🇨🇦 MCCQE1,2 | #Case_208
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A 72-year-old male presents to your department with complaints of prolonged constipation, early satiety, and gastroesophageal reflux. This has led to feeling bloated most of the time and weight loss. The patient was diagnosed with Parkinson’s disease 5 years ago and is treated with Selegiiline and Levodopa-Carbidopa combination. He was recently evaluated by his neurologist and found to be in stage 4 of the Hoehn and Yahr scale of this disease. Which of the following medication is contraindicated in this patient?

a) Ropinirole
b) Metoclopramide
c) Pramipexole
d) Domperidone
e) Isradipine

🇨🇦 MCCQE1,2 | #Case_208 | #answer
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✅ B

🔎 Explanation

This patient presents with constipation and symptoms suggestive of gastroparesis or delayed gastric emptying. Gastrointestinal motility is reduced in Parkinson’s disease; besides, the medications used to treat this condition can also cause constipation. Patients can have hard, dry stools that are painful to pass due to slowed motility, and delayed emptying of a full bowel due to incoordination of rectal muscles. This could lead to complications such as paralytic ileus, acute bowel obstruction secondary to impaction, volvulus, and Ogilvie’s syndrome. Generally, metoclopramide (choice B) can be used to treat gastroparesis but it is contraindicated in patients with severe Parkinson’s disease such as this patient who was recently evaluated to be in stage 4 on the Hoehn and Yahr scale of this condition. Parkinson’s disease is characterized by loss of pigmented dopaminergic neurons and since this medication is a dopamine antagonist that crosses the brain blood barrier, it would worsen the patient’s condition.

⚠ Ropinirole (choice A) and Pramipexole (choice C) are non-ergoline dopamine agonists and they are used in the treatment of Parkinson’s disease. They are not contraindicated in this patient.

⚠ Domperidone (choice D) is a peripheral dopamine (D2) and (D3) receptor antagonist. Since it doesn’t cross the brain blood barrier like Metoclopramide, it is one of the few dopamine antagonists that can be used as prokinetic to increase gastrointestinal peristalsis and promote gastric emptying in this patient.

⚠ Isradipine (choice E) is a calcium channel blocker used as an antihypertensive medication that has been recently studied for use in treating Parkinson’s disease with promising initial results. It is not contraindicated in this patient.

🔖Key point:

Metoclopramide is a dopamine antagonist and should not be used in patients with severe Parkinson's disease.

🇨🇦 MCCQE1,2 | #Case_209
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A full-term newborn, born 72 hours ago, is noted to be jaundiced. The pregnancy was uneventful and the delivery
uncomplicated. The mother has type A-positive blood and the child has type O-positive. The child is breastfed and has lost 9 ounces from a birth weight of 8 lb. He is feeding for 20 minutes every 4 hours, and except for being icteric, has a normal examination. Laboratory evaluation reveals a total serum bilirubin level of 16 mg/dL (N 1.4-8.7), with a conjugated bilirubin level of 1.0 mg/dL. His hemoglobin level is 17.8 g/dL (N 13.4-19.8), his hematocrit is 55% (N 41-65), and his reticulocyte count is 3% (N 3-7). Appropriate management would include:

a) Phototherapy
b) Exchange transfer
c) Blood cultures and antibiotic therapy
d) Dextrose and water supplementation
e) A recommendation to increase feedings to 10 times a day

🇨🇦 MCCQE1,2 | #Case_209 | #answer
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✅ E

🔎 Explanation

Hyperbilirubinemia can occur in up to 60% of term newborns during the first week of life. Early guidelines on
management of elevated bilirubin were based on studies of bilirubin toxicity in infants who had hemolytic disease. Current recommendations now support the use of less intensive therapy in term newborns with jaundice who are otherwise healthy. Phototherapy should be initiated when the bilirubin level is above 15 mg/dL for infants at age 29-48 hours old, at 18 mg/dL for infants 49-72, and at 20 mg/dL in infants older than 72 hours. Generally, this problem is not considered pathologic unless it presents during the first hours after birth and the total serum bilirubin rises by more than 5 mg/dL/day or is higher than 17 mg/dL, or if the infant has signs or symptoms suggestive of a serious underlying illness such as sepsis. Fortunately, very few term newborns with jaundice have serious underlying pathology. Physiologic jaundice follows a pattern, with the bilirubin level peaking on the third or fourth day of life and then declining over the first week after birth. Infants with multiple risk factors may develop an exaggerated form of physiologic jaundice, with the total bilirubin level rising as high as 17 mg/dL. Breastfed infants are at an increased risk for exaggerated physiologic jaundice because of relative caloric deprivation in the first few days of life. Compared with formula-fed infants, those who are breastfed are six times more likely to experience moderate jaundice, with the bilirubin rising above 12 mg/dL. For breastfed newborns who have an early onset of hyperbilirubinemia, the frequency of feeding should be increased to more than 10 times per day. If the newborn has a decrease in weight gain, delayed stooling, and continued poor intake, then formula supplementation may be necessary. Breastfeeding should be continued to maintain breast milk production. Supplemental water or dextrose and water should not be given, as this can decrease breast milk production and may place the infant at risk for iatrogenic hyponatremia

🇨🇦 MCCQE1,2 | #Case_210
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An 83-year-old male has a long history of COPD. His resting oxygen saturation is 86% on room air. Treatment includes
oral bronchodilators, inhaled corticosteroids, inhaled beta-agonists, inhaled anticholinergics, and home oxygen. Which one of his treatments has been shown to prolong survival in cases such as this?

a) Oral bronchodilators
b) Inhaled corticosteroids
c) Inhaled beta-agonists
d) Inhaled anticholinergics
e) Home oxygen

🇨🇦 MCCQE1,2 | #Case_210 | #answer
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✅ E

🔎 Explanation

Treatment of hypoxemia is critical in the management of COPD and trials have shown a reduction in mortality with the use of oxygen for 15 or more hours daily.

⚠ Inhaled beta-adrenergic agonists and anticholinergic agents, either alone or in combination, provide symptomatic relief but do not prolong survival.

⚠ Theophylline can be used for symptoms inadequately relieved by bronchodilators.

⚠ Inhaled corticosteroids do not appear to alter the rate of decline in lung function in COPD. However, some evidence shows that these agents alleviate symptoms and reduce disease exacerbation. Pulmonary rehabilitation improves quality of life and reduces hospitalizations.

🇨🇦 MCCQE1,2 | #Case_211
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A 68-year-old man with a history of diabetes, hypertension and atrial fibrillation is admitted to the ER for severe abdominal pain. He has vomited twice in the last hour and has had one bloody stool. The patient is complaining of severe pain but your exam reveals a soft abdomen. His vitals are: HR:140 bpm, BP:85/60 mmHg, RR:19 rpm, T:38.9°C. An abdominal x-ray shows pneumatosis intestinalis (air in the bowel wall). Which of the following would be your next best step?

a) Colonoscopy
b) Complete blood count stat
c) Barium enema
d) Watchful waiting
e) Exploratory laparotomy

🇨🇦 MCCQE1,2 | #Case_211 | #answer
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✅ E

🔎 Explanation

With this patient’s history of pain out of proportion to physical findings, vomiting, bloody stool, unstable vitals and pneumatosis intestinalis on x-ray you should be highly suspicious of acute mesenteric ischemia (AMI). It is very likely that the source of the AMI was an arterial embolus most likely as a result of the patient’s atrial fibrillation (>75% of emboli originate in the heart). AMI risk factors include: atrial fibrillation, recent MI, valvular heart disease and recent vascular catheterization. The most common anatomic sites for ischemia are “Sudeck’s point” at the sigmoid flexure and “Griffith’s point” at the transverse-descending colon flexure. Immediate surgery is the gold standard for diagnosis but CT, mesenteric angiography, abdominal radiography and ECG are useful for diagnosis.

⚠ Colonoscopy, is not useful for suspected cases of AMI.

⚠ No laboratory test sufficiently rules in or rules out the diagnosis of mesenteric ischemia. Laboratory findings in mesenteric ischemia are nonspecific and generally unreliable.

⚠ Barium enema, is contraindicated. Considering a mortality rate of >50% in cases of AMI,

⚠ Watchful waiting would serve only to render a negligence lawsuit against you.

🔖 Key point:

If AMI is suspected surgical exploration should not be delayed

🇨🇦 MCCQE1,2 | #Case_212
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A 45-year-old white male is admitted to the intensive-care unit after being pinned in a car wreck for 2 hours. He has sustained several broken bones and crush injuries to both thighs. On admission his urine is clear but the next morning it is burgundy colored. Some fresh urine is drawn from his Foley catheter and sent for analysis, with the following results:
Specific gravity. ......... 1.020
pH............................... 6.0
Protein........................ 30 mg/dL (N 1-14)
Glucose. .................... negative
Hemoglobin................ 4+
Urobilinogen. ............. 0.1 Ehrlich Units (N 0.1-1.0)
Bile............................. negative
RBCs......................... 1-2/hpf
WBCs. ...................... 0-2/hpf
Occasional hyaline casts

You immediately order a CBC which shows his hematocrit to have dropped 4 percentage points overnight. Visual inspection of the serum shows it is clear. The color of his urine is most likely due to:

a) Myoglobinuria
b) Hematuria from trauma to the urinary tract
c) A transfusion reaction with hemolysis of RBCs and free hemoglobin into the urine
d) Hemoglobinuria resulting from reabsorption of hemoglobin from hematomas
e) Acute porphyria provoked by trauma

🇨🇦 MCCQE1,2 | #Case_212 | #answer
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✅ A

🔎 Explanation

A positive dipstick for hemoglobin without any RBCs noted in the urine sediment indicates either free hemoglobin or myoglobin in the urine. Since the specimen in this case was a fresh sample, significant RBC hemolysis within the urine would not be expected.
Myoglobin is released when skeletal muscle is destroyed by trauma, infarction, or intrinsic muscle disease.

⚠ If the hematuria were due to trauma there would be many RBCs visible on microscopic examination of the urine.

⚠ If a transfusion reaction occurs, haptoglobin binds enough free hemoglobin in the serum to give it a pink coloration. Only when haptoglobin is saturated will the free hemoglobin be excreted in the urine.

⚠ Free hemoglobin resorption from hematomas does not occur.

⚠ Porphyria may cause urine to be burgundy colored, but it is not associated with a positive urine test for hemoglobin

🇨🇦 MCCQE1,2 | #Case_213
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You are called to evaluate a term newborn in the delivery room. The pregnancy and delivery were uneventful, but the baby has remained cyanotic despite routine delivery room care. A
hyperoxia test is performed; the results of which are printed below:
FiO2 = 0.21, PaO2 = 30
FiO2 = 1.00, PaO2 = 40

Which statement is the correct interpretation of the test results above?

a) The test results suggest that the baby has a cardiac defect involving restricted pulmonary blood flow or a separate circulation
b) The baby has a normal PaO2 for a newborn
c) The test results suggest that the baby has underlying neurologic disease
d) The test results suggest that the baby has a cardiac defect involving complete mixing without restricted pulmonary blood flow

🇨🇦 MCCQE1,2 | #Case_213 | #answer
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✅ A

🔎 Explanation

The hyperoxia test is used as an early tool to evaluate the cyanotic neonate to determine if the etiology of the cyanosis is cardiac or non-cardiac in origin. A right radial artery (preductal) blood gas is performed with the child inspiring room air and 100% oxygen. The change in PaO2 with the administration of oxygen issued as a guide to determine the etiology of the cyanosis. A PaO2 of less than 150 with the administration of 100% oxygen suggests a cardiac lesion. The cardiac lesions may be further classified based upon the absolute value of the PaO2. A PaO2 of less than 50 on 100% oxygen suggests a cardiac
disorder, in which there is restricted pulmonary blood flow or a separate venous and arterial circulation, whereas a PaO2 between 50 and 150 on 100% oxygen suggests that there is no restriction of pulmonary blood flow in the presence of complete mixing of oxygenated and deoxygenated blood. In this case, the PaO2 on 100% oxygen was less than 50, suggesting restricting pulmonary blood flow or a separate circulation

🇨🇦 MCCQE1,2 | #Case_214
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A 26-year-old female presents with a 1-year history of recurring abdominal pain associated with intermittent diarrhea, 5-7 days per month. Her pain improves with defecation. She denies blood in her stool and weigh loss. Laboratory tests
(including a CBC, chemistry profile, TSH level, and antibodies for celiac disease) came back normal. Which one of the following would be most appropriate at this point?

a) Colonoscopy
b) An upper GI series with small-bowel follow-through
c) Abdominal CT with contrast
d) A gluten-free diet
e) Loperamide

🇨🇦 MCCQE1,2 | #Case_214 | #answer
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✅ E

🔎 Explanation

This patient has classic symptoms of irritable bowel syndrome (IBS) and meets the Rome criteria by having 3 days per month of abdominal pain for the past 3 months, a change in the frequency of stool, and improvement with defecation. According to current clinical guidelines IBS can be diagnosed by history, physical examination, and routine laboratory

🇨🇦 MCCQE1,2 | #Case_215
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A 68-year-old woman comes to the office for flexible sigmoidoscopy as part of a yearly screening. A 3 cm polyp is found in the sigmoid colon and is removed. She returns now to the office, 6 hours later, complaining of left lower quadrant pain, fever, nausea and vomiting. Vital signs are: temperature 38.1°C (100.6°F), pulse 110/min, respirations 26/min and blood pressure 120/60 mm Hg. Abdominal examination discloses bowel sounds, tenderness and guarding in the left lower
quadrant. Rectal examination shows no stool and only tenderness superiorly The most appropriate next step is to:

a) Obtain an angiogram to rule out intestinal ischemia
b) Obtain immediate consultation with a surgeon
c) Pass a soft rubber rectal tube under fluoroscopy
d) Repeat the flexible sigmoidoscopy in order to evaluate the operative site
e) Start hydrocortisone, intravenously, to decrease any inflammatory response

🇨🇦 MCCQE1,2 | #Case_215 | #answer
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✅ B

🔎 Explanation

The physical findings described clearly suggest a probable colon perforation at the site of the polypectomy, and therefore surgical consultation is warranted. There is no reason to suspect ischemia, and any further instrumentation of the colon is contraindicated. The patient should be prepped for probable surgery with antibiotics and not hydrocortisone since she is already at risk for peritonitis

🇨🇦 MCCQE1,2 | #Case_216
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A 47-year-old female presents to your office with a complaint of hair loss. On examination she has a localized 2-cm round area of complete hair loss on the top of her scalp. Further studies do not reveal an underlying metabolic or infectious disorder. Which one of the following is the most appropriate initial treatment?

a) Topical minoxidil
b) Topical immunotherapy
c) Intralesional triamcinolone
d) Oral finasteride
e) Oral spironolactone

🇨🇦 MCCQE1,2 | #Case_216 | #answer
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✅ C

🔎 Explanation

These findings are consistent with alopecia areata, which is thought to be caused by a localized autoimmune reaction to hair follicles. It occasionally spreads to involve the entire scalp (alopecia totalis) or the entire body (alopecia universalis). Spontaneous recovery usually occurs within 6-12 months, although areas of regrowth may be pigmented differently. Recovery is less likely if the condition persists for longer than a year, worsens, or begins before puberty. The initial treatment of choice for patients older than 10 years of age, in cases where alopecia areata affects less than 50% of the scalp, is intralesional corticosteroid injections.

⚠ Minoxidil is an alternative for children younger than 10 years of age or for patients in whom alopecia areata affects more than 50% of the scalp.

⚠ While topical immunotherapy is the most effective treatment for chronic severe alopecia areata, it has the potential for severe side effects and should not be used as a first-line agent.

⚠ Finasteride inhibits 5-reductase type 2, resulting in a decrease in dihydrotestosterone levels, and is used in the treatment of androgenic alopecia (male-pattern baldness). Similarly, spironolactone is sometimes used for androgenic alopecia because it is an aldosterone antagonist with antiandrogenic effects.

🇨🇦 MCCQE1,2 | #Case_217
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A 78-year-old white male is scheduled to undergo CT with contrast. His current diagnoses include type 2 diabetes mellitus, heart failure, anemia of chronic disease, and renal insufficiency. Evidence supports the use of which one of the following to reduce the risk of contrast-induced nephropathy in this patient?

a) Intravenous furosemide
b) Ascorbic acid
c) Calcium antagonists
d) Isotonic bicarbonate infusion
e) High osmolar contrast media

🇨🇦 MCCQE1,2 | #Case_217 | #answer
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✅ D

🔎 Explanation

Prospective randomized trials examining the risk for contrast-induced nephropathy have identified significant differences between contrast agents due to their physiochemical properties. Low-osmolar or iso-osmolar contrast media should be used to prevent contrast-induced nephropathy in at-risk patients. The volume of contrast medium should be as low as possible. Evidence also supports hydration before the procedure, preferably with isotonic saline or isotonic sodium bicarbonate solution. There is limited evidence that any pharmacologic intervention will prevent contrast-induced nephropathy

🇨🇦 MCCQE1,2 | #Case_218
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A 65-year-old male presents with a 1-month history of problems passing urine. He says that his bladder will feel full when he needs to urinate, but the urine stream is weak and his bladder does not feel as if it has emptied completely. The symptoms have become increasingly severe over the past week. Other symptoms include upper respiratory congestion for 3 days which he has treated with an over-the-counter decongestant with some relief, constipation with no passage of stool in the past 9 days, and increasing low back pain incompletely relieved with ibuprofen, with associated weakness in both legs.Examination shows a healthy-appearing male who is moderately overweight. He is afebrile and vital signs are normal. There is no abdominal tenderness and no masses are detected. A rectal examination reveals a large amount of hard stool in the rectum; a markedly enlarged (4+), boggy, tender prostate gland; laxity of the anal sphincter; and numbness in the perianal area. Urinalysis shows trace protein and 10-20 WBCs/hpf. Ultrasonography shows a post-void residual volume of 250 mL (normal for age < 100). Which one of the following must be done urgently in this patient?

a) Foley catheterization
b) Hospitalization for intravenous antibiotics
c) Digital disimpaction of the rectum, and Fleet enemas until clear
d) MRI of the lumbosacral spine