Modern Resident - The newsletter of AAEM/RSA
August/September 2013
Volume 5: Issue 2  |  FacebookTwitterLinkedIn


Your 2013-2014 Leaders:

President
Meaghan Mercer, DO

Vice President
Rachel Engle, DO

Secretary-Treasurer
S. Terez Malka, MD

Immediate Past President
Leana Wen, MD MSc

At-Large Board Members
Michael Gottlieb, MD
Calvin Hwang, MD
Sean Kivlehan, MD
Nicole Piela, MD
Edward Siegel, MD
Victoria Weston, MD

Medical Student Council President
Mary Calderone

Publications Advisor - Ex-Officio Board Member
Joel Schofer, MD RDMS FAAEM

Modern Resident Contributors

Copy Editor: Victoria Weston, MD
Managing Editor: Lauren Johnson, AAEM/RSA Staff

Special thanks to this issue's contributors:
David Carreon, MSIV; Thomas Doran, MSIV; Kaitlin Fries, MSIII; Michael Gottlieb, MD; Ashley Grigsby, MSIV; Casey Grover, MD; Nathan Haas, MSIV; Michael Hole, MSIV; Maite Huis in 't Veld, MD; Meaghan Mercer, DO; Alexandra Murray, MSIII; and Brett Rosen, MD.

Interested in writing?

Email submissions to: info@aaemrsa.org

Please submit articles by September 24th for the October/November edition.

Journal Club: Trauma and Transexamic Acid (TXA)
Meaghan Mercer, DO
University of Nevada Las Vegas
AAEM/RSA President

Transexamic Acid (TXA) is an antifibrinolytic that competitively inhibits the formation of plasmin, and without plasmin you cannot degrade fibrin clots. Maintaining blood clots in a bleeding trauma patient sounds like a good idea, right? The birth of the CRASH-2 Trial led to huge results on the "Effects of transexamic acid on death, vascular occlusive events, and blood transfusion in trauma patients with significant haemorrhage."1 This was an international randomized control trial that included 40 countries, 274 hospitals and >20,000 randomized patients. The primary outcome was death at four weeks and the secondary outcomes included: blood clots, surgery, how much blood patient needed and if they needed blood at all.

Initial Study Results: Four week mortality was 14.5% in TXA group vs. 16% in placebo group, incidence of clots was lower in the TXA group, likelihood and blood volume was equivalent in both groups, death from bleeding was 4.9% in TXA group vs. 5.7% in placebo group. Study Results Round Two — Subgroup Analysis when given within 1 hour — risk of death improved from 7.7% to 5.3% and when given >3 hours — much higher risk of death.2

All studies have caveats. We do not know the mortality benefit in traumatic brain injury patients, only 2% of patients who were included came from countries that have major investments in trauma systems and readily have access to blood products and early interventions. We do not know the exact mechanism of the drug because transfusion rates were not decreased in the TXA group, and fibrinolysis and coagulation testing were not included.

How to give TXA (dosage for major trauma): 1gm in 100mL in 0.9% NaCl over 10 minutes and then 1gm mixed in 500ml 0.9% NaCl over ~8 hrs (120 mg/hr or 60mL/hr). The contraindications are previous DVT or PE or prior hypersensitivity to transexamic acid. The potential adverse reactions include: allergic reactions, thrombotic events, hypotension (particularly with rapid injection), nausea, vomiting, diarrhea, impaired color vision and other visual disturbances.

With all of this data what does that mean to the practicing physician? TXA saves lives (when given under three hours) and is not associated with an increased risk in vascular occlusive events. The more severe the bleeding and hypotension, the greater mortality benefit the drug has. This is rapidly becoming a highly debated drug and should be one that you research and discover what side of the paradigm that you stand on. Some are so bold as to call it the "aspirin of trauma."3

References:

  1. The Crash-2 Collaborators. Effects of transexamic acid on death, vascular occlusive events, and blood transfusion in trauma patients with significant haemorrhage. BMJ. 2012;345:e5839.
  2. The Crash-2 Collaborators. Effects of transexamic acid on death, vascular occlusive events, and blood transfusion in trauma patients with significant haemorrhage. Lancet. 2011 Mar 26;377(9771):1096.
  3. Oden, D. http://www.christem.com/journ/2012/11/5/transexamic-acid-and-trauma.html.


Diagnostic Testing in Suspected Child Abuse
Brett Rosen, MD
York Hospital
Chair, AAEM Social Media Committee

Child abuse in pediatrics is one of the most unfortunate things emergency physicians have to manage in the evaluation of children. At some point in your career, you will likely be faced with the medical evaluation of a child who may be the victim of abuse. It is so common that subspecialists for this exist within both pediatrics and pediatric emergency medicine. However, you must report suspected child abuse to your state child welfare agency yourself. All but two states at the time of this writing mandate physicians to file a report of suspected child abuse, and the two that do not specify that physicians report actually mandate that every person who suspects abuse must make a report.

Determining the role of diagnostic imaging in children is a challenge. Weighed are the benefits of discovering injuries that may not be obvious versus subjecting the child to potentially harmful radiation and more pain than they already are experiencing with the discomfort of venipuncture. However, both of these are very important in evaluating these children from both a medical and legal aspect. A number of institutions around the country are fortunate to have specialized teams of nurses who are called upon to perform forensic examinations of these children, and are often willing to take transfers to their hospitals from other institutions of children needing this specialized care. However, this is not available in all institutions and explains why the emergency physician does need to understand the medicolegal aspects of evaluating these patients.

When evaluating a child with suspected abusive head trauma, the standard diagnostic test ordered is an unenhanced CT of the head. If you are also concerned about "shaken baby syndrome," consultation with pediatric ophthalmology for a fundoscopic exam to evaluate for retinal hemorrhages is also appropriate. The current American Academy of Pediatrics (AAP) recommendation is that all children under the age of 2 with suspected physical abuse must have a full skeletal survey. Between 2-5 years old, it is dependent on the clinical presentation and the reliability of the physical exam. Skeletal surveys have been shown to have little use in those above the age of 5. The use of a combined chest and abdomen X-ray, commonly referred to as the "Babygram," has absolutely no role in suspected abuse. The emergency physician should also make appropriate referrals to the pediatrician or child welfare center to ensure each child has a follow-up skeletal survey in two weeks, as a recent study showed over 20% (at least 1 in 5!) have new findings on repeat films.

Laboratory testing is also required in the vast majority of children you will see. Helping to guide us is a new recommendation from the AAP on evaluating children for bleeding disorders. There is now a distinction between isolated intracranial bleeds and bruising. For children with intracranial hemorrhages (ICH), evaluation for bleeding disorders may not be needed if there is independently witnessed trauma or other medical findings consistent with abuse. New recommendations state that if a bleeding disorder needs to be evaluated in ICH, test for a Factor VIII level, Factor IX level, PT/PTT, CBC with platelets and a DIC panel (d-dimer and fibrinogen) to be drawn.

A different set of testing is utilized for those who need evaluation due to unusual bruising. Again, the AAP recommendations state that a bleeding disorder evaluation may not be needed if there is "clear disclosure of or independently witnessed trauma or abuse," including pattern specific bruises, a clear history that explains the bruising or if there are other medical findings that are consistent with abuse. Petechiae at pressure sites, bruising in areas where objects press against the skin or extensive diffuse bruising should raise your suspicion and prompt this evaluation. In unusual bruising, the guidelines recommend testing for CBC with platelets, PT/PTT, Factor VIII level, Factor IX level, von Willebrand Factor Antigen and von Willebrand Factor Antibody (Ristocetin co-factor).

Aside from assessing for possible bleeding disorders, other testing may also be indicated based on your exam. A creatine kinase level is a good measure of muscle injury. You may want to order a hepatic function panel, amylase or lipase as a measure of possible intra-abdominal traumatic injury. Some advocate for calcium, phosphate and alkaline phosphotase to rule out intrinsic bone pathology. There is also some evidence which indicates that a urine toxicology screening should be performed in children who are being evaluated for neglect or nonaccidental burns and soft tissue injuries, as well as children with a history of either parental drug use or domestic violence. However, there is some debate as to the clinical implications of this testing. Further testing is dependent on your history and physical exam. Make sure you undress the child completely. The general rule is to do a thorough evaluation since you do not want to miss anything in these cases. Remember how important the job you are doing is for the safety and well-being of the child, both now and in the future.

References:

  1. AAP Section on Radiology. Diagnostic Imaging of Child Abuse. Pediatrics. May 2009. 123(5).
  2. Anderst JD, Carpenter SL, Abshire TC. Evaluation for Bleeding Disorders in Suspected Child Abuse. Pediatrics. April 2013. 131(4)
  3. Child Welfare Information Gateway. Mandatory Reporters of Abuse and Neglect. U.S. Department of Health & Human Services, Administration for Children & Families. August 2012.
  4. Harper NS, Eddleman S, Lindberg DM. The Utility of Follow-Up Skeletal Surveys in Child Abuse. Pediatrics. March 2013. 131(3).
  5. Oral R, Bayman L, Assad A, et al. Illicit drug exposure in patients evaluated for alleged child abuse and neglect. Pediatr Emerg Care. 2011 Jun;27(6):490-5.

Clinical Pearl: The Poor Man's CD4: The Absolute Lymphocyte Count
Maite Huis in 't Veld, MD
University of Maryland Medical Centre

In the United States an estimated 1 million people are living with human immunodeficiency virus (HIV) or acquired immune deficiency syndrome (AIDS).1 It is estimated that the prevalence of patients with previously diagnosed HIV in urban emergency department settings is as high as 3%.2 The CD4 count is frequently used as a predictor of the patient's susceptibility to infections and AIDS-defining illnesses. A CD4 count lower than 200 x 106 cells/μL is associated with an increased risk of opportunistic infections.3

In the emergency department setting, the CD4 count is not always readily available. Most patients do not recall their most recent CD4 measurement, medical records are not always available for review, and a CD4 count test takes hours to run and most laboratories do not have the resources to run the test immediately.2 This might pose a risk to the HIV patient presenting to the emergency department, as clinicians might underestimate the immune-compromised state of their patient. Overuse of resources like extensive testing and use of broad-spectrum antibiotics to cover both common and opportunistic microorganisms might also occur.

A readily available alternative to predict the CD4 count is the use of the absolute lymphocyte count.2,4 The absolute lymphocyte count can be calculated by multiplying the white blood cell count by the lymphocyte percentage. Several studies have suggested a relevant correlation between the absolute lymphocyte count and the CD4 count.2,4 An absolute lymphocyte count less than 950-1,000 cells/mm3 is predictive of a CD4 count smaller than 200 x 106 cells/μL with a sensitivity of 0.67-0.76, a specificity of 0.93-0.96, positive predictive value of 0.91 and a negative predictive value of 0.81. An absolute lymphocyte count greater or equal to 1,700-2,000 cells/mm3 is correlated with a CD4 count greater than 200 x 106 cells/μL with a sensitivity of 0.95-0.97, a specificity of 0.41-0.52, positive predictive value of 0.52 and a negative predictive value of 0.95.

The calculation of the absolute lymphocyte count and using the above mentioned cut-off points might help the emergency clinician in predicting the likelihood of opportunistic infections in the HIV patient presenting to the emergency department without a known recent CD4 count.

References:

  1. Rothman RE, Marco CA, Yang S. Aids and HIV Infection. Rosen's Emergency Medicine, 7th ed. Philadelphia, PA: Mosby Elsevier; 2010.
  2. Napoli AM, Fischer CM, Pines JM, Soe-lin H, Goyal M, Milzman D. Absolute lymphocyte count in the emergency department predicts a low CD4 count in admitted HIV-positive patients. Acad Emerg Med. 2011 Apr;18(4):385-9.
  3. Masur H, Ognibene FP, Yarchoan R, et al. CD4 counts as predictors of opportunistic pneumonias in human immunodeficiency virus (HIV) infections. Ann Intern Med. 1989;111:223-231.
  4. Shapiro N, Karras DJ, Leech SH, Heilpern KL. Absolute lymphocyte count as a predictor of CD4 count. Ann Emerg Med.1998; 32:323–8.

Image of the Month
Michael Gottlieb, MD
Cook County Emergency Medicine Residency

An 81-year-old man with PMHx of HTN, DM, HL and OA s/p right hip replacement presents to the ED with acute onset CP and SOB x 1 day. While watching TV earlier, he developed a sudden inability to catch his breath, as well as some poorly localized, pleuritic chest tightness on the right side of his chest. He initially attributed this to reflux, but when it did not improve he drove himself to the ED.

His initial vitals are: Temp: 98.2, HR: 56, BP: 132/78, RR: 28, O2 Sat: 89%. Upon examination, he is in moderate distress, appreciably tachypneic and has to stop halfway through his sentences to catch his breath. The remainder of his exam is significant only 2+ pitting edema bilaterally. Labs are pending, a chest X-ray is ordered and his ECG is shown below.

Which of the following is indicated in this patient?

  1. Antibiotics
  2. Pacemaker
  3. Furosemide
  4. Pantoprazole and a GI Cocktail
  5. Aspirin, Nitroglycerin and Morphine

Answer:
B is correct. This gentleman presented with a classic story for pulmonary embolus (which was later confirmed via CTPA). However, he is also significantly bradycardic (his ECG rate was 45 bpm), especially in light of his pulmonary embolus. Further examination of his ECG demonstrated complete dissociation of the atrial and ventricular beats (note the regularly spaced P to P intervals highlighted by red arrows in the picture below). Additional findings on this ECG include a right bundle branch block (QRS >120 msec, RSR in lead V1, and wide S wave in leads V5/V6) and a left anterior fascicular block (left axis deviation, small Q wave in lead I, large S wave in lead III, and an associated RBBB).

Third degree AV block (also known as complete heart block) is a medical condition in which the atrial impulse is unable to traverse AV node, forcing the ventricles to create their own rhythm, known as an “escape beat.” There are a variety of causes with the three most common being myocardial infarction, congenital lupus and Lyme disease. Patients may be discovered on an incidental ECG (as in this patient) or as a result of symptomatic bradycardia or hypotension. Because of the risk of severe bradycardia and dysrhythmias, most patients eventually require pacing. Mobitz Type 2 AV block is also an indication for pacemaker placement given its propensity to progress into complete AV block.

This case highlights the importance of always examining any additional tests or labs ordered, as it is easy to overlook other important findings after the initial diagnosis is made.

References:

  1. Rosen KM, Dhingra RC, Loeb HS, et al. Chronic heart block in adults. Clinical and electrophysiological observations. Arch Intern Med. May 1973;131(5):663-72.
  2. Epstein AE, Dimarco JP, Ellenbogen KA, et al. ACC/AHA/HRS 2008 guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities: executive summary. Heart Rhythm. Jun 2008;5(6):934-55.
  3. Kojic EM, Hardarson T, Sigfusson N, et al. The prevalence and prognosis of third-degree atrioventricular conduction block: the Reykjavik study. J Intern Med. Jul 1999;246(1):81-6.


Managing Bleeding Complications Due to New Direct Thrombin and Factor Xa Inhibitors
Thomas Doran, MSIV
Lake Erie College of Osteopathic Medicine

Eighty-five-year-old female presents via ambulance with an hour of epistaxis. Vital signs at triage are: Temp: 36.4°C, HR: 100 bpm, RR: 22 rpm, BP: 106/ 70 and SpO2 97% on 2L O2 via non-rebreather. On first impression she appears in moderate distress with obvious pallor. EMS has placed anterior nasal packing now saturated with gross red blood bilaterally. She has IV access and fluids are wide open. Her entire face and torso are a sanguine hue. Her daughter offers a medical history significant for atrial fibrillation. The med list available includes Rivaroxaban. Inspection of the posterior-oropharynx reveals a pulsatile stream of bright red blood. As you begin to gather your tools to address a sphenopalantine hemorrhage, the patient’s nurse breathlessly informs you that SBP has fallen to 86mmHg, HR is 120 and RR is 28. Type and cross are quickly added and as you race to her room to place a foley balloon and Rhino Rocket, you consider your options.

With major bleeding, long-established protocols drive clinician response when warfarin requires reversal. However, use of new oral anticoagulants (OAC) such as the direct thrombin inhibitor dabigatran and Factor Xa inhibitors rivaroxaban and apixaban is increasing and cases of clinically significant bleeding will be encountered more frequently.1 Recent literature offers guidance in our approach to these patients.

Are there antidotes for any of the new oral anticoagulants?
There are no proven antidotes for the new oral anticoagulants.1

Which coagulation studies will help me know the degree of anticoagulation?
INR is inappropriate for any of the new anticoagulants.1,2,3 For dabigatran, ECT (ecarin clotting time) is best but may not be available in your facility. Alternatively, aPTT can be informative. For rivaroxaban, PT correlates well but varies widely by institution and may be unreliable.1 An anti-factor Xa assay available for heparin and LMWH may be a better choice.4

What about overdose, intentional or otherwise?
Charcoal: In vitro studies simulating gastric pH have shown that >99.9% of dabigatran was adsorbed by activated charcoal. If the previous dose was ingested <2 hours prior to presentation charcoal is an option.5

Dialysis: Emergent dialysis is an option for dabigatran, but FXa inhibitors are largely protein bound and will not be eliminated with dialysis.4

I’ve heard that PCCs (prothrombin complex concentrates) are now recommended over FFP in warfarin reversal.5 Do they have a role here?
PCCs have been shown to reverse rivoraxaban’s PT prolongation but there have been no studies of the effect of PCCs on bleeding time in humans. Also, there is a significant risk of thrombosis associated with their use.5 However, in dire situations it may be reasonable to consider administration of PCCs in consult with hematology. Recombinant fVIIa can also be considered.5

Does FFP have a role?
Opinions vary but FFP is not likely to be helpful in emergent reversal of new OACs.1,5,6 Rather than replace depleted factors (as with warfarin reversal) altering the anticoagulation effects of the new OACs requires enough FFP to overcome their action. The volume of FFP required to do this is likely to be poorly tolerated in the ED patient.5

What’s the bottom line?
Gauge your response to the severity of the hemorrhage.

Mild: Stop the drug.6

Moderate: Stop the drug. Provide symptomatic tx, compression hemostasis, PRBCs/fluids, and standard hemodynamic support. Consider surgery, dialysis (dabigatran only) and/or charcoal.1,4,6

Severe or life-threatening: All of the above, plus consider administration of PCCs or rfVIIa, and/or FFP. Consult hematologist.5, 6

References:

  1. Pollack CV. Managing Bleeding in Anticoagulated Patients in the Emergency Care Setting. J Emergency Medicine. June 7, 2013.
  2. XARELTO (rivaroxaban) tablet, film coated, Dailymed.nlm.nih.gov, Permalink: http://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=0db92f9-2300-4a80-836b-673eae960
  3. ELIQUIS (apixaban) tablet, film coat, Dailymed.nlm.nih.gov, Permalink: http://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=e948622-7cc6-48a-acb6-c5450daae9b0
  4. Fawole A. Practical management of bleeding due to the anticoagulants dabigatran, rivaroxaban, and apixaban. Cleve Clin J Med. 2013 Jul;80(7):443-5.
  5. Kaatz S. Guidance on the emergent reversal of oral thrombin and factor Xa inhibitors. Am J Hematology. 87:S4-S45, 2012.
  6. Hatfield L, Chen S. UNC Healthcare ED Anticoagulation Reversal Guidelines. February 2013. Permalink: http://professionalsblog.clotconnect.org/wp-content/uploads/2013/03/UNCH-ED-Anticoagulation-Reversal-Guideline-02-18-2013-version.pdf.

Tox Talks: But the Urine's Negative?!
Recognition and Management of Urine Tox Screen Negative Drug Intoxications, Part 3
Ashley Grigsby, MSIV
Arizona College of Osteopathic Medicine

In Parts 1 & 2 of this article, many drug intoxications that are negative on the five panel drug screen were discussed. Due to the illusiveness of many drugs on our common drug screen, it is important to recognize their different toxidromes to better manage and treat these patients. In this final Part 3, common hallucinogens will be discussed.

Case: Seventeen-year-old male is brought in by his mother. Mom reports that child is acting strange. Child keeps talking about seeing sounds and hearing the color blue. Exam is normal except for mildly elevated blood pressure.

Hallucinogens
Hallucinogens have been used for hundreds of years, often for ritualistic reasons. Today, 1 million Americans use hallucinogens every year, mostly adolescents.1 LSD remains the prototype for hallucinogens, but many more have surfaced including salvia, magic mushrooms and blue mystic, along with many others. Dextromethorphan was discussed in Part 2, and PCP will give you a positive urine tox screen, therefore will not be discussed here.

Signs and symptoms:
Synesthesia (blending of senses, “hearing colors”) is common with hallucinogens. Users may feel like they are outside of their own body as an observer. Users may have elevated fear or panic attacks. Hypertension or tachycardia may be present, but usually do not require treatment.1

Life threatening effects:
Serotonin syndrome (triad of neuromuscular abnormalities, autonomic instability and altered mental status); hyperthermia indicates severe intoxication and requires aggressive management.1

Specific hallucinogens:

  • Blue Mystic – similar effects as LSD, but deaths have been reported1
  • Salvia – illegal in most states, except California, Maine and Maryland
  • Magic Mushrooms – more gastrointestinal effects: nausea, vomiting and diarrhea1

Treatment1:

  • Supportive care is usually sufficient
  • Place in calm, quiet environment (if you can find one in your ED)
  • Perform serial vital signs
  • Benzodiazepines for agitation
  • Haloperidol for psychiatric symptoms
  • Active cooling for hyperthermia
  • If serotonin syndrome occurs, sedation with benzodiazepines and possible cyproheptadine in severe cases may be required2

References:

  1. Delgado, J. Intoxication from LSD and other common hallucinogens. Up to Date. [Internet] 2013. [cited 2013 July 18]. <http://www.uptodate.com.millennium.midwestern.edu/contents/
    intoxication-from-lsd-and-other-common-hallucinogens?
    detectedLanguage=en&source=search_result&search=
    hallucinogens&selectedTitle=1~22&provider=noProvider#H8>
  2. Boyer, EW. Serotonin Syndrome. Up to Date [Internet] 2013. [cited 2013 July 18]. http://0-www.uptodate.com.millennium.midwestern.edu/contents/serotonin-syndrome?source=see_link

Bite Me: Animal Bites in the ED
Alexandra Murray, MSIII
Ohio University College of Osteopathic Medicine

Overview
Of all emergency department visits in the United States, approximately 1% are attributed to animal bites with up to 4.5 million people treated per year.1,2 While the true number of animal bites that occur is difficult to determine due to underreporting, the CDC reports that one in five of those who are bitten require medical attention.3 Of animal bites reported, approximately 60-90% are from dogs, 5-15% from cats and the remaining primarily occur from rodents, farm animals, monkeys, reptiles and arthropods.1-6 In addition, data from the 2009 Nationwide Emergency Department Sample showed that bites and stings from nonvenomous arthropods (such as ticks and mosquitoes), accounted for one-third of all animal-related treat-and-release ED visits and one-fifth of all animal-related inpatient discharges.4

Concerns and Treatment of Specific Bites
Dogs – Due to the blunt teeth and powerful jaws of dogs, almost every dog bite has a crush injury component to it. A dog can generate up to 450 psi of pressure which may result in damage to tissue well beneath the surface of the injury. These injuries may require debridement to remove any crushed tissue.1-5 Up to 18% of dog bites become infected and there is a broad spectrum of causative organisms. Studies show that most infections are caused by a combination of anaerobes and aerobes with 50% of bites containing Pasteurella species.5

Cats – Puncture wounds are the most common injury inflicted by cats due to their long, slim incisors that can penetrate deep into the skin. While cat bites may appear benign on the surface, the depth of the wound can extend to joints, tendons and even bone.1,2,5 These wounds can be difficult to debride and disinfect which is why 28-80% of cat bites become infected. Pasteurella species have been found in up to 57% of cat bites and there is frequently a mixture of aerobes and anaerobes present in the wound.4,6 It is important to monitor and rapidly treat the patient for Pasteurella sepsis as well as watch for Cat Scratch Fever (Bartonella henselae) and tenosynovitis.2,4-6

Wild animals – Wildlife has accounted for over 80% of reported rabid animals in the United States since 1975; however, over the last century we have seen a dramatic decline in the number of human rabies infections with only two to three cases reported per year.7 Information on rabies treatment consideration can be found on the CDC website (http://www.cdc.gov/rabies/medical_care/vaccine.html). Other zoonotic infections that can be spread from wild animal bites include tetanus, tularemia, leptospirosis, rat-bite fever and hantavirus.6-8 Rodent bites have an infection rate of approximately 10%, but are considered relatively low risk for contracting rabies.2,5-7

Spiders – Spider bites are very common but often cause only minor irritation. Of the 20,000 known species of spiders that inhabit the United States, only 60 are capable of biting humans. Of those 60, only four species (brown recluse, black widow, hobo spider, yellow sac spider) have been known to be dangerous to humans. The brown recluse and black widow are most dangerous and it is always important to consider a spider bite in the differential diagnosis of unexplained autonomic and neurological dysfunction.9,10

Treatment
Antibiotic treatment may be warranted depending on the severity of the injury. A broad spectrum antibiotic such as amoxicillin-clavulanate is recommended for most dog and cat bites.1,2,5 Determine if the patient is vaccinated against tetanus and administer either a primary series or a tetanus booster if none has been given in the past year. Assess the need for rabies vaccine and immunoglobulin.2,5,7 Spider bites can generally be treated with wound management and/or debridement. Occasionally, black widow bites may require antivenom.5,9

References:

  1. Benson LS, et al. Dog and Cat Bites to the Hand: Treatment and Cost Assessment. J Hand Surg. 2006; 31A: 468-473.
  2. Oehler R, et al. Bite Related and Septic Syndromes Caused by Cats and Dogs. Lancet Infect Dis. 2009; 9: 439-47.
  3. CDC. Nonfatal Dog Bite - Related Injuries Treated in Hospital Emergency Departments - United States, 2001. MMWR. 2003; 52(26): 605-610.
  4. Adams, A. (SSS), Sutton, J. (SSS), Elixhauser, A (AHRQ). Emergency Department Visits and Hospitalizations Associated with Animal Injuries, 2009. HCUP Statistical Brief #134. May 2012. Agency for Healthcare Research and Quality, Rockville, MD. http://www?.hcup-us.ahrq?.gov/reports/statbriefs/sb134.pdf
  5. Dendle C, Looke D. Review Article: Animal Bites: An Update for Management with a Focus on Infections. Emergency Medicine Australasia. 2008; 20(6): 458-67.
  6. Boillat N, et al. Animal bites and infection. Rev Med Suisse. 2008; 4(174): 2149-52, 2154-5.
  7. Blanton JD, et al. Rabies surveillance in the United States during 2011. J Am Vet Med Assoc. 2012; 241(6): 712-22.
  8. Hartmann K, et al. Leptospira Species Infection in Cats: ABCD guidelines on prevention and management. J Feline Med Surg. 2013; 15(7): 576-81.
  9. Braitberg G, Segal L. Spider Bites - Assessment and Management. Aust Fam Physician. 2009; 38(11): 862-7.
  10. CDC - Venomous Spiders. February 24, 2012. Available at: http://www.cdc.gov/niosh/topics/spiders/. Accessed July 4, 2013.

Top Apps for Medical Students
Kaitlin Fries, MSIII
Ohio University College of Osteopathic Medicine

As the end of the summer approaches, thousands of medical students are heading out to the wards to begin rotations. This is an exciting time because for many of us this marks the end of our classroom careers. It is now time to dive in and absorb as much knowledge as possible. Many of us will be nervous and might even consider stuffing our white coat pockets with every pocket size manual sold. However, thanks to today’s technology there are tons of quality professional apps available to us at little to no cost. So which apps should you download? Recently, University of Pennsylvania Perelman School of Medicine and Harvard Medical School surveyed students and reported on the top apps for medical students. Below are the five apps that made the cut at both schools.

Epocrates Essentials – This app includes information on thousands of brand, generic and OTC drugs. Features include insurance coverage information, drug-drug interactions for up to 30 medications, pill identification and safety information.

Dynamed – This clinical reference app has an extensive database updated daily and designed for point-of-care situations. Best of all is that medical students can get a free subscription.

iRadiology – This app features over 500 unique cases searchable by organ system and pathology. Users can zoom, pan and rotate images by simply touching the screen of their smart phone. The best part is that the app can run without any reception or internet connection.

Unbound Medicine uCentral – This app allows users to access over 20 million journal abstracts via PubMed with links to full text articles. Articles can be shared with peers or saved as favorites.

VisualDx – This app provides users with peer reviewed images of various disease presentations. It also features a customized differential built upon entered symptoms, patient history and key findings. Additional features include management steps, ICD-9 codes, diagnostic pearls and visuals for over 700 drug-induced diseases.

Other apps mentioned included MedCalc, Medscape Mobile, Micromedex, Skyscape and Diagnosaurus.

References:

  1. Dolan, Brian. "Top Five Medical Apps at Harvard Medical School." Mobihealthnews. N.p., 11 Apr. 2011. Web. 16 July 2013.
  2. 2012 Medical App Survey Results. Penn Medical Student Government MSG. N.p., 9 Feb. 2013. Web. 16 July 2013.
  3. Apple Application Store

Tox Talks: Scombroid Poisoning
Nathan Haas, MSIV
Loyola University Chicago

A 60-year-old healthy male presents to the ED at 4pm following a syncopal episode. He states he ate fish from a Chinese restaurant for lunch, and has not felt well since. He developed crampy abdominal pain, a “peppery taste” in his mouth, one episode of vomiting, lightheadedness and shortness of breath about one hour after lunch. Shortly thereafter, the patient had a witnessed syncopal episode without trauma, convulsions or post-ictal confusion. He has no previous history of syncope, and no other past medical history. He has no known food or drug allergies.

Upon examination, his vitals are: Temp: 37.1, HR: 115, BP: 98/71, RR: 18, and O2 saturation 99% on room air. He speaks in full sentences, appears pale, and is in no apparent respiratory distress. His pupils are 3mm bilaterally and responsive to light, and his skin is warm and diaphoretic. His HEENT, cardiac, pulmonary and abdominal exams are otherwise unremarkable.

What is on your differential at this point, and what is your next step in management?

Scombroid poisoning is a histamine-mediated clinical condition associated with consumption of improperly stored fish, and is the most common seafood-associated illness in the United States.1 Many fish species, including tuna, mahi-mahi and swordfish naturally contain histidine, which is converted to histamine at temperatures above 60°F. For this reason, fish improperly stored at warmer temperatures spontaneously develops large quantities of histamine, which is not destroyed by heating or cooking.

Scombroid poisoning, thus, often presents with signs and symptoms similar to an IgE-mediated allergic reaction, and symptoms typically begin within one hour of consumption. Flushing, rash, wheezing, headache, palpitations, cramping and tachycardia may be present. Occasionally, swelling of the face and tongue, bronchospasm or vasodilatory shock may occur.2 Patients often report a “peppery taste” or some form of burning sensation in the oropharynx as well.3

The mainstays of treatment of scombroid poisoning involve histamine antagonists (H1 and/or H2), fluid resuscitation, supplemental oxygen and supportive care. In more severe cases, epinephrine or bronchodilators may be required.

In patients with recent fish consumption with no known fish or dietary allergies who present with acute onset of signs and symptoms similar to anaphylaxis, it is wise to keep scombroid poisoning on the differential diagnosis. One classic complaint relatively specific to scombroid poisoning is a “peppery taste” in the mouth. The mainstay of treatment is histamine antagonists and supportive care.

References:

  1. Fleming LE, Washington G. Scombroid fish poisoning. Shoreland's Travel Medicine Monthly.1998; 2:2.
  2. Morrow JD, Margolies GR, Rowland J, Roberts LJ. Evidence That Histamine Is the Causative Toxin of Scombroid-Fish Poisoning. New England Journal of Medicine. 324.11 (1991): 716-20. Web. 20 July 2013.
  3. Taylor SL, Stratton JE, Nordlee JA. Histamine Poisoning (Scombroid Fish Poisoning): An Allergy-Like Intoxication. Clinical Toxicology. 27.4-5 (1989): 225-40. Web. 20 July 2013.

Teen Suicide in the United States: What Every Emergency Physician Should Know
Casey Grover, MD
David M. Carreon, MSIV
Michael K. Hole, MSIV
Stanford/Kaiser Emergency Medicine

A 14-year-old boy is brought to the ED with a wrist laceration. Accident or suicide attempt?

Self-harm is the third leading cause of death in this age category behind violence and motor vehicle accidents.3 One nationally representative sample suggests 7% of U.S. teens have attempted suicide in the last year, and 2% have made attempts serious enough to require medical attention.2

What features of history can help evaluate for it? What are meaningful screening questions for adolescent suicide? The following is a rank-ordered list of identified odds ratios of suicide.1,2

Previous attempt 67.4
Eating disorder 14.2
Any mood disorder 9.8
Cluster B personality disorder 8.5
Any psychiatric disorder 9.4
Substance abuse 7.2
Sleep ≤4 hours 6.5
Loss in the family 5
Conduct disorder 4.6
Family history of suicide 4
Anxiety disorder 2.8

The patient interview is ideally done privately (e.g., away from parents and out of a hallway). Even with ideal conditions, deception is likely with many of the questions, so most of these should be considered “screening” questions: “Yes” is significant while “No” doesn’t rule it out.

“Previous attempt” is the most important one on the list. While there is a paucity of evidence on suicide in general and teen suicide specifically, this theme seems to come up again and again and it far outweighs the other factors. This is the most important risk factor. It is also important to note the type of attempt; methods are often repeated, so highly lethal methods (hanging, jumping, shooting) should be of particular concern.

Psychological stress of any kind seems to be another broad category that puts patients at risk: abuse, neglect, death in the family, homosexuality in an unsupportive context and psychiatric disorders (especially eating disorders). Alcohol use is quite common amongst teens (46% used alcohol in the past 30 days), and also confers a rather high risk.

In addition to these, there are the traditional factors identified in adults which carry over. Junhke has adapted the SADPERSONS pneumonic to child and adolescent applications: Sex (male), Age (old teens > young teens), Depressed, Previous attempt, Ethanol/drug use, Rational thinking loss, Social support lacking, Organized plan, Negligent parenting/family stress, School problems.4

Suicidality is surprisingly common amongst teenagers and is an important issue in the emergency department. In general, the list of risk factors is similar to adults, but one should not forget about challenges and risks specific to teenage years like family stress, substance use, sleep and eating disorders.

References:

  1. Bridge JA, Goldstein TR, Brent DA. Adolescent suicide and suicidal behavior. J Child Psychol Psychiatry. 2006;47(3-4):372-94.
  2. Fitzgerald CT, Messias M, Buysse DJ. Teen Sleep and Suicidality: Results from the Youth Risk Behavior Surveys of 2007 and 2009. J Clin Sleep Med. 2011;7(4): 351–356.
  3. Suicide Trends Among Youths and Young Adults Aged 10-24 Years – United States, 1990-2004. CDC Morbidity and Mortality Weekly Report. 2007;56(35):905-908. http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5635a2.htm.
  4. Junhke GA. The adapted-SAD PERSONS: a suicide assessment scale designed for use with children. Elementary School Guidance & Counseling. 1996; 30:4.