Chapter 1: Emergency Medicine

You get a call from a panicked mother because her 4-year-old took some of her theophylline. She thinks it may have been as many as 10 pills but is not clear on the actual number. She is about 35 minutes from the hospital.

Question 1.1.1 Your advice to her is:

A) Give ipecac to promote stomach emptying and reduce theophylline absorption.

B) Do not give ipecac and proceed directly to the hospital.

C) Call poison control and then proceed to the hospital.

D) Breathe deeply and calm down; theophylline is harmless.

Answer 1.1.1 The correct answer is "B." Do not give ipecac but proceed to the hospital. "A" is incorrect for a couple of reasons. First, ipecac is not a particularly effective method of emptying gastric contents. More importantly, if the patient should start to seize while vomiting as a result of the ipecac, she could aspirate the vomitus causing an aspiration pneumonitis. "C" is incorrect because you do not want to delay definitive treatment. You can call poison control while the patient is on the way.

The patient arrives in your emergency department (ED). She is alert but with a tachycardia of 160 beats per minute and a stable blood pressure (BP). The ingestion occurred about 50 minutes ago. You contemplate gastrointestinal (GI) decontamination.

Question 1.1.2 Which of the following statements is true about gastric lavage?

A) Except in extraordinary circumstances it should only be done in the first hour after an overdose.

B) Patients who have had gastric lavage have higher incidence of pulmonary aspiration than patients who have not.

C) Patients who undergo gastric lavage have a higher incidence of esophageal perforation.

D) It can push pill fragments beyond the pylorus.

E) All of the above are true.

Answer 1.1.2 The correct answer is "E." All of the options are true. Generally, the efficacy of gastric lavage is limited. Outcome data do not support the use of gastric lavage after the first hour. In a particularly severe overdose or in an overdose that is likely to delay gastric emptying (e.g., tricyclic antidepressants), you might want to consider lavage, but such circumstances are unusual. Gastric lavage increases the risk of aspiration, esophageal perforation, and can push pill fragments beyond the pylorus.

Question 1.1.3 After careful consideration, you decided not to lavage. She is now 55 minutes after the ingestion. The next best step to take in this patient is to:

A) Check blood theophylline levels and refer for hemodialysis if markedly elevated.

B) Administer 1 g/kg of charcoal with sorbitol.

C) Prophylactically treat this patient for seizures using lorazepam.

D) Prophylactically treat this patient for seizures using phenytoin.

E) Call the Child Life Activities Therapist to distract the child while you settle in for a 4-hour observation period.

Answer 1.1.3 The correct answer is "B." Giving charcoal is likely helpful only within the first hour after ingestion. "A" is incorrect because the patient's situation could deteriorate by the time blood levels return. "C" and "D" are incorrect because seizure prophylaxis is not indicated in this patient. Although seizures are a major manifestation of theophylline toxicity, they are more likely to occur in patients who take theophylline chronically and have toxic blood levels. Acute ingestions are less worrisome. Observation alone ("E") is not the best choice here.

Question 1.1.4 For which of these overdoses is charcoal NOT indicated?

A) Acetaminophen.

B) Aspirin.

C) Iron.

D) Digoxin.

E) Opiates.

Answer 1.1.4 The correct answer is "C." Charcoal will not bind iron. Charcoal will also not bind Caustics/corrosives, Heavy metals, Alcohols, Rapid-onset cyanide, Chlorine (or iodine), Other insoluble tablets, Aliphatics (hydrocarbons), or Laxatives (mnemonic: CHARCOAL). Some of you may have answered "A." Theoretically, charcoal could interfere with the action of N-acetylcysteine, the antidote for acetaminophen ingestion by absorbing it. However, this is more of a theoretical concern than an actual one. First, the drugs should be used at different times. Charcoal should be given immediately, while N-acetylcysteine is given only after 4-hour levels are available. Second, the doses of N-acetylcysteine recommended are quite high, and you can give a higher dose if you will be using it with charcoal. Finally, intravenous (IV) N-acetylcysteine is available and is obviously not affected by charcoal. "B," "D," and "E" are all incorrect. While we do have antidotes for digoxin and opiates (Digibind, naloxone), charcoal is still indicated to reduce absorption within the first hour.

Objectives: Did you learn to…

• Manage a patient with an acute ingestion?

• Describe the appropriate use of gastric lavage and charcoal administration?

• Identify situations where charcoal may not be indicated?

Oh no. Godzilla is attacking Tokyo. And this time it is with weapons of mass destruction. Which of the following properly describes the isolation requirements of a patient with pulmonary anthrax?

A) No isolation necessary. The patient may be in the same room with an uninfected patient.

B) Respiratory isolation only.

C) Respiratory and contact isolation.

D) Negative pressure room (such as with tuberculosis) + contact isolation.

The correct answer is "A." Pulmonary anthrax is not transmitted person to person. Contact isolation is indicated in those with cutaneous anthrax and GI anthrax (where diarrhea may be infectious).

Godzilla is not done yet… Which of the following drugs should be used as prophylaxis against inhaled anthrax should exposure to aerosolized spores be documented?

A) A first-generation cephalosporin.

B) Trimethoprim/sulfamethoxazole.

C) Ciprofloxacin.

D) A third-generation cephalosporin.

The correct answer is "C." Fluoroquinolones are the drugs of choice when treating those exposed to anthrax. Doxycycline may also be used. Cephalosporins and TMP/SMX are not active against anthrax.

Godzilla, frustrated by his failed anthrax attack, is now spreading smallpox. Which of the following is NOT true about smallpox?

A) Isolation is best done at home if possible.

B) The patient is infectious until he or she becomes afebrile.

C) All lesions are generally in the same stage of evolution, unlike what is seen in varicella.

D) Smallpox immunization causes an encephalitis in 1:300,000 of which 25% of cases are fatal.

The correct answer is "B." The patient is infectious until all lesions crust over and infectivity has nothing to do with the presence or absence of fever. "A" is true. Isolation is best done at home since this will limit spread (those in the household have likely already been exposed). "C" is also true; all lesions are in a similar state of evolution. Finally, "D" is true and is the reason we do not currently immunize against smallpox—well, that and the fact we eradicated it (Way to go, humans!).

A 22-year-old female presents to the ED with an overdose. She has a history of depression, and there were empty bottles found at her bedside. The bottles had contained clonazepam and nortriptyline. The patient is unconscious with diminished breathing and is unable to protect her airway.

Question 1.2.1 The BEST next step is to:

A) Intubate the patient.

B) Begin gastric lavage and administer charcoal.

C) Administer flumazenil, a benzodiazepine antagonist, to awaken her and improve her respirations.

D) Administer bicarbonate.

E) Administer lipid emulsion.

Answer 1.2.1 The correct answer is "A." This patient should be intubated. Remember in any emergency situation that the ABCs (airway, breathing, and circulation) are the priority. "B" is incorrect because, as noted earlier, patients who undergo gastric lavage have a higher incidence of pulmonary aspiration—an even greater concern in the obtunded patient. In fact, airway protection is MANDATORY before undertaking lavage. "C" is incorrect. Flumazenil will reverse the benzodiazepine. However, we know from experience that seizures in patients who have had flumazenil are particularly difficult to control. This would be particularly problematic in a patient with a mixed overdose, such as with a tricyclic, where seizures are common. Thus, it is recommended that flumazenil be used only as a reversal agent after procedural sedation in patients who are not on chronic benzodiazepines. "E" is incorrect. Lipid emulsion refers to the liquid fatty acids given as part of total parenteral nutrition and theoretically can be used to bind fat-soluble drugs in the blood. Case series support consideration of lipid emulsion for calcium channel blocker, beta-blocker, tricyclic antidepressant overdose, and other fat-soluble drugs but only in cases of refractory cardiac arrest or cardiovascular collapse—and certainly not before the airway has been secured.

You notice that the patient begins to have an abnormal tracing on the cardiac monitor, so you order an ECG.

Question 1.2.2 Which of the following findings would you expect to find in a tricyclic overdose?

A) Normal QRS complex.

B) Second- and third-degree heart block.

C) Widened QRS complex.

D) Sinus tachycardia.

E) Any of the above.

Answer 1.2.2 The correct answer is "E." All of the above findings can be seen with a tricyclic overdose. In fact, the most common presenting rhythm is a narrow-complex sinus tachycardia. As toxicity progresses, you can see a prolonged PR interval, a widened QRS complex, and a prolonged QT interval. A QRS >100 ms is predictive of seizures and QRS >160 ms is highly predictive of ventricular arrhythmia in patients with a tricyclic antidepressant overdose. Heart blocks (second and third degree) herald a poor outcome and may be seen late in the course. Asystole is not a primary rhythm in tricyclic overdose and tends to reflect the end stage of another arrhythmia.

YIKES!! The patient becomes unresponsive and you look at the monitor. You obtain an ECG which shows the following: (Fig. 1-1).

FIGURE 1-1. ECG for patient in question 1.2.3.

Question 1.2.3 What is the patient's rhythm?

A) Monomorphic ventricular tachycardia.

B) Sinus tachycardia with a bundle branch block.

C) Paroxysmal supraventricular tachycardia.

D) Torsades de pointes.

E) Third degree heart block.

Answer 1.2.3 The correct answer is "D." This is torsades de pointes (in French it literally means "twisting of the points," but in every language it means "physician's stress test"), which is a subtype of polymorphic ventricular tachycardia. Torsades de pointes can be recognized by the varying amplitude of the complex in a somewhat regular pattern. "A" is incorrect because the complexes are not monomorphic. "B" is incorrect for two reasons. First, there are no P waves visible. Second, sinus tachycardia should not have varied amplitude. "C" is incorrect because, again, there are no P waves and the complexes are polymorphic. "E" is incorrect because there are no P waves.

Question 1.2.4 This patient needs treatment post haste. After taking care of the ABCs, what is the ONE BEST drug for the treatment of this arrhythmia in a patient with a tricyclic overdose?

A) Esmolol.

B) Lidocaine.

C) Sodium bicarbonate.

D) Procainamide.

E) Amiodarone.

Answer 1.2.4 The correct answer is "C." The treatment of choice for arrhythmias in patients with a tricyclic overdose is sodium bicarbonate. Raising the pH and administering sodium seem to "prime" the sodium channels in the heart, reversing the toxicity of the tricyclic. Procainamide ("D") and quinidine should not be used because they act in similar fashion to tricyclics and may worsen the problem. Lidocaine ("B") can be used as can amiodarone ("E"), but they are not the best choices. Beta-blockers such as esmolol ("A") can worsen hypotension and should be avoided.

This is not your patient's lucky day. She begins to seize after the administration of the bicarbonate.

Question 1.2.5 The treatment of choice for this seizing patient is:

A) Lorazepam.

B) Repeat the bolus of sodium bicarbonate and start a bicarbonate drip.

C) Phenytoin (Dilantin).

D) Fosphenytoin (Cerebryx).

E) None of the above.

Answer 1.2.5 The correct answer is "A." Benzodiazepines are the treatments of choice in tricyclic-induced seizures. While most seizures are self-limited, it is important to control seizures because the resultant acidosis can worsen tricyclic toxicity (beyond the fact that prolonged seizures can cause CNS injury). "B" is incorrect. This patient is already alkalinized, and although sodium bicarbonate is the preferred therapy for tricyclic-induced cardiovascular toxicity, sodium bicarbonate is not particularly effective in tricyclic-induced seizures. "C," phenytoin, can be used, but benzodiazepines and phenobarbital should be administered first if possible. In addition to not working well as an antiepileptic drug in tricyclic overdose, phenytoin is also a class Ib antiarrhythmic, which may further prolong the QRS and worsen the cardiac toxicity of the tricyclic. "D" is incorrect for two reasons. First, since fosphenytoin is metabolized to phenytoin, the concern about efficacy applies. Second, fosphenytoin is a prodrug and requires adequate circulation and renal and hepatic function to be converted into active drug. If our patient becomes hypotensive with poor liver and renal perfusion, adequate drug levels might not be achieved. Finally, both phenytoin and fosphenytoin can cause hypotension—not what you need in this unstable patient.

You correct the arrhythmia and stop the seizures, and she is admitted to the intensive care unit.

Objectives: Did you learn to…

• Understand the importance of the A–B–Cs in an unstable patient?

• Describe the role of flumazenil in toxicologic emergencies?

• Manage a tricyclic overdose?

• Recognize ECG findings in a tricyclic overdose?

• Recognize torsades de pointes and its treatment in the context of a tricyclic overdose?

An 18-year-old male presents after a party. He is having alternating episodes of combative behavior interspersed with episodes of coma. He becomes almost apneic during the episodes of coma. He has alternating bradycardia (while in coma) and tachycardia when awake. The patient is also having myoclonic seizures. His serum alcohol level is zero, and his pupils are miotic.

The most likely drug causing this is:

A) Ecstasy (MDMA).

B) GHB (gamma-hydroxybutyrate aka "liquid ecstasy").

C) Methamphetamine.

D) LSD (lysergic acid diethylamine aka "acid").

E) Opiate overdose.

The correct answer is "B." The episodic coma and bradycardia interspersed with episodes of extreme agitation are almost pathognomonic of GHB overdose. GHB intoxication also causes pinpoint pupils. "A" is incorrect because MDMA causes an amphetamine-like reaction with agitation, hypertension, hyperthermia, tachycardia, etc. "C" is incorrect for the same reason. "D" is incorrect because LSD rarely (if ever) causes coma. "E" is incorrect because patients with opiate overdoses are generally somnolent or comatose without interspersed episodes of agitation, although opiate use may also causes miosis (be aware that not all narcotic overdoses are associated with pinpoint pupils). GHB is odorless and has slight salty taste. It has become a drug of choice for "date rape." The toxicity tends to be self-limited and can be treated with intubation if needed along with tincture of time. The half-life is only 27 minutes.

A patient presents to the hospital with a diphenhydramine overdose.

Which of the following signs and symptoms are you likely to find in this patient?

A) Bradycardia, dilated pupils, flushing, and increased bowel sounds.

B) Bradycardia, pinpoint pupils, flushing, and decreased bowel sounds.

C) Tachycardia, dilated pupils, diaphoresis, and increased bowel sounds.

D) Tachycardia, dilated pupils, flushing, and decreased bowel sounds.

E) Tachycardia, pinpoint pupils, flushing, and increased bowel sounds.

The correct answer is "D." This patient has an anticholinergic toxidrome. Toxidromes are symptom complexes associated with a particular overdose that should be immediately recognized by the clinician. Common toxidromes are listed in Table 1-1.

A patient presents to your office with neck pain after a motor vehicle accident. He was restrained and the airbag deployed. He notes that he had some lateral neck pain at the scene. He continues to have lateral neck pain.

Question 1.3.1 Which of the following IS NOT a criterion for clearing the cervical spine clinically?

A) Absence of all neck pain.

B) Normal mental status including no drugs or alcohol.

C) Absence of a distracting injury (such as an ankle fracture).

D) Absence of paralysis or another "hard" sign that could be caused by a neck injury

E) Absence of retrograde amnesia.

Answer 1.3.1 The correct answer is "A." Patients can have lateral neck pain and still have their cervical spines cleared clinically. However, no one will fault you for obtaining radiographs in patients with lateral muscular (e.g., trapezius) neck pain. Patients with central neck pain (e.g., over the spinous processes) DO need imaging (radiographs ± CT) to clear their cervical spine. All of the other criteria are required in order to clinically clear the cervical spine (Table 1-2). These criteria have been validated in both adult and pediatric patients.

The patient's daughter, aged 4 years, was in the same motor vehicle accident and also had her cervical spine cleared by radiograph. However, you get a call from the ED 48 hours after the initial accident that she is paralyzed from just above the nipple line down (never a good thing—you quickly make a mental note to make sure your malpractice insurance premiums are paid up). You review the initial radiographs with the radiologist, which are negative as is a CT of the cervical spine bones done after the onset of the paralysis.

Question 1.3.2 The most likely cause of this patient's paralysis is:

A) Missed transection of the thoracic cord.

B) Conversion reaction from the psychological trauma of the accident.

C) Subarachnoid hemorrhage.

D) SCIWORA syndrome.

E) Guillain–Barre syndrome.

Answer 1.3.2 The correct answer is "D." This likely represents SCIWORA syndrome (spinal cord injury without radiologic abnormality). This occurs from stretching of the cord secondary to flexion/extension-type movement in an accident. Patients with SCIWORA syndrome may be paralyzed at the time of initial presentation (in the event of cord transection) or may have a delayed presentation up to 72 hours after the injury. "A" is incorrect because a cord transection would present with paralysis immediately at the time of injury. "B" is incorrect because this child is 4 years old, and conversion reaction is unlikely in children. In addition, conversion reaction IS ALWAYS a diagnosis of exclusion. "C" and "E" are incorrect because this is neither the presentation of a subarachnoid hemorrhage (headache, stiff neck, perhaps focal neurologic symptoms) nor of Guillain–Barre syndrome (progressive numbness and weakness from autoimmune myelitis).

Question 1.3.3 The next step in the management of this patient is:

A) Avoid hypotension and hypoxia to prevent secondary insult to the cord

B) Fluid restriction and diuretics to reduce cord edema.

C) Mannitol to reduce cord edema.

D) Neurosurgical intervention to decompress the cord.

E) Lollipop and a gift card for "service recovery."

Answer 1.3.3 The correct answer is "A." Patients with a cord injury should be monitored closely to avoid hypotension and hypoxia, both of which will further damage the already compromised spinal cord. Neither diuretics ("B") nor mannitol ("C") will be useful in this situation. "D" is incorrect because the process of SCIWORA involves stretching of the cord (and subsequent dysfunction) rather than cord compression such as would be seen with a bony injury. "E" might be the right choice if you are taking this test as a "patient experience expert" instead of a doctor; but doctors should choose "A."

Question 1.3.4 The father is, understandably, irate that his child is now paralyzed. You can tell him that the natural history of SCIWORA syndrome in THIS CHILD is likely to be the following:

A) Continued paralysis with the necessity of long-term, permanent adaptation to the injury.

B) Progression of the injury over the next week to include further paralysis in an ascending fashion.

C) Resolution of paralysis and sensory symptoms over the next several months.

D) Resolution of all symptoms except sensory symptoms of the next several months.

E) Large lawsuit payout on the way. Do not pass go; do not collect $200; go directly to a malpractice attorney.

Answer 1.3.4 The correct answer is "C." Generally, patients with SCIWORA syndrome regain their strength and sensory abilities over time. However, this depends on when they present with symptoms! Patients who present with paralysis right after the accident may have complete cord transection and thus will not regain function. For this reason, it is important to obtain an MRI on all patients with SCIWORA syndrome (and any trauma-induced paralysis for that matter).

Objectives: Did you learn to…

• Clinically "clear" the cervical spine and decide when to order cervical spine radiographs?

• Understand the physiology, natural history, and management of SCIWORA syndrome?

A patient with an extensive history of alcohol use presents to the ED after drinking a bottle of automobile winter gas treatment (Rothschild Vintage, 1954). He is intoxicated, has a headache, and describes a "misty" vision, "like a snowstorm" (if you live in southern Florida or California, call one of us in Iowa for a description). He is tachycardic and tachypneic. You start an IV and administer saline. You obtain a blood gas, which shows a mild metabolic acidosis.

Question 1.4.1 A metabolic acidosis is consistent with all of the following ingestions EXCEPT:

A) Ethylene glycol.

B) Methanol.

C) Ethanol (e.g., vodka, gin).

D) Petroleum distillates (e.g., non-alcohol containing gasoline products).

Answer 1.4.1 The correct answer is "D." Ethylene glycol, methanol, and ethanol can all cause a metabolic acidosis. Hydrocarbons (e.g., gasoline products) do not cause a metabolic acidosis. The main manifestation of hydrocarbon toxicity is secondary to the inhalation and aspiration of the hydrocarbon and the resulting pneumonitis.

This patient's electrolytes are as follows: sodium 135 mEq/L, bicarbonate 12 mEq/L, chloride 108 mEq/L, BUN 12 mg/dL, Cr. 1.0 mg/dL.

Question 1.4.2 This patient's anion gap is:

A) 13.

B) 15.

C) 23.

D) Unable to calculate the anion gap with the information provided.

Answer 1.4.2 The correct answer is "B." By convention, the anion gap is calculated without using a major cation, potassium. Thus, the anion gap is calculated as follows:

In this patient, the anion gap = 135 – (108 + 12) = 15.

The normal anion gap is typically considered to be 12 or less. However, since albumin is the major unmeasured anion in the serum, the anion gap should be adjusted for hypoalbuminemia. Every 1 g decrease in albumin will increase the anion gap by about 3. Therefore, you should subtract (3 × [normal albumin-actual albumin]) to get the "real" anion gap. The normal albumin is considered to be 4. So, let us say we calculate an anion gap of 16 but the albumin is 2. In this case the corrected anion gap will be (16 – [3 × (4 – 2)] = 16 – 6), or 10.

Question 1.4.3 All of the following are causes of an anion gap acidosis EXCEPT:

A) Lactic acidosis.

B) Diabetic ketoacidosis.

C) Renal tubular acidosis.

D) Uremia.

E) Ingestions such as methanol.

Answer 1.4.3 The correct answer is "C." See Table 1-3 for more on causes of anion gap acidosis.

Question 1.4.4 Which of the following findings IS NOT frequently seen in patients with methanol ingestion?

A) Hypopnea.

B) Optic disk abnormalities.

C) Abdominal pain and vomiting.

D) Basal ganglia hemorrhage.

E) Meningeal signs, such as nuchal rigidity.

Answer 1.4.4 The correct answer is "A." Hypopnea is not commonly seen in methanol poisoning until the patient is close to death. In fact, the reverse is true. Tachypnea is a frequent finding in methanol overdose. This makes sense. The patient is trying to compensate for a metabolic acidosis by blowing off CO₂. Optic disk abnormalities, abdominal pain and vomiting, basal ganglia hemorrhage, and meningeal signs are all seen as part of methanol toxicity. It is thought that many of these signs and symptoms are secondary to central nervous system (CNS) hemorrhage.

You can test for ethanol at your hospital but do not have a test for methanol on a stat basis and want to be sure that this patient is not just saying he has a methanol ingestion in order to obtain alcohol (a treatment for methanol ingestion—break out the single malt scotch!).

Question 1.4.5 What test is most likely to help you determine if the patient has methanol ingestion?

A) Complete blood cell count (CBC).

B) BUN/creatinine.

C) Liver enzymes.

D) Serum osmolality.

E) Amylase and lipase.

Answer 1.4.5 The correct answer is "D." With a measured serum osmolality, you can calculate the osmolar gap. To do so, subtract the total measured serum osmoles from the osmoles known to be due to ethanol (each 100 mg/dL of ethanol accounts for approximately 22 osmoles). If there is an elevated osmolar gap, it is evidence of a circulating, unmeasured osmole. A normal osmole gap is somewhere between –10 and 20 mOsm/kg.

In this case, for example:

Calculated osmolality = 2(Na) + BUN/2.8 + glucose/18 = 280 + 6 + 8 = 294.

So, osmolar gap = 368 – (294 + 44) = 30.

This means that there are 30 unmeasured osmoles that could, in the clinical context of the case, represent methanol. Thus, we know that the patient did not simply overindulge on ethanol (methanol, such as "gas dry," will make one intensely drunk… but has obvious downsides).

You decide that there is sufficient evidence that this patient has ingested methanol to institute treatment.

Question 1.4.6 Appropriate treatment(s) for this patient include:

A) Fomepizole (4-MP).

B) Acetylsalicylic acid.

C) Ethanol.

D) A and C.

E) All of the above.

Answer 1.4.6 The correct answer is "D." Both Fomepizole (4-MP) and ethanol are used for methanol ingestion. The idea is to slow down the metabolism of the methanol. The toxicity of methanol is caused by formic acid, which is a by-product of methanol metabolism. Ethanol is metabolized by alcohol dehydrogenase, the same enzyme that breaks down methanol. Thus, methanol metabolism is competitively inhibited by ethanol. The same holds true for fomepizole, which is a competitive inhibitor of alcohol dehydrogenase. Fomepizole and ethanol can both be used for ethylene glycol ingestion as well. "B" is incorrect. Acetylsalicylic acid (ASA), or aspirin, has no role in methanol ingestion, and would likely worsen any gastritis or hemorrhaging.

Objectives: Did you learn to…

• Recognize manifestations of alcohol ingestion?

• Identify causes of metabolic acidosis with elevated and normal anion gaps?

• Use the osmolar gap to narrow down the differential diagnosis of metabolic acidosis?

Which of the following has been shown to be useful in beta-blocker overdose when conventional, adrenergic pressors are ineffective?

A) Calcium chloride.

B) Glucagon.

C) Milrinone.

D) High-dose insulin.

E) All of the above.

The correct answer is "E." In beta-blocker overdoses, the following findings may be observed: bradycardia, AV block, hypotension, bronchospasm, nausea, emesis, and hypoglycemia. This is very similar to the presentation of a calcium channel blocker overdose, but calcium channel blocker overdose often lacks bronchospasm and patients are hyperglycemic as insulin release from the islet cells is calcium dependent. When a beta-blocker overdose has been identified, the usual treatments are employed (e.g., IV fluids, vasopressors, airway protection, charcoal). If conventional vasopressors have failed, glucagon in a dose of 3 to 5 mg IV bolus and a drip at 1 to 5 mg/hr may be effective in treating beta-blocker overdose. It is generally preferred over atropine in this situation. Milrinone and other phosphodiesterase inhibitors may also be used but are considered third-line agent. Like-wise, calcium is considered a third-line agent in beta-blocker overdose. Calcium chloride may potentiate the action of glucagon. There is also a growing body of literature supporting use of high dose insulin-euglycemia for beta-blocker, calcium channel blocker, or combination overdoses. The insulin is started at 0.5 units/kg/hr and titrated to as high as 10 units/kg/hr, titrated by hemodynamic improvement (see Clin Toxicol (Phila). 2011;49(4):277–283, for example). Does it seem counterintuitive to give glucagon and insulin? Both appear to mitigate the deleterious effects of beta-blockers on cardiac myocyte metabolism, although the mechanism is not completely understood. Both can be given (usually in sequence with the glucagon first) to the same patient for beta-blocker overdose. Remember to maintain euglycemia if using insulin for beta-blocker or calcium channel blocker overdose.

Which of the following can be used to increase the metabolism of alcohol in an intoxicated patient?

A) IV fluids.

B) Charcoal.

C) Forced diuresis.

D) GABA antagonists such as flumazenil.

E) None of the above.

The correct answer is "E." Drunk patients, no matter how much they annoy you, will just have to sleep it off. The rate of alcohol metabolism is fixed with zero-order kinetics at lower doses (fixed metabolic rate) and first-order kinetics at higher doses (rate proportional to levels). In general, this rate is in the range of 9 to 36 mg/dL/hr with 20 mg/dL/hr being the accepted norm. At this point, there are no available agents to increase the metabolism of ethanol. "B" is incorrect because ethanol is too rapidly absorbed for charcoal to be of any benefit.

The best therapy for seizures secondary to isoniazid ingestion is:

A) Lorazepam.

B) Phenytoin.

C) Pyridoxine.

D) Thiamine.

E) Phenobarbital.

The correct answer is "C." Isoniazid is a vitamin B6 antagonist. Thus, pyridoxine (in massive doses!) is the drug of choice in isoniazid-induced seizures. These seizures are often resistant to conventional therapy. Look for this type of overdose in patients who are being treated for tuberculosis (either active or latent disease).

A family of four comes into your ED after being exposed to carbon monoxide (CO). They were in an idling car and were running the engine and heater to stay warm. You want to get a carboxyhemoglobin level on the whole family but cannot get an arterial blood gas from the youngest child.

Question 1.5.1 What is your response?

A) Check pulse oximetry, and if the oxygen saturation is normal, be reassured.

B) Check end-tidal carbon dioxide.

C) Check a venous carboxyhemoglobin level.

D) Check a venous carboxyhemoglobin and correct for the difference between venous and arterial samples.

Answer 1.5.1 The correct answer is "C." A venous carboxyhemoglobin is just as accurate as an arterial carboxyhemoglobin—in fact, no correction is needed, which is why "D" is wrong—and it is much less painful to draw. "A" is incorrect because the pulse oximeter does not reflect hypoxia in carbon monoxide poisoning. Thus, standard pulse oximetry is useless in determining the carboxyhemoglobin level. "B" is incorrect because end-tidal carbon dioxide is measuring CO₂ and not CO.

Question 1.5.2 When determining which patients need hyperbaric oxygen on the basis of a carboxyhemoglobin level, the level to rely upon is:

A) The carboxyhemoglobin level on arrival to the ED.

B) The carboxyhemoglobin level at 4 hours after exposure.

C) The carboxyhemoglobin level projected to "time zero" (e.g., at the time of exposure).

D) None of the above.

Answer 1.5.2 The correct answer is "C." A major consideration regarding the initiation of hyperbaric oxygen therapy is the patient's clinical situation. More severely ill patients with CO poisoning (e.g., severe acidosis, unconscious, unresponsive) should be considered candidates for hyperbaric oxygen, and some hyperbaric oxygen centers will treat regardless of measured carboxyhemoglobin level in these patients. If the treatment decision is made based on the carboxyhemoglobin level, the level projected to time zero gives the most accurate information about the degree of exposure. The rest of the answers are incorrect.

The father has a headache and a time zero carboxyhemoglobin level of 12%. The mother, who is pregnant, is asymptomatic and has a time zero carboxyhemoglobin level of 18%. Both of the children are asymptomatic. The 6-year-old has a time zero carboxyhemoglobin of level of 18% while the 8-year-old has a level of 23%.

Question 1.5.3 The first step in the treatment of these patients is:

A) Start an IV and administer saline.

B) Start N-acetylcysteine, which is a free radical scavenger.

C) Start continuous positive airway pressure (CPAP) to maximize airflow by keeping the airways from collapsing.

D) Administer 100% oxygen.

E) Intubate the most severe patient, 100% oxygen for the others.

Answer 1.5.3 The correct answer is "D." Because CO competitively binds to hemoglobin in place of oxygen and in fact has greater affinity for hemoglobin than oxygen, high-flow 100% oxygen is the cornerstone of treating CO poisoning. The half-life of CO in a patient breathing room air is approximately 300 minutes; this is reduced to 90 minutes when breathing high flow oxygen and reduced to 30 minutes when breathing 100% hyperbaric oxygen. Thus, the first step in CO poisoning is to administer 100% oxygen. The rest of the answers are incorrect. If the patient is not ventilating well and requires intubation, this would be appropriate, and the FiO₂ should be set to 100%, regardless of the patient's pulse oximetry or arterial oxygen readings. However, in our patients who are breathing without difficulty, there will be no advantage (and much higher risk) to intubation.

Question 1.5.4 Which of the following can be seen with carbon monoxide poisoning?

A) Rhabdomyolysis.

B) Cardiac ischemia.

C) Long-term neurologic sequelae, including dementia.

D) Pulmonary edema.

E) All of the above.

Answer 1.5.4 The correct answer is "E." All of the above can be seen with carbon monoxide poisoning. Additional findings include lactic acidosis, seizures, syncope, and headache. "C" deserves a bit more discussion. Long-term neurologic sequelae can develop from days to months after the exposure and include cognitive deficits, focal neurologic deficits, movement disorders, and personality changes. It appears that using hyperbaric oxygen in the appropriate patient can reduce long-term neurologic sequelae.

Your closest diving chamber is about 90 minutes away and will hold only one patient at a time. You need to make a decision about who to send for hyperbaric oxygen.

Question 1.5.5 Which patient will benefit most from hyperbaric oxygen therapy?

A) Asymptomatic pregnant mother, time zero carboxyhemoglobin of 18%.

B) Asymptomatic 6-year-old, time zero carboxyhemoglobin of 18%.

C) Asymptomatic 8-year-old, time zero carboxyhemoglobin of 23%.

D) Adult male with mild headache only, time zero carboxyhemoglobin level of 12%.

Answer 1.5.5 The correct answer is "A." Generally accepted criteria for hyperbaric oxygen include: mental status changes, asymptomatic carboxyhemoglobin levels >25%, acidosis, cardiovascular disease, and age >60. Obviously, these are relative criteria. An otherwise normal 61-year-old with a mild exposure need not have HBO. Pregnancy is an indication for HBO therapy because fetal hemoglobin has a high affinity for carbon monoxide, with the fetus acting as a "sink" for CO. The high aerobic metabolic activity of fetal development is impacted greatly by exposure to the anaerobic environment created by carbon monoxide.

Question 1.5.6 All of the following are well-established consequences of hyperbaric oxygen EXCEPT?

A) Seizures.

B) Psychosis.

C) Myopia.

D) Ear and pulmonary barotraumas.

E) Direct pulmonary oxygen toxicity.

Answer 1.5.6 The correct answer is "B." All of the rest are found as a result of hyperbaric oxygen. "C," myopia, is actually found in up to 20% of patients being treated with hyperbaric oxygen. It is due to direct toxicity of oxygen on the lens and usually recovers within weeks to months.

Objectives: Did you learn to…

• Diagnose and manage patients with carbon monoxide poisoning?

• Describe complications of carbon monoxide poisoning?

• Identify patients who may benefit from hyperbaric oxygen therapy?

• Describe the complications of hyperbaric oxygen therapy?

A 50-year-old man comes to your ED after being bitten by a stray dog outside your hospital. Apparently, there is a problem with roving packs of feral dogs in your part of town. The bite was unprovoked and is on the abdomen. The patient has no other health history of note and has not taken antibiotics for over a year. There is a 3-cm laceration on the abdomen.

Question 1.6.1 All of the following are true about dog bites EXCEPT:

A) They tend to be primarily crush-type injuries.

B) In general, the infection rate is similar to a laceration from any other mechanism (e.g., knife cut), except on the hands and feet.

C) A common organism in infected dog bites is Staphylococcus aureus.

D) Primary closure of dog bite wounds is an acceptable option (except perhaps on the hands and feet).

E) They always require antibiotics.

Answer 1.6.1 The correct answer is "E." All of the rest are true statements. Dog bites (except, perhaps, for those from teacup poodles named Fifi) tend to be crush injuries (as contrasted with cat bites, which are primarily puncture wounds). The infection rate is about the same as other lacerations. Bites on the hands and feet tend to have a higher rate of infection. Most dog bite infections are polymicrobial with mixed aerobic and anaerobic bacteria. S. aureus is often present, along with other organisms including Pasteurella and Capnocytophaga (say that one ten times fast). Other organisms include Streptococcal species and Gram-negative species. Dog bites do not generally require antibiotic prophylaxis, except under certain circumstances (e.g., present >9 hours after bite, immunocompromised, large, or complicated wound).

Question 1.6.2 You are concerned about rabies prophylaxis. Which of the following is the best next step?

A) Isolate the suspect animal for 3 days.

B) Sacrifice the suspect animal and examine the liver.

C) Administer rabies immune globulin IM.

D) Administer rabies immune globulin IV followed by rabies vaccination series.

E) Administer rabies immune globulin by infiltrating it around the wound followed by rabies vaccination series.

Answer 1.6.2 The correct answer is "E." You should infiltrate rabies immune globulin around the wound and then begin the rabies vaccination series. Infiltrate as much of the immune globulin as possible around the wound and administer the remainder IM at a different site. Do not give more than the recommended dose of immunoglobulin. This can reduce the immunogenicity of the vaccine. "A" is incorrect because animals need to be isolated for 10 days, not 3. "B" is incorrect. If captured, the animal can be sacrificed but the brain should be examined—not the liver. "C" and "D" are both incorrect methods of administering the vaccine and immune globulin. Note that the average incubation period of rabies is 85 days. So, immunizing up to 3 months (90 days) after the bite-event is indicated.

Question 1.6.3 Which of the following requires rabies prophylaxis in all cases?

A) Stray rabbit bites.

B) Stray rat bites.

C) Stray bat bites.

D) Stray squirrel bites.

E) Stray snake bites.

Answer 1.6.3 The correct answer is "C." All bats should be considered rabid unless available for observation and testing. See Table 1-4 for detailed recommendations. Also, see the CDC website for information about rates of infection in wild animals in your area. Of note, and true, there are rabid squirrels in Iowa City, our illustrious home: Google it.

You decide to irrigate this patient's wound.

Question 1.6.4 Which of the following statements is true about irrigating a wound and subsequent risk of wound infections?

A) Povidone-iodine as a 50% irrigation solution (e.g., Betadine) in the wound will decrease the infection rate.

B) Irrigation with normal saline is the only recommended method of cleaning a wound.

C) Irrigation with normal saline and irrigation with tap water are equally effective in reducing wound infection rates.

D) Use of epinephrine with lidocaine in a wound increases the rate of infection.

E) Irrigation of a wound with either alcohol or hydrogen peroxide will reduce the rate of wound infection.

Answer 1.6.4 The correct answer is "C." Infection rates (in the United States) are the same whether the wound is irrigated with normal saline or tap water. "A" is incorrect. Povidone-iodine is toxic to tissue and polymorphonuclear leukocytes and actually may increase infection rates unless a solution of 1% or less is used. Full strength povidone-iodine can be used on intact skin as a cleanser but should not be used in a wound. "B" is incorrect because other solutions (poloxamer 188, balanced salt solutions, etc.) can be used but are more expensive and do not offer any benefit in reduction in infection rates. "D" and "E" are both incorrect. As with povidone-iodine, alcohol may be used for cleaning skin but should be kept out of the wound. It is toxic to tissue and acts a fixative. Hydrogen peroxide is also toxic to tissue and should not be used in open wounds—no matter what grandma says!

Question 1.6.5 How long after a laceration occurs can the wound be closed primarily?

A) 6 hours.

B) 12 hours.

C) 18 hours.

D) 24 hours.

E) Any of the above can be correct depending on the wound.

Answer 1.6.5 The correct answer is "E." There is no arbitrary time limit to when a wound can be closed. Facial wounds may be closed up to 24 hours after injury for cosmetic reasons, while you may not want to close other, contaminated wounds more than 12 hours after injury. Some wounds you may not want to close at all (e.g., bites to the hand, wounds contaminated with grease, wounds contaminated with manure, human bite wounds), rather allowing them to close by secondary intention.

Objectives: Did you learn to…

• Describe the indications for rabies prophylaxis?

• Recognize the issues that arise with animal bites and indications for closure and/or prophylactic antibiotics?

• List recommendations for tetanus prophylaxis?

• Use various wound irrigation solutions for cleansing wounds?

• Decide upon the time frame for wound closure?

A 52-year-old male presents to your ED via ambulance complaining of a headache after a fall. He was working and fell approximately 10 ft. He notes no injury except for head and neck pain. A quick survey reveals that he has a BP of 128/86 mm Hg, pulse 100 bpm, and respirations of 12. There was no loss of consciousness at the scene. He "saw stars" and was clumsy, dazed, and slow at the scene without any focal neurologic deficit. He is now back to his baseline.

Question 1.7.1 A concussion is defined as:

A) Any neurologic symptoms (e.g., clumsy, dazed, or slow) after head injury.

B) Loss of consciousness followed by return to baseline.

C) Loss of consciousness with continued neurologic symptoms.

D) Confusion after head trauma regardless of whether the patient lost consciousness or not.

E) Any traumatic injury to the head.

Answer 1.7.1 The correct answer is "A." A concussion is defined as any neurologic symptom after head trauma. Note that a concussion does not require a loss of consciousness. For this reason, "B" and "C" are incorrect. "D" is incorrect because manifestations of concussion are not limited to confusion but also include protracted vomiting, transient amnesia, slowed mentation, "dizziness," and other neurologic symptoms. "E" is incorrect because by definition, a concussion requires neurologic symptoms.

Your patient opens his eyes spontaneously, follows commands, answers all orientation questions correctly, but appears unsteady when ambulating.

Question 1.7.2 His Glasgow Coma Scale (GCS) is:

A) 5.

B) 10.

C) 14.

D) 15.

E) 20.

Answer 1.7.2 The correct answer is "D." The GCS is a scale used to indicate the severity of neurologic dysfunction and is often applied to victims of head trauma. Remember, however, that it does not predict mortality or morbidity but is only used as a descriptive scale of the patient's current state. Only the maximum score of 15 is considered a normal GCS. There are three components to the GCS, listed in Table 1-5.

Question 1.7.3 In patients with head injury, and independent of other factors, a GCS score of 15 indicates that:

A) The patient does not require a head CT scan.

B) There is essentially no possibility that this patient has an intracranial injury requiring surgical intervention.

C) There is little or no possibility that this patient has any focal intracranial bleed.

D) There is up to a 4% chance this patient will need neurosurgical intervention.

E) None of the above.

Answer 1.7.3 The correct answer is "D." In appropriately selected patients (e.g., those with a significant mechanism of injury), about 18% with a GCS of 15 will have some intracranial lesion, and up to 4% will eventually require neurosurgical intervention. These are generally patients who have a depressed skull fracture but a normal GCS. "A" is incorrect since a normal GCS in and of itself does not allow one to forgo head CT in patients with a significant mechanism of injury. "B" and "C" are also incorrect for the reasons noted earlier. Remember that the GCS is not linear; a GCS of 14 is bad. Patients with a GCS of 14 must have a CT scan—unless another factor in the clinical decision making dictates otherwise (e.g., the finding is pre-existing from dementia or otherwise).

Question 1.7.4 In an adult patient with a significant head injury, which of the following is NOT an indication for a head CT scan?

A) Intoxication with drugs or alcohol.

B) Persistent vomiting.

C) Amnesia or memory deficit.

D) Age greater than 40.

E) Seizure.

Answer 1.7.4 The correct answer is "D." Older patients are at greater risk of developing serious intracranial injuries, and the age of 60 is usually considered an independent indication for a head CT with significant injury. While there is no "upper limit of normal" for vomiting after head trauma, the best data available suggest that any vomiting after head trauma in an adult indicates the need for a head CT. The currently recommended criteria for a CT of the head in various age groups are listed in Table 1-6.

You obtain the head CT and find a subdural hematoma. You arrange to transfer this patient for neurosurgical intervention in order to drain the subdural hematoma. It is about a 4-hour drive by ambulance to the nearest facility that has a neurosurgeon.

Question 1.7.5 Which of the following is indicated as prophylaxis against increased intracranial pressure in this patient?

A) Hyperventilation after intubation.

B) IV mannitol.

C) Trendelenburg position.

D) IV dexamethasone.

E) None of the above.

Answer 1.7.5 The correct answer is "E." None of the above is indicated as prophylaxis for increased intracranial pressure. "A" is incorrect for two reasons. First, this patient does not need to be intubated. Second, routine hyperventilation as prophylaxis for increased intracranial pressure is of no benefit. This has been well studied. What happens is that hyperventilation does cause vasoconstriction reducing intracranial blood flow and therefore intracranial pressure. However, hyperventilation also causes ischemia around the area of the injury and may worsen outcomes. "B" is incorrect because prophylactic mannitol, like prophylactic hyperventilation, confers no benefit. "C" is incorrect. Trendelenburg positioning, or elevating the legs above the heart, would result in increased intracranial pressure. There is very limited data to support or refute prophylactic elevation of the head of the bed to prevent increased intracranial pressure; while this will reduce intracranial pressure, cerebral perfusion pressure will also be mildly reduced. For treatment of increased intracranial pressure, there is slightly more evidence for benefit of elevating the head of the bed "D" is incorrect since steroids are not useful acutely in head trauma. However, steroids are useful in cerebral edema secondary to tumor.

Objectives: Did you learn to…

• Use the GCS?

• Recognize which patients with head trauma are appropriate to obtain a head CT?

• Manage patients presenting with potential intracranial injuries?

A 23-year-old male is in a bar fight. He only had "two beers" and was just standing there "minding my own business" when he was jumped by those infamous "two dudes" (how can those two dudes be in so many places at once!). He presents to you about 1 hour after the event with facial trauma. His vitals are normal and he is mentating well (with the exception of some impaired judgment secondary to the alcohol). His blood alcohol level is 150 mg/dL, showing that he is legally intoxicated. On examination, you notice that the patient has some epistaxis and a quite swollen nose. In addition, there is one avulsed tooth and one tooth that is displaced.

Question 1.8.1 The best way to transport an avulsed tooth is:

A) In sterile water.

B) In the buccal mucosa after thorough washing with soap.

C) In a glass of milk.

D) Wrapped in saline-soaked gauze.

E) Under a pillow.

Answer 1.8.1 The correct answer is "C." The best way to transport an avulsed tooth is (1) in a glass of milk, (2) in Hanks' balanced salt solution (good luck finding this when you need it!), or (3) in the buccal mucosa or under the tongue in a patient in whom the risk of aspiration is not a concern. "A" is incorrect because sterile water is hypotonic and may damage the tooth root decreasing the success rate of re-implantation. "B" is incorrect because washing the tooth with soap is not appropriate. Again, you want to maintain the viability of the root if possible. "D" is incorrect as well. If this is the only option available to you, it is better than nothing, but a glass of milk or under the buccal mucosa is preferred. "E" is acceptable only if you are a tooth fairy.

You call the dentist who is (of course) out of town. A dentist will not be available for at least 12 hours.

Question 1.8.2 Your best course of action at this point is:

A) Continue to keep the tooth viable in a glass of milk.

B) Continue to keep the tooth viable in the buccal mucosa.

C) Clean the tooth and keep it sterile and dry for re-implantation in 12 hours realizing that a bridge will probably be needed to hold the tooth in position.

D) Reinsert the tooth into the socket yourself.

Answer 1.8.2 The correct answer is "D." If there is going to be any delay in reimplantation by a dentist, the best course of action is to reinsert the tooth into the socket yourself. "A," "B," and "C" are all incorrect because they will reduce the rate of successful reimplantation.

You now turn your attention to this patient's bloody nose and are trying to decide whether or not get an x-ray.

Question 1.8.3 The BEST timing for a radiograph of the nose is:

A) As soon as possible after the trauma once other injuries are stabilized and more important problems are addressed.

B) As soon as possible to assure that there are no bone fragments threatening the brain.

C) There is no need for a radiograph acutely. You can wait for 3 or 4 days.

D) There is never any indication for nasal radiographs.

Answer 1.8.3 The correct answer is "C." There is no need for radiographs acutely except in extraordinary circumstances. The reasons for a radiograph are to document a fracture and to assist in reduction. Because of swelling, it is difficult to get a good cosmetic result reducing a nasal fracture acutely. Thus, a radiograph is indicated in 3 to 4 days only if there is evidence of nasal deformity once swelling has resolved. If there is good cosmesis and the patient can breathe through his (they are almost always male) nose, a radiograph is unnecessary just to document a fracture. "A" and "B" are incorrect because, as noted earlier, there is no reason to do a radiograph at all unless there is evidence of deformity once the swelling is resolved. "D" is incorrect for the reasons noted earlier.

Question 1.8.4 You get the epistaxis stopped and examine the nasal mucosa. Which one of these is considered an emergency?

A) Closed nasal fracture.

B) Septal hematoma.

C) Trauma to Kiesselbach plexus.

D) A deviated septum.

Answer 1.8.4 The correct answer is "B." A septal hematoma is considered an emergency. The problem is that the perichondrium, which supplies nutrition to the septum, is no longer in contact with the septum because of the intervening hematoma. Thus, the septal cartilage can necrose leading to a perforated septum. Septal hematomas should be drained acutely and the nose packed to keep the perichondrium in contact with the septal cartilage. "A" is incorrect (see previous question). "C" is incorrect. Kiesselbach plexus is in the anterior nose and is a venous plexus. Bleeding is easily controlled and generally is self-limited. "D," a deviated septum, may indicate an underlying fracture but in and of itself is not an emergency.

You continue to evaluate this patient and note that he has the loss of upward gaze in the right eye, the side on which he was hit. All of the other extraocular motions are intact.

Question 1.8.5 The most likely diagnosis in this patient is:

A) Blowout fracture with entrapment of the inferior rectus.

B) Blowout fracture with dysfunction of the superior rectus.

C) Injury to cranial nerve III, which controls the superior AND inferior rectus muscles.

D) Volitional refusal to perform upward gaze on the right side in this intoxicated patient.

Answer 1.8.5 The correct answer is "A." The most likely diagnosis is blowout fracture with entrapment of the inferior rectus. The force of a blow to the globe is transmitted to the inferior orbital wall, which is the weakest point in the orbit. This can cause entrapment of the contents of the inferior orbit, including the inferior rectus, causing an inability to perform upward gaze. Due to disconjugate gaze, patients with entrapment of the inferior rectus muscle from a blowout fracture may complain of diplopia. "B" is incorrect because a blowout fracture generally refers to the inferior orbital wall, which would not entrap the superior rectus. In addition, patients with an entrapped superior rectus would have difficulty with downward gaze. "C" is incorrect because it is unlikely that being hit in the face would cause an injury to CN III. In addition, a CN III lesion would affect all extraocular muscles except for the lateral rectus (CN VI) and the superior oblique (CN IV). "D" is incorrect because it is impossible to move the eyes independently of one another unless you are a chameleon or particularly talented.

The patient has had a long night of partying, and it is 3:00 AM Saturday morning when you call your consultant about the blowout fracture. The consultant is not happy and refuses to see the patient acutely. He wants you to send him to the office in 3 days (Tuesday morning).

Question 1.8.6 Your response is:

A) To call another consultant; a blowout fracture should be attended to immediately.

B) Do nothing; evaluation in 2 to 3 days for a blowout fracture, even with inferior rectus entrapment, is appropriate.

C) Start steroids to reduce muscle edema to facilitate the spontaneous release of the entrapped muscle.

D) Start antibiotics and hospitalize the patient so that he can be seen in the morning when the consultant makes rounds.

E) Stick pins in a voodoo doll of your consultant.

Answer 1.8.6 The correct answer is "B." While blowout fractures with muscle entrapment require close follow-up, there is no need to intervene acutely. In fact, a decision to operate may be delayed for up to 14 days. If the entrapment spontaneously resolves when the swelling goes down (not uncommon) and there is no diplopia or other complicating symptoms, surgery is not needed. The other answers are all incorrect because acute intervention is not required in this patient. "E," however, may be of some benefit… depending on your voodoo skills.

The patient mentioned above has a "friend" who was also in the altercation. He, too, was just "minding his business"—like everyone in the bar—until there was a gentleman's disagreement that could only be resolved with a broken bottle. He has a simple laceration of the chin, which you repair. This patient has a blood alcohol level of 150 mg/dL (the legal limit in most states is 80 mg/dL). Since he is intoxicated, the nurses are reluctant to allow the patient to leave because of liability issues. He seems initially very cooperative and competent. However, the nurse manager reminds you of the legal issues. The patient is getting more agitated; he wants to go home.

Question 1.8.7 Your response is:

A) Sedate the patient with haloperidol and observe him until sober.

B) Sedate the patient with a benzodiazepine and observe him until sober.

C) Call the police to remove this patient from your ED.

D) Use restraints on the patient and observe him until sober, as sedative drugs may prolong time in the ED.

E) Let the patient leave the ED with a competent adult.

Answer 1.8.7 The correct answer is "E." The patient was initially cooperative and competent. Competence is not based on a blood alcohol level but rather on your judgment of the patient's ability to make rational decisions. We allow patients on narcotics to make decisions about their own care all of the time despite having narcotics on board. There are patients who will have capacity and are safe at a blood alcohol of 200 mg/dL and others who may be impaired at 80 mg/dL. So, judge capacity individually.

Objectives: Did you learn to…

• Treat acute dental trauma?

• Diagnose and manage nasal and periorbital trauma?

• Care for the intoxicated patient with minor trauma?

A 17-year-old female fell asleep with her contact lenses in her eyes last evening. This morning she notes quite a bit of eye pain and photophobia. You evert the eyelids (something that should be done in all cases of possible foreign body) and find no evidence of a foreign body. When you stain her eye, you find a corneal ulcer.

Question 1.9.1 The treatment for this patient is:

A) Debridement with a burr and systemic antibiotics.

B) Debridement with a cotton swab and systemic antibiotics.

C) Topical antibiotics, cycloplegia, and referral to ophthalmology.

D) Copious irrigation, systemic antibiotics, and cycloplegia.

Answer 1.9.1 The correct answer is "C." This is an ophthalmologic emergency that requires topical antibiotics, cycloplegia (for pain control), and referral to an ophthalmologist. These ulcers can become quite deep and result in a ruptured globe.

You consult with your ophthalmologist who would like you start a cycloplegic agent in this patient prior to transfer.

Question 1.9.2 The drug you would choose for a cycloplegic agent is:

A) Pilocarpine eye drops.

B) Timolol eye drops (e.g., Timoptic).

C) Tetracaine eye drops.

D) Cyclopentolate eye drops.

Answer 1.9.2 The correct answer is "D." Cyclopentolate is the only cycloplegic agent listed above. Cycloplegic agents paralyze the ciliary muscle so the eye cannot accommodate. Pilocarpine is a miotic agent. Timolol is a beta-blocker used in the treatment of glaucoma. Tetracaine eye drops are a topical anesthetic. Thus, "D" is the only correct answer. Other cycloplegic agents include homoatropine and atropine. However, these have a prolonged effect.

Question 1.9.3 If your patient just had a simple corneal abrasion, you would not have had to think so hard! Regarding corneal abrasions, you realize that:

A) Patching an eye after a corneal abrasion reduces pain and promotes healing.

B) If a topical antibiotic is needed after a large corneal abrasion, gentamicin ophthalmic ointment is the drug of choice.

C) Tetracaine is a good topical anesthetic and should be considered for home use in patients with a painful corneal abrasion.

D) Patients should avoid wearing contact lenses until the eye has been healed for at least a week.

Answer 1.9.3 The correct answer is "D." "A" is incorrect because patching an eye may actually increase pain and decrease healing. Whether or not to use a patch should be a matter of patient comfort only. "B" is incorrect because gentamicin ophthalmic ointment (as well as other topical aminoglycosides) actually reduces healing of the cornea, and antibiotics are not necessary unless there are signs of infection. "C" is incorrect because patients should never be sent home with a topical anesthetic. They reduce healing and can lead to further injury if the patient, whose eyes are now insensate, continues a harmful activity, rubs his/her eyes, etc.

Objectives: Did you learn to…

• Recognize a corneal ulceration and treat it appropriately?

• Treat corneal abrasions?

• Understand the proper use of cycloplegic agents?

You are on call for your group and a welder who was welding and grinding presents at 2:00 AM with severe bilateral eye pain. When he left work at 5:00 PM the day before, he did not notice any problem. He notes that he was wearing his dark goggles some of the time while he was welding but did quite a bit of work without goggles as well.

The most likely diagnosis in this patient is:

A) Foreign body.

B) Ultraviolet (UV) keratitis.

C) Globe penetration secondary to the welding and a foreign body.

D) Iritis.

The correct answer is "B." This patient likely has UV keratitis. The others are not likely because they generally present unilaterally. In addition, in the cases of "A" and "C," they should present directly after the event rather than 9 hours later, as in our patient.

UV keratitis is found in patients who are welders or have been out in the sun for an extended period of time (at the beach, snow skiing ["snow blindness"], tanning bed, etc.). UV keratitis generally presents as severe, bilateral, eye pain about 6 to 10 hours following the activity. It is treated with cycloplegic agents and pain medication, often requiring narcotics.

Which of the following is most commonly associated with significant vascular injury?

A) Pubic ramus fracture.

B) Knee dislocation.

C) Shoulder dislocation.

D) Elbow dislocation.

E) Ankle dislocation.

The correct answer is "B." In up to 33% of knee dislocations (not patellar dislocations), a popliteal artery injury can be identified. It is debated as to whether all patients with knee dislocations require angiography or CT angiography or if physical examination and ankle-brachial indices are sufficient to rule out popliteal artery injury, but vascular injury is a major cause of limb loss and morbidity. "A" is incorrect because pubic ramus fractures are relatively minor injuries without vascular involvement, requiring only pain control. Shoulder dislocations ("C") are commonly associated with injury to the axillary nerve. Elbow dislocations ("D") can be associated with injury to the median nerve and brachial artery. However, arterial injuries are much less common than with knee dislocations. Ankle dislocations ("E") are rarely associated with vascular injury.

A 55-year-old male farmer is injured by a grass-fed cow that pins him against a fence. His leg was trapped against the fence for a several minutes. Being a typical Midwestern farmer, he ignores the injury until his wife convinces him later that afternoon to have it evaluated. He presents to your office complaining of severe pain in the calf area. A radiograph is normal, and the patient has normal distal pulses. The calf (his leg, not the cow) is tender with increased pain on passive stretch. His pain seems to be out of proportion to his injury. The calf (the cow) may also be tender and USDA grade prime.

Question 1.10.1 Which of the following is true?

A) Since the patient has excellent pulses, a compartment syndrome is not likely.

B) Compartment syndrome is defined as compartment pressure >30 mm Hg.

C) Compartment syndrome is only associated with significant crush injuries or fractures.

D) Pain out of proportion to the injury is a red flag for compartment syndrome.

Answer 1.10.1 The correct answer is "D." Pain out of proportion to the injury is a red flag for compartment syndrome. "A" is incorrect because pulses can be maintained until there is significant increase in compartment pressures and significant injury to muscle and nerves. "B" is incorrect because it is difficult to define a specific cut off for compartment syndrome. Some patients tolerate higher pressures and others cannot tolerate 30 mm Hg (normal compartment pressure is zero). However, when the pressure gets above 20 to 30 mm Hg, strong consideration should be given to the presence of compartment syndrome. "C" is incorrect. Compartment syndrome can be due to a number of factors including electrical injury, excessive muscle use, tetany, reperfusion after ischemia, aggressive volume resuscitation, etc.

You decide that it is likely that this patient has a compartment syndrome.

Question 1.10.2 Which of the following labs will be the most helpful in guiding treatment for this patient?

A) CBC.

B) Urinalysis.

C) Glucose.

D) Sodium.

E) PT/PTT.

Answer 1.10.2 The correct answer is "B." One of the major complications of compartment syndrome is rhabdomyolysis. This will manifest itself as a urine which is dipstick positive for blood but with a negative microscopic examination for red blood cells. The positive dipstick is picking up myoglobin in the urine. Rhabdomyolysis can be confirmed by a serum level of creatine phosphokinase (CPK). CBC, glucose, sodium, and coagulation studies may be appropriate depending on the clinical situation but are not useful in establishing the presence of myoglobinuria.

The patient has a positive dipstick for blood with no red blood cells on microscopic examination (presumptive myoglobinuria). His serum CPK is 32,000 U/L, which is well above five times the upper limit of normal (the cutoff for consideration of rhabdomyolysis, although levels of > 15,000 U/L are common when one has symptomatic rhabdomyolysis), so you make the diagnosis of rhabdomyolysis.

Question 1.10.3 The most common adverse consequence and greatest danger of rhabdomyolysis is:

A) Disseminated intravascular coagulation.

B) Acute kidney injury.

C) Seizure from hypocalcemia.

D) Acute gout from hyperuricemia.

E) Cardiac arrhythmia from hyperkalemia.

Answer 1.10.3 The correct answer is "B." Myoglobin precipitates in the renal tubules causing acute kidney injury. "A," DIC, can occur but is rare. "C," seizures from hypocalcemia, have not been reported in this condition, nor has "D," gout. The potassium elevation from rhabdomyolysis may reach a level sufficient to cause arrhythmias; this is exacerbated by possible coexistent hypocalcemia.

Question 1.10.4 The primary treatment for rhabdomyolysis is:

A) Mannitol infusion.

B) Saline infusion.

C) Furosemide.

D) Dialysis.

Answer 1.10.4 The correct answer is "B." The most important treatment for rhabdomyolysis is saline infusion. Lactated Ringers should be avoided as it contains potassium, which may further contribute to hyperkalemia as mentioned above. There has previously been debate if alkalinization of the urine (using IV sodium bicarbonate) has any additive benefit for preventing acute kidney injury over saline alone, but there is no evidence that supports this practice. "A," mannitol, can be used to increase urine flow, but this is really a treatment that is secondary to good hydration and may cause hypovolemia compounding the problem "C," furosemide, is controversial and has no outcome benefit but can be used for fluid overload. "D," dialysis, is what we are trying to avoid using saline.

The patient is able to maintain urine output after you institute saline.

Question 1.10.5 What treatment are you going to suggest for the underlying compartment syndrome?

A) Fasciotomy.

B) Immobilization and traction.

C) Hot packs and elevation of the affected limb.

D) Ice and elevation of the affected limb.

Answer 1.10.5 The correct answer is "A." The treatment of compartment syndrome is fasciotomy. A rapid surgical or orthopedic consultation is critical in the treatment of compartment syndrome.

The patient does well and everyone is happy… except for the cow, who finds his way onto the table as the centerpiece of Christmas dinner.

Objectives: Did you learn to…

• Recognize manifestations of compartment syndrome and understand that compartment syndrome can be present with pain alone?

• Identify patients at risk for compartment syndrome and rhabdomyolysis?

• Manage compartment syndrome?

• Diagnose and treat rhabdomyolysis?

A 24-year-old African-American male presents to the ED complaining of fever, chills, and dyspnea. He has chest pain that is respirophasic ("pleuritic") in nature. He is noted to be tachypneic with a respiratory rate of 36 and an oxygen saturation of 90%. He has a history of sickle cell disease and has had a number of sickle cell crises in the past. He is up to date on immunizations, including Streptococcus pneumoniae and Haemophilus influenzae vaccines.

Question 1.11.1 The patient's current symptoms are MOST concerning for and suggestive of:

A) Pneumothorax.

B) Pulmonary embolism.

C) Acute chest syndrome.

D) Sickle cell-related pericarditis.

E) Thoracic aortic aneurysm dissection.

Answer 1.11.1 The correct answer is "C." This patient likely has acute chest syndrome, which is associated with sickle cell anemia and may be indistinguishable from pneumonia. Acute chest syndrome is characterized by pleuritic chest pain, fever, cough, chills, dyspnea, rales, and rhonchi. The etiology is unknown, but it may be secondary to infarction of the lung and/or fat emboli. All of the other diagnoses should also be entertained at this point, but acute chest syndrome is most likely. Sickle cell-related pericarditis ("D") is a rare complication of the disease.

Question 1.11.2 All of the following are recommended in the initial treatment of acute chest syndrome EXCEPT:

A) Hydroxyurea.

B) Oxygen.