10 MEDICAL QUESTIONS OF THE DAY WITH ANSWERS BY RICHARD MITCHELL

1. A 26 year old woman comes to the emergency department with vomiting, abdominal pain and  
tachypnoea. Her breath has a fruity smell. She has a heart rate of 99 beats/minute and a  
respiratory rate of 30 breaths/minute. Her blood pressure is 110/70 mmHg. Her blood and urine  
results show:
Blood Ketones 3.3 mmol/L (high)
Urine Ketones +++
Venous pH 7.2 (low)
Blood Glucose 22 mmol/L (high)
What is the SINGLE most appropriate immediate management?
A. Intravenous fluids followed by insulin
B. Intravenous dextrose
C. Oral rehydration
D. Subcutaneous insulin immediately
E. Intravenous antibiotics

CORRECT ANSWER IS A

 explanation : Intravenous fluids followed by insulin  EXPLANATION: It is clear in this question that this man is suffering from diabetic ketoacidosis. Most DKA patients have a depletion of around 5 litres thus initial intravenous normal saline is so important. 0.9% saline is the replacement fluid of choice. Insulin should be infused continuously at 0.1u/kg/h.

2.   A 42 year old lady has unexplained milk secretion from her nipples. Her last menstrual period was 6 months ago. She says she has been experiencing a loss of libido.

What is the SINGLE most likely diagnosis?  

A. Hyperprolactinaemia B. Cushing’s syndrome C. Pheochromocytoma D. Hyperthyroidism E. Hypoparathyroidism

CORRECT ANSWER IS A

ANSWER: Hyperprolactinaemia  EXPLANATION: Galactorrhoea is one of the features of hyperprolactinaemia (although it is uncommon in a premenopausal woman).  Hirsutism, amenorrhoea, vaginal dryness, loss of libido are features which are consistent with hyperprolactinaemia.

 

3.    A 55 year old man who is a chronic alcoholic stops drinking alcohol 4 days ago.  He usually drinks around 5 cans of beer a day for the past 6 years.  Since stopping, he has been feeling nauseous and has been vomiting several times a day.  There is no blood in his vomitus and he reports normal coloured stool.  He denies sweating, palpitations, and tremors. 

What is the SINGLE most likely electrolyte abnormality?  

A. Hyponatraemia B. Hypermagnesemia C. Hypercalcemia D. Hyperkaleimia E. Hypokaleimia

CORRECT ANSWER IS E

ANSWER: Hypokaleimia  EXPLANATION: It is clear that the likely electrolyte disbalance would be a low potassium.  This is because he has been vomiting severely over the past few days.  Firstly, potassium may be lost with vomitus.  Secondly, metabolic alkalosis would be present due to excretion of hydrochloric acid with vomitus and state of volume depletion which would additionally cause a loss of potassium through the renal system via aldosterone-mediated mechanisms.    Another reason for hypokaleimia is that he is a chronic alcoholic.  Many patients with potassium deficiency are also magnesium deficient.  So if the potassium was very low, a magnesium level should be ordered.  He would also require an ECG, replacement of potassium, and a cardiac monitor as cardiac arrhythmias are the most serious emergency due to hypokaleimia.  If the magnesium levels came back low, he would also require magnesium replacement.  

4. Q-50 A 40 year old male with pre-existing glomerulonephritis deteriorates and presents with oliguria.  Lab results show the following:  Serum K+ = 7.8mmol/L Urea = 13 mmol/L Creatinine = 342 mmol/L GFR = 19mL/h. 

What is the SINGLE most appropriate initial management?  

A. Calcium supplement B. Calcium resonate enema 30g C. Urgent haemodialysis D. Loop diuretics E. Intravenous calcium gluconate

CORRECT ANSWER IS E

ANSWER: Intravenous calcium gluconate  EXPLANATION: Calcium gluconate is the most appropriate initial management as it is used to prevent cardiac arrhythmia.  It prevents cardiac arrest or life threatening cardiac arrhythmia to buy time till definitive measures are taken.

5. 31 year old man has tremors, profuse sweating and palpitations.  His blood pressure was measured at 160/115 mmHg but dropped to 139/92 on standing. 

What is the SINGLE most likely diagnosis?  

A. Hyperthyroidism B. Panic attacks C. Essential hypertension D. Phaeochromocytoma E. Generalized anxiety disorder

CORRECT ANSWER IS D

Phaeochromocytoma  EXPLANATION: Postural hypotension is defined as a reduction in systolic blood pressure of 20 mmHg or more after standing for at least one minute.  Postural hypotension can be seen in phaeochromocytoma.