1. As you arrive for your ED shift, you are called to help with a "coding" patient. The senior resident has just intubated the patient and the nurses have established IV access and attached the cardiac monitor. An emergency medical treatment (EMT) student is performing chest compressions. You ask the EMT student to stop compressions. The monitor shows a flat line with no electrical activity. You are unable to detect any pulses. What is your next step in management?

a. Defibrillate at 360 J

b. Epinephrine 1-mg IV push

c. Atropine 1-mg IV push

d. Ask the nurse to run a rhythm strip in an additional lead

e. Apply transcutaneous pacers

The answer is D.

EXPLANATION: Asystole is absent heart rhythm or more colloquially, "flat line." A common cause of asystole is a disconnected lead or malfunctioning equipment, so the AHA recommends confirmation of asystole by switching to another lead on the cardiac monitor. Confirmation can also be achieved with a 12-lead ECG if the equipment is readily available.

Defibrillation (a) is never recommended for asystole. Transcutaneous pacing (e) failed to show benefit in several randomized controlled trials and is no longer recommended in the 2005 AHA guidelines for asystole. The appropriate treatment for asystole includes good CPR, coupled with epinephrine (b) every 3 to 5 minutes and atropine (c) every 3 to 5 minutes. A search and treatment of possible underlying etiologies is recommended.

2. A 15-year-old vegetarian being treated for tuberculosis develops peripheral neuropathy. Choose the one most appropriate vitamin or trace element—replacement therapy to treat this condition.

A. Vitamin A

B. Vitamin B₆

C. Vitamin C

D. Vitamin D

E. Vitamin E

F. Iron

G. Vitamin K

H. Folate

I. Niacin

The answer is B.

EXPLANATION: Treatment for tuberculosis usually includes the medication isoniazid (INH), and INH competitively inhibits pyridoxine utilization. In most children, this does not result in clinical manifestations, but in individuals with a poor dietary intake of pyridoxine (eg, teenagers, vegetarians, and exclusively breast-fed infants) numbness and tingling of the hands and feet may develop. Treatment is replacement of pyridoxine.

Cow's milk contains an insufficient quantity of iron to sustain normal RBC production. Therefore, children whose primary caloric source is cow's milk are likely to develop iron-deficiency anemia, characterized by microcytosis and hypochromia on the peripheral smear.

Hemorrhagic disease of the newborn is now rare, as the vast majority of newborns receive a vitamin K injection shortly after birth. Classic disease presents within the first week of life and is characterized by hematemesis, hematuria, umbilical stump and circumcision oozing, and purpura.

Vitamin C deficiency impairs wound healing. In its severe form, also termed scurvy, children can have diffuse tenderness, which is worse in the legs; evidence of hemorrhage; irritability; low-grade fever; swelling; tachypnea; and poor appetite. Diagnosis is based on clinical picture and radiographic findings; there are no definitive laboratory studies.

Vitamin A deficiency manifests first in visual changes, including night blindness. Deficiency can also cause drying of the conjunctivas and sclera. Skin is frequently dry. Poor growth and impaired cognition are also seen.

Vitamin D deficiency leads to rickets and a failure of bone mineralization. Vitamin D deficiency is usually not a problem in developed parts of the world. In addition to nutritional rickets, there are congenital forms of rickets. Despite vitamin D supplementation, these children can have permanent bony disfigurement.

3. A 48-year-old male patient suffered from a stroke. After full recovery, he follows up at your office. Which of the following medication options has been proven to lower his blood pressure and prevent recurrent stroke?

A. An ACE inhibitor

B. Hydrochlorothiazide

C. An ACE inhibitor and hydrochlorothiazide

D. A -blocker

E. A -blocker and hydrochlorothiazide

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The answer is C.

EXPLANATION: The PROGRESS study (Perindopril Protection against Recurrent Stroke Study) found that an ACE inhibitor and diuretic in combination are effective in preventing recurrent stroke.

4. A 1-day-old normal-appearing infant develops tetany and convulsions. He was born at 34 weeks' gestation with Apgar scores of 2 and 4 (at 1 and 5 minutes, respectively) to a woman whose pregnancy was complicated by diabetes mellitus and pregnancy-induced hypertension. Which of the following serum chemistry values is likely to be the explanation for his condition?

A. Serum bicarbonate level of 22 mEq/dL

B. Serum calcium of 6.2 mg/dL

C. Serum glucose of 45 mg/dL

D. Serum magnesium level of 5.0 mg/dL

E. Intracranial hemorrhage

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The answer is B.

EXPLANATION: Hypocalcemia of newborn infants can be divided into two groups: early (during the first approximately 72 hours of life) and late (after approximately 72 hours). The most common type of early neonatal hypocalcemia is the so-called idiopathic hypocalcemia.

Other causes early on include maternal illness (diabetes, toxemia, and hyperparathyroidism), neonatal respiratory distress (perinatal asphyxia) or sepsis, low birth weight because of prematurity, or hypomagnesemia. Transient or permanent hypoparathyroidism and high phosphate intake are the most common factors associated with late hypocalcemia. The bicarbonate and glucose levels in the question are normal, while the elevated magnesium level may cause sedation and apnea but not tetany and seizures. Intracranial hemorrhages are less common in an infant of this gestational age, and usually do not present with tetany.

5. An 80-year-old man is admitted to the hospital complaining of nausea, abdominal pain, distention, and diarrhea. A cautiously performed transanal contrast study reveals an apple-core configuration in the rectosigmoid area. Which of the following is the most appropriate next step in his management?

A. Colonoscopic decompression and rectal tube placement

B. Saline enemas and digital disimpaction of fecal matter from the rectum

C. Colon resection and proximal colostomy

D. Oral administration of metronidazole and checking a Clostridium difficile titer

E. Evaluation of an electrocardiogram and obtaining an angiogram to evaluate for colonic mesenteric ischemia

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The answer is C.

EXPLANATION: A markedly distended colon could have many causes in this 80-year-old man. The contrast study, however, reveals a classic apple-core lesion appropriate prior to relief of this large-bowel obstruction. After medical preparation (eg, hydration, normalization of electrolytes), this patient should undergo prompt surgical management of his mechanical obstruction; conservative management by resection and proximal colostomy would generally be preferred in this elderly patient with an obstructed, unprepared bowel.

6. A 62-year-old woman has limb discomfort and trouble getting off the toilet. She is unable to climb stairs and has noticed a rash on her face about her eyes. On examination, she is found to have weakness about the hip and shoulder girdle. Not only does she have a purplish-red discoloration of the skin about the eyes, but she also has erythematous discoloration over the finger joints and purplish nodules over the elbows and knees. Which of the following is the most likely diagnosis?

A. Systemic lupus erythematosus

B. Psoriasis

C. Myasthenia gravis

D. Dermatomyositis

E. Rheumatoid arthritis

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The answer is D.

EXPLANATION: This woman presents with proximal muscle weakness and pain and a heliotrope rash about her eyes. The term heliotrope refers to the lilac color of the periorbital rash characteristic of dermatomyositis. This rash surrounds both eyes and may extend onto the malar eminences, the eyelids, the bridge of the nose, and the forehead. It is usually associated with an erythematous rash across the knuckles and at the base of the nails and may be associated with flat-topped purplish nodules over the elbows and knees. Men with dermatomyositis are at higher than normal risk of having underlying malignancies. Psoriatic arthritis may be associated with reddish discoloration of the knuckles and muscle weakness, but the heliotrope rash would not be expected with this disorder. The age of onset for a psoriatic myopathy is also atypical. Similarly, the patient's rashes are not suggestive of lupus erythematosus, although a myopathy may occur with this connective tissue disease as well.

7. An 18-year-old college girl has an extremely sore throat and high fever. She develops a rash upon administration of ampicillin. What is the associated organism?

A. Bartonella henselae

B. Pseudomonas

C. Rubivirus

D. Human herpesvirus 6

E. Escherichia coli

F. Helicobacter pylori

G. Group B streptococci

H. Listeria monocytogenes

I. Epstein-Barr virus

J. Toxocara cati

K. Campylobacter jejuni

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The answer is I.

EXPLANATION: EBV can produce a number of clinically important syndromes, one of which is mononucleosis as described in this college-age patient with fever and sore throat. Other symptoms might include headache, profound fatigue, abdominal pain, and myalgia. Splenic enlargement is common, and contact sports are to be avoided. The rash ("ampicillin rash") is poorly understood but occurs so commonly as to be diagnostic when seen; it is self-resolving.

8. A 39-year-old man is suspected of having had a transfusion reaction during resuscitation for an upper gastrointestinal (GI) bleed. Which of the following is appropriate in the management of this patient?

A. Removal of nonessential foreign body irritants, for example, Foley catheter

B. Fluid restriction

C. 0.1 M HCl infusion

D. Steroids

E. Fluids and mannitol

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The answer is E.

EXPLANATION: Hemolytic transfusion reactions lead to hypotension and oliguria. The increased hemoglobin in the plasma will be cleared via the kidneys, which leads to hemoglobinuria. Placement of an indwelling Foley catheter with subsequent demonstration of oliguria and hemoglobinuria not only confirms the diagnosis of a hemolytic transfusion reaction but is useful in monitoring corrective therapy. Treatment begins with discontinuation of the transfusion, followed by aggressive fluid resuscitation to support the hypotensive episode and increase urine output. Inducing diuresis through aggressive fluid resuscitation and osmotic diuretics is important to clear the hemolyzed red cell membranes, which can otherwise collect in glomeruli and cause renal damage. Alkalinization of the urine (pH >7) helps prevent hemoglobin clumping and renal damage. Steroids do not have a role in the treatment of hemolytic transfusion reactions.

9. A 3-day-old infant with a single second heart sound has had progressively deepening cyanosis since birth but no respiratory distress. Chest radio-graphy demonstrates no cardiomegaly and normal pulmonary vasculature. An ECG shows an axis of 120° and right ventricular prominence. Which of the following congenital cardiac malformations is most likely responsible for the cyanosis?

A. Tetralogy of Fallot

B. Transposition of the great vessels

C. Tricuspid atresia

D. Pulmonary atresia with intact ventricular septum

E. Total anomalous pulmonary venous return below the diaphragm

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The answer is B.

EXPLANATION: Transposition of the great vessels with an intact ventricular septum presents with early cyanosis, a normal-sized heart (classic "egg on a string" radiographic pattern in one-third of cases), normal or slightly increased pulmonary vascular markings, and an ECG showing right-axis deviation and right ventricular hypertrophy. In tetra-logy of Fallot, cyanosis is often not seen in the first few days of life. Tricuspid atresia, a cause of early cyanosis, causes diminished pulmonary arterial blood flow; the pulmonary fields on x-ray demonstrate a diminution of pulmonary vascularity, and left-axis and left ventricular hypertrophy are shown by ECG. Total anomalous pulmonary venous return below the diaphragm is associated with obstruction to pulmonary venous return and a classic radiographic finding of marked, fluffy-appearing venous congestion ("snowman"). In pulmonic atresia with an intact ventricular septum, cyanosis appears early, the lung markings are normal to diminished, and the heart is large.

10. A 46-year-old woman is brought to the ED by her husband for 1 day of worsening confusion. The patient has a history of systemic lupus erythematosus (SLE) and takes chronic oral steroids. She has not been feeling well for the last few days. Her BP is 167/92 mm Hg, HR is 95 beats per minute, temperature is 100.3°F (37,7 degree C), and RR is 16 breaths per minute. On examination the patient is oriented to name and has diffuse petechiae on her torso and extremities. Laboratory results reveal hematocrit 23%, platelets 17,000/L, BUN 38 mg/dL, creatinine 1.9 mg/dL. Which of the following is the most likely diagnosis?

A. Henoch-Schönlein purpura

B. Disseminated intravascular coagulopathy

C. Von Willebrand disease

D. Idiopathic thrombocytopenic purpura

E. Thrombotic thrombocytopenic purpura (TTP)

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The answer is E.

EXPLANATION: This patient presents with four of the five symptoms classically associated with TTP. These include thrombocytopenia, hemolytic anemia, neurologic deficits, renal impairment, and fever. TTP develops with fibrin-strand deposition in small vessels that attract platelets leading to platelet thrombi and thrombocytopenia. Passing RBCs get sheared in occluded vessels resulting in microangiopathic hemolytic anemia. Renal and neurologic impairment occur as a result of the lodging of thrombi in respective circulations. Plasmapheresis decreases TTP mortality from 90% to 10%. Adjunct therapies include fresh frozen plasma infusion and steroids. It is important to realize that although patients may be severely thrombocytopenic, platelet infusion is contraindicated since it exacerbates the underlying cycle of thrombogenesis. Risk factors for TTP include pregnancy, autoimmune disorders, drugs, infection, and malignancy. Hemolytic-uremic syndrome (HUS) is a closely related entity usually seen in children. There is pronounced renal dysfunction without altered mentation.

Henoch-Schönlein purpura (HSP) (a) is a small-vessel vasculitis mostly seen in children and associated with a preceding upper respiratory illness in about 50% of patients. It is characterized by purpura, usually lower extremities, abdominal pain, and hematuria. Disseminated intravascular coagulation (DIC) (b) is a coagulopathic state triggered by major trauma, infection, malignancy, drugs, or pregnancy complications. The underlying process activates the coagulation cascade which leads to diffuse thrombosis and coagulopathy as platelets and coagulation factors are consumed. Patients with DIC have profuse GI or puncture site bleeding, markedly prolonged PT/PTT times, thrombocytopenia, and elevated fibrin split products. DIC management involves treatment of the underlying disorder and replacement of depleted coagulation cascade components. Von Willebrand disease (c) is the most common bleeding disorder and involves deficiency or defect in von Willebrand factor, which normally aids in platelet adherence and carries factor VIII in plasma. Von Willebrand disease presents clinically with GI bleeding, epistaxis, easy bruising, and prolonged bleeding. Idiopathic thrombocytopenic purpura (ITP) (d) is a disorder of antibody-mediated platelet destruction. It is acute in children, usually following a viral infection, and is chronic in adults who often require splenectomy for definitive treatment.

11. A patient has a calculated basal energy expenditure of 2000 kcal/day. What is the appropriate energy requirement for the same patient in multiple organ failure?

A. 1800 kcal/day

B. 2000 kcal/day

C. 2200 kcal/day

D. 3000 kcal/day

E. 4000 kcal/day

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The answer is D.

EXPLANATION: Basal metabolic rate is the energy required to maintain cell integrity in the resting state at a normal physiologic temperature. The basal energy expenditure decreases with advancing age and varies with sex and body size. The patient's clinical condition also impacts the basal energy expenditure. During starvation, the metabolic rate is decreased by 10%. Trauma, stress, sepsis, burns, and surgery all increase the metabolic rate. The basal energy expenditure can be multiplied by a stress factor to better approximate caloric requirements. The stress factor after a routine operation is 1.1, multiple organ failure or severe injury is 1.5, and less than 50% body surface area burns is 2.0.

12. A 60-year-old man is brought to the ED complaining of generalized crampy abdominal pain that occurs in waves. He has been vomiting intermittently over the last 6 hours. His BP is 150/75 mm Hg, HR is 90 beats per minute, temperature is 99.8°F, and his RR is 16 breaths per minute. On abdominal examination you notice an old midline scar the length of his abdomen that he states was from surgery after a gunshot wound as a teenager. The abdomen is distended with hyperactive bowel sounds and mild tenderness without rebound. An abdominal plain film confirms your diagnosis. Which of the following is the most appropriate next step in management?

A. Begin fluid resuscitation, bowel decompression with a nasogastric tube, and request a surgical consult.

B. Begin fluid resuscitation, administer broad-spectrum antibiotics, and admit the patient to the medical service.

C. Begin fluid resuscitation, give the patient stool softener, and administer a rectal enema.

D. Begin fluid resuscitation, administer broad-spectrum antibiotics, and observe the patient for 24 hours.

E. Order an abdominal ultrasound, administer antiemetics, and provide pain relief.

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The answer is A.

EXPLANATION: The patient's clinical picture is consistent with a SBO. Fluid resuscitation is important because of the inability of the distended bowel to absorb fluid and electrolytes at a normal rate. Compounded with vomiting, fluid loses can lead to hypovolemia and shock. Nasogastric suction provides enteral decompression by removing accumulated gas and fluid proximal to the obstruction. A surgical consult is necessary because definitive treatment may require taking the patient to the OR to relieve the obstruction. An old surgical adage states "Never let the sun set or rise on a bowel obstruction." Broad-spectrum antibiotics (b and d) are appropriate when surgery is planned or when there is suspicion for vascular compromise or bowel perforation.

13. You are asked to see a 78-year-old woman prior to surgical repair of a femoral neck fracture. Her medical problems include hypertension, osteoporosis, and hypothyroidism. Morphine is the only medication ordered so far. She is comfortable at rest. Her BP is 136/82, HR 88, RR 16. Her cardiac examination is normal, and her lungs are clear. What is the best recommendation to prevent postoperative venous thrombosis?

A. Postoperative low-dose ASA

B. Postoperative SCDs (sequential compression devices)

C. Early mobilization and ambulation

D. Postoperative subcutaneous low-molecular-weight heparin

E. Postoperative intravenous unfractionated heparin

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The answer is D.

EXPLANATION: After orthopedic injury, patients are at high risk of development of deep vein thrombosis. Other risk factors for DVT formation include advanced age, immobility, malignancy, hypercoagulable states, and prior history of DVT. Appropriate options for DVT prophylaxis after hip fracture include subcutaneous unfractionated or low-molecular-weight heparin. SCDs (answer b) may be used in addition to chemoprophylaxis, but SCDs by themselves are not effective in hip fracture patients. Early ambulation is recommended as tolerated for all patients at risk for DVT, but is not enough to fully attenuate risk after a hip fracture. Aspirin (answer a) is never recommended by itself for inpatient DVT prophylaxis. Intravenous heparin is used for DVT therapy, not prophylaxis.

14. A 16-year-old woman comes to your office complaining of unpredictable menstrual periods. She began her periods at age 14, and they have never been predictable. She denies sexual activity in her lifetime, has no systemic illness, uses no medications regularly, and her physical examination is normal. Which of the following is her most likely diagnosis?

A. Pregnancy

B. Ovulatory bleeding

C. Anovulatory bleeding

D. Uterine leiomyoma

E. Endometrial polyposis

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The answer is C.

EXPLANATION: Anovulatory bleeding is caused by continuous unopposed endometrial estrogen stimulation. Since these patients do not ovulate, progesterone from the corpus luteum is not secreted, the withdrawal from which would normally cause endometrial sloughing. It is the most common cause of dysfunctional uterine bleeding in women younger than 20 years of age, accounting for about 95% of cases. When women are within 2 years of menarche, this is especially common, and can be followed expectantly. Alternatively, oral contraceptives can be used to regulate periods. Pregnancy should be ruled out, even in women who deny sexual activity. Ovulatory bleeding due to fluctuations in estrogen and progesterone levels is also a cause of abnormal bleeding, but accounts for only about 10% of cases. Leiomyomas and polyps may cause bleeding, but usually not in this age group.

15. A 23-year-old woman is brought to the emergency room from a halfway house, where she apparently swallowed a handful of pills. The patient complains of shortness of breath and tinnitus, but refuses to identify the pills she ingested. Pertinent laboratory values are as follows:

Arterial blood gases: pH 7.45, PCO₂ 12 mm Hg, PO₂ 126 mm Hg.

Serum electrolytes (mEq/L): Na⁺ 138, K⁺ 4.8, Cl^– 102, HCO₃^– 8.

An overdose of which of the following drugs would be most likely to cause the acid–base disturbance in this patient?

A.Phenformin

B. Aspirin

C. Barbiturates

D. Methanol.

E. Valium (Diazepam)

The answer is B.

EXPLANATION: This patient's history of tinnitus in conjunction with her mixed metabolic acidosis-respiratory alkalosis is pathognomonic of salicylate intoxication. Salicylates directly stimulate the respiratory center and produce respiratory alkalosis. By building up an accumulation of organic acids, salicylates also produce a concomitant metabolic acidosis. The patient is in a state of metabolic acidosis as shown by a markedly increased anion gap of 28 mEq unmeasured anions per liter of plasma. However, the respiratory response is greater than can be explained by a compensatory response; respiratory compensation alone would not result in an alkalemic pH. The disturbance cannot be pure respiratory alkalosis, since the serum bicarbonate does not drop below 15 mEq/L as a result of renal compensation and the anion gap does not vary by more than 1 to 2 mEq/L from its normal value of 12 in response to a respiratory disturbance. The renal response to hyper-ventilation involves wasting of bicarbonate and compensatory retention of chloride; it does not involve a change in the concentration of unmeasured anions, such as albumin and organic acids.

Phenformin and methanol overdoses also produce high-anion-gap metabolic acidosis, but without the simultaneous respiratory disturbance. Sedatives, such as barbiturates or diazepam, would result in hypoventilation with respiratory acidosis.

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