OSCE Clinical Reasoning 5 — Questions and Answers
Question 1: A 40-year-old nurse presents with recurrent episodes of diaphoresis, tremor, and confusion that resolve after eating. Fasting glucose is 2.1 mmol/L (38 mg/dL). What is the most likely diagnosis?
- Type 1 diabetes with hypoglycemia
- Insulinoma (Correct answer)
- Reactive hypoglycemia
- Factitious hypoglycemia from insulin injection
Correct answer: Insulinoma
Fasting hypoglycemia with neuroglycopenic symptoms in a non-diabetic patient is characteristic of an insulinoma until proven otherwise.
Question 2: Which of the following best represents a 'System 2' thinking approach in clinical reasoning?
- Recognizing a classic presentation of appendicitis at a glance
- Deliberately working through a differential diagnosis using structured analysis (Correct answer)
- Automatically prescribing a familiar drug for a familiar complaint
- Using a gut feeling to decide on admission vs. discharge
Correct answer: Deliberately working through a differential diagnosis using structured analysis
System 2 thinking is slow, deliberate, and analytical — it counterbalances the fast, intuitive System 1 and is particularly important for complex or atypical cases.
Question 3: A 35-year-old man presents with joint pain, a photosensitive facial rash in a butterfly distribution, and proteinuria. What is the most likely diagnosis?
- Rheumatoid arthritis
- Systemic lupus erythematosus (Correct answer)
- Dermatomyositis
- Psoriatic arthritis
Correct answer: Systemic lupus erythematosus
The triad of butterfly malar rash, polyarthritis, and renal involvement in a young woman is the classic presentation of systemic lupus erythematosus.
Question 4: During an OSCE communication station, a patient refuses a recommended blood transfusion citing religious beliefs. The patient is competent and fully informed. What is the ethically correct action?
- Proceed with transfusion to save the patient's life
- Seek a court order to override the patient's decision
- Respect the patient's refusal and explore alternative management (Correct answer)
- Involve the next of kin to persuade the patient
Correct answer: Respect the patient's refusal and explore alternative management
A competent, informed adult's refusal of treatment must be respected regardless of the clinician's opinion; alternatives should then be explored.
Question 5: A 65-year-old man with type 2 diabetes presents with a painless change in vision. Fundoscopy reveals dot and blot hemorrhages, hard exudates, and new vessel formation. What stage of retinopathy is this?
- Background (non-proliferative) retinopathy
- Proliferative diabetic retinopathy (Correct answer)
- Pre-proliferative retinopathy
- Diabetic maculopathy
Correct answer: Proliferative diabetic retinopathy
New vessel formation (neovascularization) defines proliferative diabetic retinopathy, which carries risk of vitreous hemorrhage and requires urgent ophthalmology referral.
Question 6: A clinical student presents a case and concludes 'the patient has pneumonia because they have a fever.' What logical error does this illustrate?
- False dichotomy
- Circular reasoning
- Affirming the consequent (Correct answer)
- Overgeneralization
Correct answer: Affirming the consequent
Affirming the consequent means assuming that because a finding (fever) is present in a disease (pneumonia), the disease must be the cause — ignoring other causes of fever.
Question 7: A 78-year-old woman is admitted with an acute confusion state. Her daughter says she was fine this morning. What is the most likely diagnosis given the acute onset?
- Dementia
- Delirium (Correct answer)
- Depression
- Psychosis
Correct answer: Delirium
Acute onset confusion fluctuating over hours in an elderly patient is delirium until proven otherwise; dementia is chronic and does not present this way.
OSCE Clinical Reasoning 5
A 40-year-old nurse presents with recurrent episodes of diaphoresis, tremor, and confusion that resolve after eating.
Fasting glucose is 2.1 mmol/L (38 mg/dL).
What is the most likely diagnosis?