated: 12/9/2019)
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The presence of "classic" cardiac risk factors (i.e. risk factors identified in the Framingham studies) is most useful for predicting the long-term risk of developing CAD, but they have limited utility at ruling out acute coronary syndrome. A recent study (ref below) from the CRUSADE registry (multicenter registry including tens of thousands of patients with ACS), for example, demonstrated that 10.5% of patients with proven non-STE MI had NONE of the traditional cardiac risk factors. NEVER rule out ACS just because a patient has few or no cardiac risk factors. The decision to admit and risk stratify patients should always be based on your HPI (OLDCAAR). [Roe MT, Halabi AR, Mehta RH, et al. Documented traditional cardiovascular risk factors and mortality in non-ST-segment elevation myocardial infarction. Am Heart J 2007;153:507-514.]

Category: Gastrointestional

Title: Medical Management of Upper GI Bleeds

Keywords: Peptic Ulcer Disease, Omeprazole, Bleeding (PubMed Search)

Posted: 8/19/2007 by Michael Bond, MD (Updated: 12/9/2019)
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Medical Management of Upper GI bleeds. Peptic Ulcer Disease: Proton pump inhibitors are the main stay of therapy. Use is based on the observation that pH over 6 is required for platelet aggregation whereas pH below 5 results in clot lysis. High dose IV therapy should be reserved with those that have high risk stigmata of rebleeding as seen on endoscopy. Regular dose IV or PO omeprazole can be used in most patients. Variceal Bleeding: Consider octreatide (50 mcg bolus followed by 50 mcg/hr IV) and non-selective beta blocker therapy to reduce bleeding. Human recombinant activated factor VII has gotten a lot of press lately though it did not reduce the risk of death at either 5 or 42 days in patients with liver related GI bleeds.A Wong T. The management of upper gastrointestinal haemorrhage. [Review] [31 refs] [Journal Article. Review] Clinical Medicine. 6(5):460-4, 2006 Sep-Oct. Marti-Carvajal AJ. Salanti G. Marti-Carvajal PI. Human recombinant activated factor VII for upper gastrointestinal bleeding in patients with liver diseases. [Review] [45 refs] [Journal Article. Review] Cochrane Database of Systematic Reviews. (1):CD004887, 2007. Martins NB. Wassef W. Upper gastrointestinal bleeding. [Review] [87 refs] [Journal Article. Review] Current Opinion in Gastroenterology. 22(6):612-9, 2006 Nov.

Category: Pediatrics

Title: Neonatal Hypoglycemia

Keywords: Hypoglycemia, Neonate, Glucagon, Dextrose (PubMed Search)

Posted: 8/18/2007 by Sean Fox, MD (Updated: 12/9/2019)
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Pediatric Hypoglycemia Hypoglycemia = <45mg/dL in symptomatic neonate; = <35mg/dL in asymptomatic Symptoms = jitteriness, tachycardia, apnea, cyanosis, tachypnea, hypotonia, temperature instability, lethargy, irritability, or abnormal cry. (almost anything!) - So check the Sugar EARLY Fasting (often from gastroenteritis and dehydration) - the most common etiology of ketotic hypoglycemia in nondiabetic kids Glucagon has diagnostic and therapeutic role If it improves hypoglycemia, then glycogen stores are sufficient. Remember to draw extra tubes for future endocrine work-up PRIOR to giving dextrose! Rule of 50 For neonates: 5ml/kg of D10; For children: 2ml/kg of D25. - 5x10=50, 2x25=50 Claudius, I., C. Fluharty, and R. Boles, The emergency department approach to newborn and childhood metabolic crisis. Emerg Med Clin North Am, 2005. 23(3): p. 843-83.

Category: Toxicology

Title: Local Anesthetics

Keywords: lidocaine, allergic reaction, toxicity (PubMed Search)

Posted: 8/16/2007 by Fermin Barrueto, MD (Updated: 12/9/2019)
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- Allergic reactions are extremely rare to local anesthetics but may occur with the "Amides". - If they occur, it is more likely due to a preservative found in some multi-dose vials: methylparaben. - Either switch to a single dose vial without preservative or change to an "Ester" where there is no cross-reactivity Amides: Bupivacaine, Etidocaine, Lidocaine, Mepivacaine, Prilocaine, Ropivacaine Esters: Chloroprocaine, cocaine, procaine, tetracaine

Category: Neurology

Title: Coagulation Disorders Causing Ischemic Stroke

Keywords: coagulopathy, stroke (PubMed Search)

Posted: 8/15/2007 by Aisha Liferidge, MD (Updated: 12/9/2019)
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-polycythemia rubra vera -sickle cell disease -essential thrombocytosis - TTP - Heparin-induced thrombocytopenia -Antithrombin III deficiency - Protein C or S deficiency - Factors V, VII, XII, or XIII deficiency -heparin cofactor II deficiency - dysfibrinogenemias -antiphospholipid/anticardiolipin antibodies -nephrotic syndrome -malignancy -pregnancy -oral contraceptives -dehydration

Category: Critical Care

Title: Acalculous cholecystitis

Keywords: acalculous cholecystitis, HIDA, cholecystectomy (PubMed Search)

Posted: 8/14/2007 by Mike Winters, MD (Updated: 12/9/2019)
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-Think about acalculous cholecystitis in the critically ill patient with fever, abdominal pain, and elevation of LFTs and bilirubin -Pathophys thought to be due to SIRS, biliary stasis, and ischemia -Abdominal pain is not always in the right upper quadrant -Patients have a high rate of complications - gangrene or perforation (40% to 60%) -Diagnostic studies: ultrasound (sens. 70%), HIDA (sens. 80% to 90%), CT (sens. 90%) -Consult surgery early because treatment of choice is surgical cholecystectomy; some can be treated with percutaneous cholecystostomy but this is up to your consultant

Category: Vascular

Title: mesenteric ischemia

Keywords: mesenteric ischemia, elderly, geriatric, abdominal pain (PubMed Search)

Posted: 8/12/2007 by Amal Mattu, MD (Updated: 12/9/2019)
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Suspect acute mesenteric ischemia in any older patient with risk factors (atrial fibrillation) who presents with ACUTE onset abdominal pain with a paucity of physical findings. And, don't be fooled by "gut emptying" symptoms of vomiting and diarrhea. If you think grandma has acute onset gastroenteritis, think again. The only way to pick up this diagnosis more is to think about it more often. (sent on behalf of Dr. Rob Rogers)

Category: Cardiology

Title: amiodarone agony

Keywords: amiodarone, adverse effects, arrhythmias (PubMed Search)

Posted: 8/12/2007 by Amal Mattu, MD (Updated: 12/9/2019)
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Times when amiodarone should be avoided in wide complex tachycardias: 1. prolonged QT or torsade de pointes -- amiodarone prolongs QT and may induce torsade or cause torsade to become intractable 2. pregnancy -- amio is the only class D antiarrhythmic...use anything else, even electricity! 3. rapid Afib with WPW -- the only published literature says this causes hemodynamic deterioration 4. AIVR -- turns it into asystole...a clean kill! 5. pseudo-VTach caused by hyperK, TCAs, and similar meds -- these are actually not VT but just wide complex tachycardias (that look like VT) caused by poisoned sodium channels...amiodarone further blocks the sodium channels and can cause asystole 6. pulseless VT or VFib cardiac arrest -- you won't actually make the patient worse, but the ONLY evidence indicates that all amio does is increase survival to ICU without improved mental status and without increasing survival to discharge...so essentially you take up more ICU beds and increase costs

Category: Med-Legal

Title: ED Chart Documentation (Part 2)

Keywords: Documentation, Charting, Legal (PubMed Search)

Posted: 8/11/2007 by Michael Bond, MD (Updated: 12/9/2019)
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ED Chart Documentation (Part 2) ==> If writing an addendum after-the-fact, identify the note by date and time. ( late entry ). Otherwise, NEVER alter the chart after-the-fact. ==> Always address the patient s documented complaints. ==> Don t write incident report filed. ==> Be specific about times for follow-up. (eg:2 days, 1 week, next available) ==> Provide a warning about sedatives (eg: Don t drive ). ==> Whenever possible, document past tolerance of toxic drugs when prescribed (eg: NSAIDs). ==> Document a warning not to drive when treating patients for a seizure, or when refilling anti-epileptic drugs. Courtesy of Larry Weiss, MD, Jd Disclaimer:This information does not constitute legal advice, is general in nature, and because individual circumstances differ it should not be interpreted as legal advice. The speaker provides this information only for Continuing Medical Education purposes.