Markovchick Vincent J., Pons Peter T., Bakes Katherine M.(ed.) Emergency medicine secrets. 5th ed
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CONTRIBUTORSx
Harold Thomas, MD
Professor, Department of Emergency Medicine,
Oregon Health and Sciences University, Portland,
Oregon
Ronald R. Townsend, MD, MA
Associate Professor, Radiology, University of
Colorado Denver School of Medicine, Aurora;
Medical Director, Radiology, Denver Health Medical
Center, Denver, Colorado
Guy Upshaw, MD
Assistant Professor, Division of Emergency Medicine,
Departments of Surgery/Pediatrics, University of
Colorado School of Medicine; Attending Physician,
Pediatric Emergency Department, Denver Health
Medical Center, Denver; Attending Physician,
Pediatric Emergency Department, The Children’s
Hospital, Aurora, Colorado
Shawn M. Varney, MD, FACEP
Assistant Professor, Military and Emergency
Medicine, Uniformed Services University of the
Health Sciences, Bethesda, Maryland; Emergency
Physician and Medical Toxicologist, Department of
Emergency Medicine, Wilford Hall Medical Center,
Lackland Air Force Base, Texas
Joe E. Wathen, MD
Attending Physician, Pediatric Emergency Medicine,
University of Colorado Denver School of Medicine,
The Children’s Hospital, Denver, Colorado
Robert L. Wears, MD, MS
Professor, Emergency Medicine, University of
Florida, Jacksonville, Florida; Visiting Professor,
Clinical Safety Research Unit, Imperial College,
London, England
Kathryn Wells, MD, FAAP
Assistant Professor, Department of Pediatrics,
University of Colorado Denver School of Medicine;
Attending Physician, Community Pediatrics, Family
Crisis Center, Denver Health Medical Center, Denver;
Consulting Physician, Department of Pediatrics,
Child Protection Team, The Children’s Hospital,
Aurora, Colorado
Andrew M. White, MD, PhD
Assistant Professor, Pediatrics, University of
Colorado Denver School of Medicine; Director,
Pediatric Neurology, Denver Health Medical Center,
Denver; Pediatric Neurologist, The Children’s
Hospital, Aurora, Colorado
Max V. Wohlauer, MD
Resident, Department of Surgery, University of
Colorado Health Sciences Center; Resident,
Department of Surgery, Denver Health Medical
Center, Denver; Resident, Department of Surgery,
University of Colorado Hospital, Aurora, Colorado
Stephen J. Wolf, MD
Associate Professor, Emergency Medicine, and Dean,
Advanced Studies, Office of Undergraduate Medical
Education, University of Colorado Denver School of
Medicine, Aurora; Director, Residence in Emergency
Medicine, Denver Health Medical Center, Denver,
Colorado
Richard E. Wolfe, MD
Associate Professor of Medicine, Harvard Medical
School; Chief, Department of Emergency Medicine,
Beth Israel Deaconess Medical Center, Boston,
Massachusetts
Allan B. Wolfson, MD
Professor of Emergency Medicine, University of
Pittsburgh, Pittsburgh, Pennsylvania
Eric A. Wong, MD
Resident Physician, Medicine, Harvard Medical
School; Assistant Resident, Emergency Medicine,
Beth Israel Deaconess Medical Center, Boston,
Massachusetts
Shan Yin, MD, MPH
Instructor, Pediatric Surgery, University of Colorado
Denver School of Medicine; Fellow, Rocky Mountain
Poison and Drug Center, Denver Health Medical
Center, Denver; Instructor, Emergency Medicine,
The Children’s Hospital, Aurora, Colorado
William F. Young, Jr., MD
Associate Professor, Emergency Medicine, University
of Kentucky; Associate Professor, Emergency
Medicine, University of Kentucky Chandler Medical
Center, Lexington, Kentucky
Richard D. Zallen, DDS, MD
Director, Dentistry and Oral Maxillofacial Surgery,
Denver Health Medical Center, Denver, Colorado
This book is designed to be read by all students and practitioners of emergency medicine, both
novice and experienced. As emergency medicine continues to evolve as a specialty, we have
added several new chapters to our fifth edition and enhanced the format and referencing of
questions. With difficulty, we have also selected the 100 Top Secrets from more than 220
submitted by authors. We hope this continues to be a valuable and enjoyable method of
providing information and knowledge. Knowing some of the important questions about a
particular presentation or problem is the first step to obtaining the answers needed at the
patient’s bedside. However, medicine is nothing if not humbling, and knowledge alone does not
treat all that ails. Listen to your patients and make them feel heard. Getting the right diagnosis
can be invigorating, but impacting a life confirms our calling.
Vincent J. Markovchick, MD, FAAEM, FACEP
Peter T. Pons, MD, FACEP
Katherine M. Bakes, MD
PREFACE
xi
1
TOP 100 SECRETS
These secrets are 100 of the top board alerts. They summarize the concepts,
principles, and most salient details of emergency medicine.
1. When formulating the differential diagnosis, ask “What is the most serious possible cause
of this patient’s presenting signs and symptoms?”
2. When uncertain of the diagnosis, communicate this truthfully to the patient and indicate it
in the final ED diagnosis.
3. Before discharging a patient from the ED, ask, “Why did the patient come, and have
I made the patient feel better?”
4. Familiarity with the indications and limitations of rescue airway devices is essential.
5. Preoxygenation is a critical component of rapid sequence intubation because it will
prevent significant hypoxia despite several minutes of apnea during the intubation
process.
6. When evaluating results of a research paper, the smaller the number needed to treat, the
more effective the intervention or treatment.
7. When in doubt, remember that a p value less than 0.05 is generally considered significant,
the difference found by chance alone being 1 in 20.
8. Consider HIV/AIDS in patients at risk who present with an illness or infection,
particularly those with opportunistic infections or extreme presentations of common
diseases.
9. In febrile patients, a white blood cell or band count is rarely useful in differentiating
between bacterial and viral illnesses.
10. A foreign body in the airway should be suspected in a child with sudden onset of
respiratory symptoms and lack of response to appropriate treatment.
11. The diagnosis of gastroenteritis cannot be made without the presence of both vomiting
and diarrhea.
12. Spinal epidural abscess should be suspected as the cause of back pain in immunocom-
promised patients and IV drug users who present with localized spinal tenderness and
fever.
13. An afferent pupillary defect points to a defect of the retina or optic nerve.
14. Perilimbic flush suggests iritis or glaucoma, not conjunctivitis.
15. When a mandible fracture is suspected, a panoramic radiograph of the mandible is the
least expensive and most accurate film to assess the patient.
TOP 100 SECRETS2
16. Documenting adherence to evidence-based guidelines is helpful in defending against a
malpractice claim.
17. In patients with a high suspicion for bacterial meningitis, administer antibiotics promptly
before the lumber puncture is performed and after blood cultures are obtained.
18. Consider Kawasaki’s disease in children presenting with 5 days of fever.
19. The initial objectives in treating an asthma or chronic obstructive pulmonary disease
(COPD) exacerbation are to relieve significant hypoxemia (oxygen), reverse airflow
obstruction (b-agonists 1 ipratropium), and to reduce of the likelihood of recurrence
(corticosteroids).
20. There is no increased risk for a serious bacterial illness in a child with a simple febrile
seizure.
21. Continuous positive airway pressure (CPAP) or bi-level positive airway pressure
(BiPAP) may well reduce the need for endotracheal intubation in both the ED and
prehospital arenas.
22. The most important tool in assessing patients in whom you suspect ischemic heart
disease is the history. The second most important tool is the history. The third most
important tool is, well, you get the picture.
23. Serum lactate is a useful marker to assess the extent of systemic hypoperfusion and
response to resuscitation.
24. It is not always necessary to identify a dysrhythmia prior to treating it. Assume all wide
complex tachycardia with hemodynamic instability is ventricular tachycardia (VT).
25. An external pacemaker can be used if a permanent pacemaker malfunctions.
26. The diagnosis of atrial fibrillation (AF) can be made clinically by palpating a peripheral
pulse and simultaneously auscultating the heart or visualizing the cardiac rhythm; AF is
the only dysrhythmia that results in a pulse deficit (fewer beats palpated than observed or
auscultated).
27. Every ED should have an interdisciplinary evidence-based guideline for the management of
acute stroke.
28. Do not acutely lower the mean arterial pressure (MAP) more than 20% to 25% in patients
with hypertensive encephalopathy.
29. It is not necessary to gradually empty the bladder when treating an episode of acute
urinary retention.
30. The indications for emergency dialysis are acute pulmonary edema, life-threatening
hyperkalemia, and life-threatening intoxication or overdose by agents normally
excreted by the kidneys.
31. When a patient with end-stage renal disease presents with shortness of breath,
volume overload is by far the most common cause, even when physical examination and
chest X-ray are not diagnostic.
TOP 100 SECRETS 3
32. In a young woman presenting with rash, fever, and diarrhea, consider toxic shock
syndrome and examine for a retained tampon.
33. Doxycycline is the drug of choice for most severe tick-borne infections, and it should be
used empirically and early in the febrile, severely ill patient with a possible tick exposure.
34. A febrile patient returning from the tropics has malaria until proved otherwise.
35. Consider syncope as a cause of fall in a geriatric patient.
36. Patients with myocardial infarction may get symptomatic relief from antacids, and
patients with esophageal disease may get symptomatic relief from nitroglycerin.
Antacids and nitroglycerin are therapeutic medications, not diagnostic tests.
37. Any complaint of abdominal pain in an elderly patient should be taken seriously even if
they have “normal” vital signs and no guarding or rebound tenderness on abdominal
examination.
38. A neutropenic fever is a single temperature greater than 38.3°C and an absolute
neutrophil count less than 1,000/mm
2
.
39. Intussusception occurs between 3 months and 3 years of age.
40. Bilateral retinal hemorrhages in an infant strongly suggest child abuse (shaken baby
syndrome).
41. Ketamine provides sedation, analgesia, and amnesia while protecting the cardiovascular
status and airway reflexes, making it an ideal agent for procedural sedation in children.
42. Because of the fast helical computed tomography (CT) scanners of today, many infants
and children can undergo this diagnostic procedure without sedation.
43. Mesenteric ischemia should be considered in any patient who has severe abdominal pain
out of proportion to the physical examination, often requiring large doses of narcotics.
44. Dermal exposure or ingestion of hydrofluoric acid can result in profound hypocalcemia,
hypomagnesemia, and hyperkalemia.
45. The most important action to take in the event of an attack of weapons of mass
destruction is simply self-protection by donning appropriate personal protective equipment.
46. Sodium bicarbonate (1–2 mEq/kg) should be considered for all poisoned patients with
ventricular dysrhythmias or a wide QRS.
47. Secure the airway early in the management of patients with significant soft-tissue neck
injuries.
48. Consider a computed tomography angiography (CTA) of the neck in patients with facial
or cervical spine fractures.
49. Hypotensive, tachycardic patients with penetrating chest trauma should be immediately
evaluated for tension pneumothorax and pericardial tamponade because emergent
treatment can be life-saving.
TOP 100 SECRETS4
50. A suicide attempt should be considered in patients with illogical explanations for
serious accidents.
51. Analyzing a mass gathering will allow informed decisions about the needed levels of
staffing and equipment necessary to provide on-site care.
52. A CT scan for appendicitis is “negative” only if the entire appendix has been visualized
and is normal.
53. Abdominal aortic aneurysm (AAA) can mimic renal colic.
54. Helical CT is the radiologic modality of choice for diagnosing ureteral calculus.
55. Consider testicular torsion in any male with lower abdominal pain.
56. Early goal-directed therapy in patients with severe sepsis reduces short-term mortality
by 10% to 20% compared with an unstructured treatment regimen.
57. Culture and antibiotics are not indicated in non-immunocompromised patients with a
cutaneous abscess.
58. Necrotizing fasciitis should be considered in any patient with a soft-tissue infection who
has pain and tenderness out of proportion to the visible degree of cellulitis.
59. If using antibiotics to treat abscesses, assume Methicillin-resistant Staphylococcus
aureus (MRSA) as the causative agent.
60. Amphetamine and cocaine toxicity should be treated with IV benzodiazepine in incremental
doses titrated to adequate control of heart rate, blood pressure (BP), and temperature.
61. b-blockers are contraindicated in the treatment of stimulant toxicity because they may
potentiate alpha effects and cause coronary artery vasoconstriction and hypertension.
62. No diagnostic studies are indicated in an asymptomatic patient exposed to smoke in a
nonenclosed space.
63. In the presence of carbon monoxide (CO), pulse oximetry will yield a falsely elevated
reading.
64. A BP greater than 140/90 in a pregnant woman is suspicious for preeclampsia.
65. A pregnant woman with hypertension and seizures should be treated with IV magnesium
sulfate and consideration of emergent delivery of the fetus.
66. The most deceptive of serious hand injuries is the high pressure injection injury from
a hydraulic paint or oil gun because despite a seemingly innocuous appearance on
initial presentation, these injuries require aggressive, surgical management.
67. When allowing a patient to leave against medical advice, consideration of the patient’s
ability to pay is not part of the equation. Only the risks, benefits, and patient’s ability
to understand the risks and benefits are important.
68. Be aware of the long-term cancer risk of patients exposed to diagnostic radiation,
particularly those who are young or have had multiple studies.
TOP 100 SECRETS 5
69. With few exceptions, procedures performed in the ED can be done with fewer
complications and greater success using ultrasound guidance.
70. Any elderly patient with flank, back, abdominal pain, hypotension, syncope, or
pulseless electrical activity (PEA) should have an emergency ultrasound examination to
evaluate for an AAA.
71. IV bolus administration of epinephrine to a patient with an obtainable BP and pulse can
result in ischemic cardiac pain, hypertension, supraventricular tachycardia (SVT), and VT.
72. Examine every patient with urticaria for mucosal edema, stridor, wheezing, and
hypotension to rule out life threats associated with anaphylaxis.
73. A contaminated wound is one with a high degree of bacterial inoculum at the time of
injury and not synonymous with a dirty wound.
74. Determination of pretest probability for venous thromboembolism (VTE) is critical
in knowing when to initiate a diagnostic work-up and how to interpret your test
results.
75. A D-dimer assay is only useful to exclude thromboembolic disease in patients with a low
pretest probability.
76. The problem of “error” in medicine, and the adverse events that sometimes follow, are
problems of psychology and engineering, not of medicine.
77. Emergency medicine, by its nature, has more failure-producing conditions than any other
specialty in medicine.
78. CT of the head will identify 95% of patients with subarachnoid hemorrhage. Lumbar
puncture (LP) is recommended for patients with a strong clinical suspicion, despite
a negative CT of the head.
79. The patient with a posterior nasal packing in place must be monitored in the hospital for
recognition of hypoxia or apnea secondary to stimulation of the nasopulmonary reflex.
80. In almost all cases, trauma patients with unstable vital signs and a positive ED-focused
abdominal sonography for trauma (FAST) examination for free fluid should go directly to
laparotomy.
81. In patients with hyponatremia, to avoid central pontine myelinolysis, serum sodium
should never be raised by more than 0.5 mEq/hr or 12 mEq in 24 hours.
82. Consider a retropharyngeal space infection in a young child presenting with a history of
fever, refusal to drink, sore throat, and reluctance to move their neck.
83. The concomitant ingestion of ethanol (ETOH) with methanol or ethylene glycol protects
against toxic metabolites.
84. Myocarditis should be considered in a patient with a sustained, unexplained tachycardia.
85. Suspect ectopic pregnancy when there is no evidence of intrauterine pregnancy (IUP)
by transvaginal ultrasound and the quantitative human chorionic gonadotropin (HCG)
concentration is greater than 2000 IU/L.
TOP 100 SECRETS6
86. In a lucid patient with blunt abdominal trauma, the clinical examination is the best
guide for selection of diagnostic tests.
87. Obtain a CT scan of the head on any patient on warfarin (Coumadin) with even a
minor head trauma.
88. A single negative abdominal ultrasound alone does not reliably exclude significant
intraperitoneal injury.
89. Children manifest shock later than adults with the same percentage of blood loss, yet
decompensate more quickly once this critical volume is lost.
90. In the case of vascular and/or skin compromise of a deformed limb, urgent realignment
and splinting of the involved extremity should precede radiography.
91. Always exclude associated fractures of the spine and lower extremities in patients with
calcaneal fractures.
92. Never restrain a patient in the prone position; restrain on their side to minimize risks of
aspiration and sudden death.
93. Consider domestic violence in women with depression, suicidal ideations, chronic pain,
psychosomatic complaints, or multiple ED visits.
94. As little as 2 weeks of chronic steroid use (prednisone . 20 mg/day) will cause
adrenal suppression, making a patient more prone to adrenal crisis.
95. Lightning strike is the one exception to the usual multicasualty incident (MCI) triage
rules: The first priority should go to those who are not breathing and not moving
because only those who present in cardiac arrest are at high risk of dying.
96. The NEXUS criteria are 99.6% sensitive and 12.9% specific for significant cervical spine
injuries in adults.
97. Follow potassium closely when treating patients with insulin.
98. Glucose should not be withheld due to the unfounded fear of precipitating Wernicke
Korsakoff’s syndrome.
99. Zoos usually keep antivenin on hand for the exotic venomous animals in their collections.
100. Transient ischemic attack (TIA) is a harbinger of early acute stroke (up to 10% in first
48 hours).
7
CHAPTER 1
DECISION MAKING IN EMERGENCY
MEDICINE
Vincent J. Markovchick, MD, FAAEM, FACEP
I. DECISION MAKING IN EMERGENCY MEDICINE
1. Is there anything unique about emergency medicine?
Although there is significant crossover between emergency medicine and all other clinical
specialties, emergency medicine has unique aspects that make it different, such as the
approach to patient care and the decision-making process.
2. Describe the conventional method of evaluating a patient.
A comprehensive history, physical examination, routine laboratory diagnostic studies,
special diagnostic procedures, and the formulation of a problem-oriented medical record
and rational course of therapy constitute the ideal approach to patient care because it is
so comprehensive.
3. Why is the conventional methodology not ideal for use in the ED?
Even though in retrospect only 10% to 20% of patients presenting to an ED truly have
emergent problems, it must be presumed that every patient who comes to an ED has an
emergent condition. Therefore, the first and most important question that must be
answered is: “What is the life threat?” The conventional approach does not ensure an
expeditious answer to this question. Time constraints also impede the use of conventional
methodology in the ED.
4. How do I identify the life-threatened patient?
Three components are necessary to quickly identify the life-threatened patient:
n
A chief complaint and a brief, focused history relevant to the chief complaint.
n
A complete and accurate set of vital signs in the field and in the ED that are accurately
taken and critically interpreted.
n
An opportunity to visualize, auscultate, and touch the patient.
5. What is so important about the chief complaint?
The chief complaint, which sometimes cannot be obtained directly from the patient but must
be obtained from family members, observers, emergency medical technicians (EMTs), or
others at the scene, will immediately help categorize the general type of problem (e.g., cardiac,
traumatic, respiratory).
6. Why are vital signs important?
Vital signs are the most reliable, objective data that are immediately available to ED personnel
provided they are accurately taken and critically interpreted. Vital signs and the chief
complaint, when used as triage tools, will identify the majority of life-threatened patients.
Familiarity with normal vital signs for all age groups is essential.
7. What are the determinants of (normal) vital signs?
Age, underlying physical condition, medical problems (e.g., hypertension), and current
medications (e.g., b-blockers) are important considerations in determining normal vital signs
for a given patient. For example, a well-conditioned, young athlete who has just sustained
major trauma and arrives with a resting, supine pulse of 80 beats per minute must be
presumed to have significant blood loss because the normal pulse is probably in the range of
40 to 50 beats per minute.