OSCE Diagnostic Skills 5 — Questions and Answers
Question 1: A patient is found to have shifting dullness and a fluid thrill on abdominal examination. These signs indicate:
- Ascites (Correct answer)
- Bowel obstruction
- Gaseous distension
- Hepatomegaly
Correct answer: Ascites
Shifting dullness and a fluid thrill are classic signs of free peritoneal fluid (ascites), especially when greater than 1500 mL.
Question 2: Which bedside test is used to differentiate central from peripheral vertigo?
- Dix-Hallpike test
- Romberg's test
- Unterberger's test
- Head impulse test (Correct answer)
Correct answer: Head impulse test
The head impulse (thrust) test is positive in peripheral vertigo (compensatory saccade seen) and typically negative in central causes, helping differentiate the two.
Question 3: A 25-year-old athlete presents with a painful, swollen knee after twisting injury. A positive anterior drawer test suggests injury to which structure?
- Anterior cruciate ligament (Correct answer)
- Posterior cruciate ligament
- Medial meniscus
- Medial collateral ligament
Correct answer: Anterior cruciate ligament
Anterior drawer test assesses ACL integrity; anterior tibial displacement on the femur indicates ACL rupture.
Question 4: On auscultation of the abdomen, which finding would suggest bowel obstruction rather than paralytic ileus?
- High-pitched tinkling bowel sounds (Correct answer)
- Absent bowel sounds
- Soft normal bowel sounds
- Friction rub
Correct answer: High-pitched tinkling bowel sounds
Mechanical bowel obstruction produces hyperactive, high-pitched tinkling sounds from peristalsis against obstructed bowel, whereas paralytic ileus produces absent sounds.
Question 5: A patient's urine dipstick shows 3+ protein and 3+ blood. Which investigation should follow to evaluate for glomerulonephritis?
- Urine microscopy for red cell casts (Correct answer)
- 24-hour urine protein only
- Renal ultrasound only
- Urine culture
Correct answer: Urine microscopy for red cell casts
Red cell casts on urine microscopy are pathognomonic of glomerulonephritis, confirming that bleeding originates from the glomerulus.
Question 6: When interpreting spirometry, a FEV1/FVC ratio less than 0.70 with a reduced FEV1 and normal FVC indicates:
- Obstructive pattern (Correct answer)
- Restrictive pattern
- Mixed pattern
- Normal spirometry
Correct answer: Obstructive pattern
A reduced FEV1/FVC ratio below 0.70 defines obstruction, as seen in asthma and COPD, where airflow is limited during forced expiration.
Question 7: A newborn is found to have a unilateral absent red reflex on ophthalmoscopy. The most important diagnosis to exclude urgently is:
- Retinoblastoma (Correct answer)
- Congenital cataract
- Glaucoma
- Retinal detachment
Correct answer: Retinoblastoma
An absent red reflex in a neonate must prompt urgent referral to exclude retinoblastoma, a malignant intraocular tumour that is life-threatening if missed.
OSCE Diagnostic Skills 5
A patient is found to have shifting dullness and a fluid thrill on abdominal examination.
These signs indicate: