🇨🇦 MCCQE1,2 | #Case_241 | #answer
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

✅ A

🔎 Explanation

ACE inhibitors can significantly worsen renal failure in patients with hypertension caused by renovascular disease. Hyperkalemia is an associated problem. Captopril renography is a useful diagnostic screening test.The other agents are useful for lowering blood pressure but may cause mild creatinine elevations. They do not, however, cause the significant elevations of creatinine seen with ACE inhibitors in cases of significant renovascular disease

🇨🇦 MCCQE1,2 | #Case_242
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

A 74-year-old black female has moderately severe pain due to osteoarthritis. However, she is also on medication for a seizure disorder. When choosing medications to manage her chronic pain, which one of the following should be used with caution because of her history of seizures?

a) Salsalate (Disalcid)
b) Celecoxib (Celebrex)
c) Hydrocodone (Lortab)
d) Oxycodone (OxyContin)
e) Tramadol (Ultram)

🇨🇦 MCCQE1,2 | #Case_242 | #answer
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

✅ E

🔎 Explanation

According to the clinical practice guidelines for management of persistent pain in older persons, tramadol has efficacy and safety similar to those of equianalgesic doses of codeine and hydrocodone. However, because of the threat of seizures (rare but potential), tramadol should be used with caution in patients with a history of seizure disorder or those taking other medications that lower seizure thresholds.

🇨🇦 MCCQE1,2 | #Case_243
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

A 15-month-old male is brought to the emergency department following a generalized tonic-clonic seizure at home. The parents report that the seizure lasted 5 minutes, with confusion for the next 15 minutes. This is the child’s first seizure. There is no family history of seizures. His medical history is normal except for a 1-day history of a URI. While initially lethargic in the emergency department, the child is now awake and playful, with a temperature of 39.5°C (103.2°F) and a normal examination. Appropriate diagnostic tests are performed, including a blood glucose level, which is 5.3 mmol/L (96 mg/dL). Which one of the following would be most appropriate to administer at this point?

a) Phenytoin (Dilantin) intravenously
b) Ceftriaxone (Rocephin) intravenously
c) Acetaminophen orally
d) Carbamazepine (Tegretol) orally
e) Phenobarbital orally

🇨🇦 MCCQE1,2 | #Case_243 | #answer
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

✅ C

🔎 Explanation

This child has had a simple febrile seizure, the most common seizure disorder of childhood. Treatment includes finding a source for the fever; this should include a lumbar puncture if meningitis is suspected. The most common infections associated with febrile seizures include viral upper respiratory infections, otitis media, and roseola. Antipyretics are the
first-line treatment. Antibiotics are indicated only for appropriate treatment of underlying infections. Phenytoin and carbamazepine are ineffective for febrile seizures. Phenobarbital is sometimes used for prevention of recurrent febrile seizures, but is not indicated as an initial therapy. Only 30%-50% of children with an initial febrile seizure will have recurrent seizures.

🇨🇦 MCCQE1,2 | #Case_244
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

A 72-year-old woman with a history of COPD and arthritis presents to the ED with difficulty breathing. Her caregiver tells you she is “feverish”, breathing harder than normal and coughing up much more sputum which has turned thick and green. Your management plan should consist of:

a) ABC’s, supplemental O2 and bronchodilation
b) ABC’s, BiPAP
c) ABC’s, O2, bronchodilators, systemic steroids, antibiotics
d) ABC’s, systemic steroids and antibiotics
e) Immediate intubation and admission to the ICU

🇨🇦 MCCQE1,2 | #Case_244 | #answer
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

✅ C

🔎 Explanation

A COPD exacerbation can be triggered by a range of factors such as viral/bacterial infections, environmental irritants, CHF & PE. Exacerbations are indicated by an increase in coughing and sputum production/volume from baseline, sputum purulence; wheezing, chest tightness and fevers may also present. Investigations should include: CBC, Serum chemistries, ABG (if severe), ECG, CXR, Blood/Sputum cultures. Management should consist of:

1. An assessment of ABC’s;
2. Supplemental O2;
3. Bronchodilators by nebulizer (e.g. salbutamol, ipatropium);
4. Systemic corticosteroids (e.g. IV solumedrol);
5. Antibiotics (if indicated: i.e., purulent sputum, elevated WBC’s, fevers...etc) e.g. doxycycline, trimethoprim-sulfamethoxazole and amoxicillin clavulanate to cover the usual suspects (Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis).

⚠ BiPaP (b) is reserved for severe exacerbations.

⚠ Option (e) is indicated in patients with deteriorating arterial blood gas (ABG) values, altered mental status (AMS) and progressive respiratory fatigue.

🔖 PEARL: Management of COPD exacerbation should include: ABC’s, O2, bronchodilators, systemic steroids, and antibiotics

🇨🇦 MCCQE1,2 | #Case_245
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

A 58-year-old man with type 2 diabetes mellitus, diagnosed 3 years ago, has come in for his annual check-up. He also has a history of hypertension and hyperlipidemia. He is on metformin 1000 mg twice a day. He is compliant with his medications but has a sedentary life style (body mass index = 31). His blood biochemistry is remarkable for glycated hemoglobin of 7.5%. You recommend addition of a second oral hypoglycemic agent. Which of the following hypoglycemic agents that acts on both alpha and beta cells of pancreas would be a suitable addition to his current management?

a) Glimepiride
b) Sitagliptin
c) Pioglitazone
d) Acarbose
e) Repaglinide

🇨🇦 MCCQE1,2 | #Case_245 | #answer
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

✅ B

🔎 Explanation

Sitagliptin (choice B) is a dipeptidyl peptidase-4 (DPP-4) inhibitor that prevents breakdown of glucagon-like peptide-1 (GLP-1) and increases its level. GLP-1 is an incretin hormone with multiple physiologic effects. It stimulates the release of insulin from beta-cells and decreases glucagon secretion from alpha-cells in a glucose-dependent manner, resulting in a decrease in blood glucose levels. There is minimal risk of hypoglycemia with DPP-4 use. Two classes of antihyperglycemic agents increase the concentration of GLP-1: DPP-4 inhibitors and GLP-1 receptor agonists.
Sitagliptin is not associated with weight gain which is an advantage in this case since the patient is obese.

⚠ Glimepiride (choice A), a sulfonylurea, lowers blood glucose level by stimulating the release of insulin from pancreatic beta-cells. It binds ATP sensitive potassium channel receptors, which causes membrane depolarization, increase in intracellular calcium, and secretion of insulin. The insulin release is not glucose dependant. It has no effect on alpha cells or glucagon release.

⚠ Repaglinide (choice E) acts by stimulating release of insulin from pancreatic beta-cells. It acts on a different binding site than the sulfonylurea. Repaglinide increases the amount of insulin released in a natural and physiological pulsatile pattern. It has shorter duration of action and is used for pre-prandial administration. It does not act on alpha cells.

⚠ Acarbose (choice D), an alpha-glucosidase inhibitor, delays the intestinal hydrolysis of oligo- and disaccharides. Consequently, the absorption of monosaccharides after a meal is delayed. It is used for control of prandial hyperglycemia. It does not act on pancreatic alpha or beta cells.

⚠ Pioglitazone (choice C) improves glycemic control by improving insulin sensitivity through its action on peroxisome proliferator-activated receptor (PPAR) gamma, and affects lipid metabolism through action on PPAR alpha. Together, these can increase glucose uptake and utilisation in the peripheral organs, decrease gluconeogenesis in the liver, thereby reducing insulin resistance and improve lipid profile. It has no action on pancreatic alpha or beta cells.


🔖Key point:

Incretin mimetics, such as Exenatide, act on both alpha and beta cells of pancreas in glucose dependant manner and are associated with minimal risk of hypoglycaemia

🇨🇦 MCCQE1,2 | #Case_246
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

A 32-year-old male presents to your family practice clinic with a 6 month history of painless bright red blood per rectum. He notices bright red blood upon wiping as well as occasionally mixed with his stool. He has no constitutional symptoms. He is otherwise healthy with no significant medical history. There is no family history of gastrointestinal tract disease. His vitals are: BP: 110/70 mmHg, HR 98 beats per minute, RR 16 breaths per minute. He looks well. Precordial examination is normal. Abdominal exam reveals a soft abdomen. Inspection of the perianal area does not suggest external hemorrhoids. Digital rectal examination reveals no blood on digit, pain, or masses. What is your next step in your immediate management of this patient?

a) Reassure the patient that the cause is likely benign and arrange a follow-up in 4 weeks.
b) Perform an anoscopy and arrange a colonoscopy if clinically warranted.
c) Call your local gastroenterologist's office to arrange an urgent consultation and colonoscopy
d) Advise the patient to go to the nearest emergency department for treatment
e) Send for an urgent CBC

🇨🇦 MCCQE1,2 | #Case_246 | #answer
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

✅ B

🔎 Explanation

The most common cause of minimal bright red blood per rectum in those under 50 years of age with no risk factors for GI cancer is anorectal pathology (hemorrhoids, fistulas, polyps, proctitis, rectal ulcers, and GI cancers). A thorough history including documentation of risk factors for GI cancer such as a family history or irritable bowel disease must be obtained. A physical examination must then be performed to rule out anorectal pathology. This can include an office anoscopy (choice B), which will detect the presence of polyps or obstructing rectal cancer. If an immediate cause is identified for the bleeding in a patient under 50 years of age, a colonscopy may not be indicated. However, a patient with bright red blood perrectum over 50 years of age should have an outpatient colonoscopy as the risk of malignancy in this age group increases markedly. Finally, a laboratory test to rule out anemia may be indicated depending on the length of bleeding and/or presence of anemic symptoms such as fatigue, dizziness or shortness of breath.

⚠ While the most probable cause is likely benign, a simple reassurance with follow-up (choice A) is not advised in case serious pathology is the actual cause.

⚠ While referral to colonoscopy is a reasonable course of action, a call for urgent colonoscopy (choice C) is not warranted particularly with a low pre-test probability for serious pathology given the patient's age, symptoms, and family history.

⚠ Advising the patient to go to the nearest ED (chice D) would be the correct course of action if you were concerned about an acute lower GI bleed that usually presents with brisk or constant bleeding.

⚠ While a CBC (choice E) is a reasonable lab test to order, it is not the immediate next step in managing this patient.

🔖 Key point:

Prolonged minimal bright red blood per rectum is a common complaint in those under 50 years old. A full history and
physical, including office anoscopy should be performed. However, any patient over 50 years of age with prolonged bright red blood per rectum should be referred for an outpatient colonoscopy

🇨🇦 MCCQE1,2 | #Case_247
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

A 4-year-old boy was brought to hospital with fever for the last 6 days. The boy looked ill but not pale or jaundiced and his body temperature was 38.6°C. Examination of the mouth showed generalized erythema of oropharynx, strawberry tongue and red fissured lips. Polymorphous, confluent maculo-papular erythematous skin rash was noted. Two enlarged cervical lymph nodes could be palpated. Laboratory examination showed mild anemia and raised ESR. Kawasaki disease was strongly suspected. Although, scarlet fever and toxic shock syndrome should be considered in the differential diagnosis of this presentation, they are less likely because of:

a) The type of the rash
b) Fissuring of the lips
c) The mild anemia
d) The ill look of the patient
e) The raised ESR

🇨🇦 MCCQE1,2 | #Case_247 | #answer
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

✅ B

🔎 Explanation

Fissuring of the lips is a strong clue for differentiating Kawasaki disease from scarlet fever and toxic shock syndrome.

⚠ Scarlet fever and toxic shock syndrome might have the same type of scarlatiniform rash as Kawasaki disease described in this case.

⚠ Mild anemia, the ill look and high ESR might all accompany severe scarlet fever and toxic shock syndrome. Careful physical examination (fissuring of the lips in this case) is a strong tool in differentiating between diseases with similar presentations

🇨🇦 MCCQE1,2 | #Case_248
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

A 32-year-old woman comes to the emergency department complaining of fever, nausea, and vomiting for the past week. She has already vomited three times in the morning at home and one more time in the hospital. She also has some tenderness the pelvic region. Her last menstrual period was six weeks ago. She states that she has had many sexual partners in the past year. Past medical history includes an infection in the genital area that was treated with antibiotics two years ago. Vital signs indicate a temperature of 39°C, heart rate of 82 bpm, blood pressure of 92/59 mmHg, and respiratory rate of 24 bpm. Physical examination of the abdomen and pelvic area shows rebound tenderness. Ultrasound shows abscess in the pelvic region. What is next best step in management of this patient?

a) Admit and give IV cefoxitin and doxycycline
b) Admit and give IM ceftriaxone and PO doxycycline
c) Discharge the patient and advise to follow-up in one week
d) Discharge the patient and prescribe IM cefoxitin and PO doxycycline
e) Prepare for laparoscopy

🇨🇦 MCCQE1,2 | #Case_248 | #answer
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

✅ E

🔎 Explanation

Pelvic inflammatory disease(PID) presents with infection and inflammation of the upper genital tract in women including the uterus, fallopian tubes, and/or ovaries. Risk factors for PID are the same as those for acquiring sexually transmitted infections: multiple sexual partners, young age, smoking, and illicit drug use. Neisseria gonorrhoeae and Chlamydia trachomatis are pathogens most commonly associated with PID though other pathogens including vaginal anaerobes may account for up to 23% in women. Criteria for diagnosis include cervical motion, uterine, or adnexal tenderness along with fever, vaginal/cervical discharge, leukocytosis, positive cultures and elevated C-reactive protein. Salpingitis and endometritis are also associated with PID and severe cases increase risk of ectopic pregnancy and infertility. Patients suspected of PID that are pregnant, non-responsive to oral antibiotic therapy for 72 hours, non-compliant to outpatient management, severe fever/nausea/vomiting and have tubo-ovarian abscess should be admitted for further evaluation and treatment. Commonly used inpatient therapeutic agents include IV 3rd generation cephalosporin and doxycycline followed by PO doxycycline for a total of 14 days. Outpatient therapy includes single dose IM ceftriaxone/cefoxitin and PO doxycycline for 14 days. This patient shows symptoms of acute PID and possible acute abdomen/sepsis therefore should be prepared for emergent surgery (choice E). Patients with tubo-ovarian abscess (TOA) larger than 10 cm should consider surgery. Surgical exploration is indicated in any patient with symptoms of acute abdomen (e.g. rebound tenderness, fever) and signs of sepsis (e.g. hypotension, tachypnea) shown in this patient.

⚠ Admit and give IV cefoxitin and doxycycline (choice A) is not correct. The patient should normally be admitted and given IV antimicrobials if the patient has severe symptoms and non-compliant or unresponsive to outpatient therapy. However, if the patient shows severe symptoms along with signs of sepsis, acute abdomen or ovarian rupture, she should undergo surgery right away.

⚠ Admit and give IM ceftriaxone and PO doxycycline (choice B) is not correct. IM ceftriaxone and PO doxycycline is commonly prescribed as outpatient therapy for PID patients.

⚠ Discharge the patient and advise follow-up in one week (choice C) is not correct. Since the patient presents with severe symptoms, she should not be discharged.

⚠ Discharge the patient and prescribe IM cefoxitin and PO doxycycline (choice D) is not correct. Since the patient presents with severe symptoms, she should not be discharged. Also, the antibiotics listed are typically used for outpatient therapy.

🔖 Key point:

Pelvic inflammatory disease presents with infection (commonly gonococcal and chlamydial) and inflammation of the upper genital tract in women including the uterus, fallopian tubes, and/or ovaries associated with salpingitis and endometritis. If the patient presents with symptoms of sepsis, acute abdomen or tubal ovarian rupture, surgical intervention is warranted

🇨🇦 MCCQE1,2 | #Case_249
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

A 19-year-old male presents to your department because of abdominal pain for the last 2 days. The pain is localized in the right lower quadrant and he rates it as 7 out of 10. He also complains of diarrhea and loss of appetite. His past medical history is non-remarkable. His family history is significant for a father with hemochromatosis. On physical examination, the patient’s skin appears bronzing, he has tenderness on palpation of the right lower
quadrant and rebound tenderness is also noted. The Rovsing sign and psoas sign are negative. Abdominal CT scan demonstrates enlarged mesenteric lymph nodes, ileocecal wall thickening, and a normal appearing appendix. What is the most likely diagnosis?

a) Yersiniosis
b) Epiploic appendagitis
c) Appendicitis
d) Ulcerative colitis
e) E coli mesenteric lymphadenitis

🇨🇦 MCCQE1,2 | #Case_249 | #answer
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

✅ A

🔎 Explanation

This patient has right lower quadrant abdominal pain, diarrhea, and anorexia. His skin appears bronzing and given his family history of hemochromatosis, he is likely to also have this disease. The above symptoms and physical examination findings when combined with the findings on CT scan that shows enlarged mesenteric lymph nodes, ileocecal wall thickening, and a normal appearing appendix suggest mesenteric lympadenitis. This is an inflammation of the mesenteric lymph nodes that may be acute or chronic depending on etiology. While E coli and other infectious agents could cause mesenteric lymphadenitis, in this patient with hemochromatosis, Yersiniosis (choice A) caused by Yersinia enterocolitica is the most likely etiology. It is an iron loving, non-lactose fermenting, and oxidase-negative facultative anaerobe. Iron overload that is characteristic of hemochromatosis patients is considered a thriving environment for these bacteria.

⚠ Epiploic appendagitis (choice B) is a rare disease that results from torsion of the epiploic appendages, which presents as an acute clinical condition mimicking diverticulitis, appendicitis, or other more serious causes of acute abdominal pain. This patient’s CT scan findings are more consistent with mesenteric lymphadenitis. In epiploic appendagitis, the most common finding on CT is a fat-density oval lesion with surrounding inflammation on the anterior aspect of the sigmoid colon.

⚠ Appendicitis (choice C) is incorrect. While this patient’s symptoms of right lower quadrant abdominal pain and the findings of rebound tenderness when the right lower quadrant is palpated are also seen in appendicitis, the negative Rovsing sign, psoas sign, and the CT scan findings point to a diagnosis of mesenteric lymphadenitis.

⚠ Ulcerative colitis (choice D) is a chronic inflammatory bowel disease that would most likely present with rectal bleeding. CT scan has limited role in the diagnosis of uncomplicated ulcerative colitis but would be useful in the diagnosis of its complications such as toxic megacolon. This patient’s CT findings point to mesenteric lymphadenitis.

⚠ E coli mesenteric lymphadenitis (choice E) is incorrect. While this patient’s clinical picture certainly fits the diagnosis of mesenteric lymphadenitis, given his hemochromatosis family history and the bronzing skin, Yersinia enterocolitica, is the more likely causative agent, as it is a well known iron-loving bacteria.


🔖 Key point:

Right lower quadrant abdominal pain, tenderness on palpation, and CT scan findings of enlarged mesenteric lymph nodes, ileocecal wall thickening, and a normal appearing appendix suggest mesenteric lymphadenitis. In a patient with hemochromatosis, Yersinia enterocolitica is the most causative agent of mesenteric lymphadenitis.

🇨🇦 MCCQE1,2 | #Case_250
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

A 17-year-old female is brought to your department by her parents. They found her laying down at home with an acetaminophen bottle next to her. When they asked her what happened she said that she had found out her boyfriend cheated on her with one of her friends. She ingested 25 oral tablets (325mg) that were in the bottle they had recently
bought. Assuming the toxicity follows the established stages after this drug ingestion, which of the following findings is least likely to be present in this patient?

a) Increased prothrombin time
b) Increased serum aspartate aminotransferase
c) Increased serum glucose
d) Increased bilirubin
e) Increased creatinine

🇨🇦 MCCQE1,2 | #Case_250 | #answer
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

✅ C

🔎 Explanation

This patient presents after an intentional overdose of acetaminophen. 150 mg/kg or 7.5 g of acetaminophen in adults are considered toxic. This patient has ingested more than 8g. In North America acetaminophen has replaced viral hepatitis as the most common cause of acute hepatic failure and is the second most common cause of liver failure requiring transplantation. Acetaminophen is metabolized in the liver via glucuronidation, sulfation, and through the cytochrome P-450 pathway. In acute overdose, acetaminophen is oxidatively metabolized to the hepatotoxic reactive metabolite, N-acetyl-p-benzoquinoneimine (NAPQI).

The clinical course of acetaminophen toxicity generally is divided into 4 stages:

- The first stage that lasts up to 24 hours may be asymptomatic but is usually characterized by anorexia, nausea, vomiting, diaphoresis, pallor, and fatigue.

- The second stage follows and goes up to 72 hours post-ingestion. It is characterized by right upper quadrant abdominal pain and tenderness, nausea and vomiting intensify, tachycardia and hypotension are noted. Elevated liver enzymes are found in labs and oliguria with elevated BUN and creatinine may occur.

- The third stage also known as hepatic stage is characterized by continued abdominal pain, development of jaundice, coagulopathy, encephalopathy and hypoglycemia.

- In patients who survive the fourth stage consists of recovery, which may take up to 21 days. Based on above, the least likely finding is increased serum glucose (choice C) because liver failure results in impaired gluconeogenesis. Hypoglycemia is expected to occur in acetaminophen toxicity.

⚠ Increased prothrombin time (choice A), Increased serum aspartate aminotransferase (choice B), Increased bilirubin (choice D) are noticed in the hepatic stage and last for several days before they normalize.

⚠ Increased creatinine (choice E) begins with stage 2 and levels greater than 300 µmol/L (3.4 mg/dL), INR of 6.5 and pH < 7.30 should prompt liver transplantation consultation.

🔖 Key point:

Common findings in acetaminophen toxicity are elevated liver enzymes, elevated prothrombin time, elevated bilirubin, elevated BUN and creatinine, and decreased serum glucose

🇨🇦 MCCQE1,2 | #Case_251
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

A 25-year-old multiparous patient at 28 weeks’ gestation has condyloma lata. Six hours after receiving her first intramuscular dose of penicillin G benzathine, 2.4 mIU, she experiences fever, chills, malaise, headache, and myalgia. She also states that her lesions have become acutely painful. Her temperature is 38.3˚C (100.9˚F), pulse is 110 bpm, blood pressure in 90/60 mm Hg, and respirations are 24/min. The most likely diagnosis is:

a) Waterhouse-Friderichsen syndrome
b) Allergic reaction to penicillin
c) Jarisch-Herxheimer reaction
d) Secondary bacteremia
e) Disseminated HPV viremia

🇨🇦 MCCQE1,2 | #Case_251 | #answer
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

✅ C

🔎 Explanation

The Jarisch-Herxheimer reaction resembles bacterial sepsis and can occur after initiation antibacterials such as penicillin or tetracycline, or treatment of tick-borne relapsing fever. This is the transient febrile reaction that occurs within the first few hours and peaks at 6-8 hours. The Jarisch-Herxheimer reaction follows a self-limited course. The Jarisch-Herxheimer reaction is often associated with fever, myalgia, headache, chills, tachycardia, increased respiratory rate, hemodynamic instability, exacerbation of skin lesions, and malaise. The circulating neutrophil count is elevated.

⚠ This is seen in meningococcemia.

⚠ Allergic reactions do not appear 6 hours after administration of the medication.

⚠ Secondary bacteremia will not make the lesions painful. Chills, malaise, and fever can be seen with bacteremia.

⚠ Condyloma lata is one of the lesions of secondary syphilis, not human papillomavirus