Oliver Munroe is a 79-year-old man who is brought to the hospital emergency department by ambulance after being found collapsed at home by his daughter.  He is semi-conscious, disoriented and breathing rapidly.  He appears to have vomited blood (haematemesis).  The ambulance officer finds a blood pressure of 60/40, pulse 120 and respiration rate, 28 breaths/min. 
Question 7 Give two hypotheses to account for Mr Munroe’s collapse and rapid breathing.  For each hypothesis outline a sequence of events that might have led to his collapse.    

(12 marks) 

Question 8:Describe four key laboratory tests that would help you distinguish between your hypotheses.  Explain how you would interpret possible results from these tests in relation to your hypotheses. (13 marks)His daughter reveals that Mr Munroe has a recent history of melaena (black tar-like stools).  Laboratory tests on his plasma and on an arterial blood sample gave the following results:

Value Units Reference
Na+ 139 mmol/L 135-145
K+ 4.3 mmol/L 3.2-43
Cl- 99 mmol/L 99-109
HCO3- 6 mmol/L 23-33
Urea 24.0 mmol/L 3-8
Creatinine 240 mmol/L 90-120
Glucose 6.5 mmol/L 3-7.8
Lactate 28 mmol/L <2.0
Beta-hydroxybuterate <0.3 mmol/L <0.3


Haemoglobin 57 g/L 130-175
PO2 90 mmHg 80-100
PCO2 22 mmHg 35-45
HCO3- 7 mmHg 24-32
pH 7.13


Question 9:State what is now your preferred hypothesis to account for Mr Munroe’s collapse and rapid breathing. Provide an explanation for each of the laboratory findings, indicating how they relate to your hypothesis, where appropriate.  (20 marks)


John  Davidson,  a  57  year  old  man  presents  to  his  general  practitioner  with  symptoms  of progressive  tiredness  over  6  months,  shortness  of  breath  on  exertion  for  two  weeks  with associated palpitations. He is a lawyer working 55 hours per week, eating take away food and not exercising to keep  fit.  His BMI is 30.  He has no personal or familial cardiac history.  He also gives a vague story of increased thirst and getting up at night to pass urine.  On examination he is pale but not jaundiced. Pulse rate 90 beats per minute and respiratory rate 18 breaths per minute at rest, with no evidence of cardiac failure. He appears mildly dehydrated. Abdominal examination is unremarkable. 
Question  10 Formulate two (2) different clinical hypotheses that could explain this man’s symptoms. For each hypothesis explain how the symptoms and examination findings contribute to this case scenario and  the mechanisms underlying these conditions.  (15 marks) 

Reference Range
Hb 90mg/L 115-150
MCV 74 fL 80-100
WCC 8x109/L 4-10
Platelets 500x109/L 150-450

Sodium 141 mmol/L 137-145
Potassium 4.4 mmol/L 3.2-4.4
Chloride 107 mmol/L 100-109
Bicarbonate 26 mmol/L 22-32
Glucose 16.4 mmol/L 3.2-5.5
Creatinine 88 mcmol/L 50-120

Question  11.  How would John’s anaemia be broadly classified given only the above laboratory information? Give 3 separate causes of this class of anaemia. (4 marks)  

Question  12.  Briefly discuss the laboratory tests required to distinguish between these 3 causes of anaemia. (6 marks) 

Question  13.  Suggest the most likely explanation for John’s glucosuria.  In your answer, include an indication of the likely underlying disorder, explaining your reasoning. (9 marks)