Clinical Chemistry Cases - Diabetes

Question 1

Diabetes is confrimed by

A) A fasting plasma glucose of over 7.0mM
B) A 2 hour plasma glucose in a GTT of 9.0mM
C) A 2 hour plasma glucose in a GTT of 10.0mM
D) A 2 hour plasma glucose in a GTT of 11.0mM
E) HbA1c > 6.5% (48mmol/mol)

Answer 1

A) and E)

Question 2

First presented in February 2002.
48 year old unconscious.
Acutely unwell a few days.
Vomiting
Polyuria and polydipsia
Breathless
Dehydrated

Past Medical History (PMH)
Appendicectomy
Osteoporosis
Poorly controlled hypertension

DH:
Amlodipine 10 mg
Atenolol 100 mg

Examination: obese

Very dehydrated
BP 80 / 40
Urine dipstick: 4+ glycosuria

Why is she unconscious ?
A) Diabetic ketoacidosis
B) Hyperosmolar non ketotic coma
C) Severe hypotension
D) Stroke
E) Renal failure

Answer 2

All of them could be true

Question 3

Longstanding hypertension and diabetes
Previous fractured hip
Slowly worsening obesity.
Wound on shin that did not heal
What is the diagnosis ?
A. Cystic fibrosis		
B. SLE				
C. Cushing’s syndrome
D. Sjogren’s 
E. Osteoporosis

Answer 3

C. Cushing’s syndrome

Question 4

ACTH  250 (very high)
Cortisol  3120 nM (very high)

Dexamethasone failed to suppress
Low dose dex: cortisol = 3100 nM
High dose dex: cortisol = 2990 nM
(totally failed to suppress).

A. Pituitary Cushing’s
B. Ectopic ACTH
C. Adrenal tumour

Answer 4

B) Ectopic

Could argue pituitary cushings as IPSS 9Pituitary sample) gold standard to rule out pituitary

Question 5

Why such severe hypokalaemia?

Answer 5

Ectopic ACTH gives the highest cortisol out of all the causes.

Hypokalaemia indicates ectopic ACTH

The high levels of cortisol start bind to aldosterone receptor causing hypokalaemia

Question 6

Examination reduced on RIGHT
Percussion: dull on RIGHT
Vocal resonance: increased on RIGHT

A) pleural effusion
B) pneumothorax
C) collapse and consolidation
D) COPD
E) bronchiectasis

Answer 6

C) Collapse and consolidation

Fluid causes dullness and reduced vocal resonance

Vocal resonance increase indicates denser or inflames lung tissue e.g. Pneumonia

Vocal resonance decrease indicates fluid/air

Dullness indicates solid or fluid

Hyperresonant/tympanic indicates air

Question 7

She does not pass any urine.
What should you do ?

Na 145 K 4.0
U 45 Creat 450.

What is the differential diagnosis ?

Answer 7

Acute renal failure (dehydration)

Chronic renal failure (diabetes)

Question 8

What are adult fluid management guidelines?

Answer 8

1. Does the patient need fluid resuc (Systolic BP < 100, HR > 90, cap refill > 2 or peripheries cold to touch)
   
   • 500 ml crystaloid (130-154mmol range) in less than 15 min
     
     • Can repeat up to 2000ml (3 more times)
       
       • Call senior
2. Patient is stable and routine maintenence
   
   • 25-30 ml/kg/day of water
   • 1 mmol/kg/day of sodium, potassium, and chloride
   • 50-100 g/day of glucose
   • If more than 3 days of maintenence, consider NG or PEG feeding
3. If risk of fluid overload e.g. Lung or cerebral issues or SIADH, do less fluid

Question 9

Na: 145, K: 5.2, U 50, creat 500, Glucose 34.0

Acute renal failure ? (ATN)
Chronic renal failure ? (diabetic renal disease)

How can we distinguish them ?

Answer 9

Renal biopsy

Question 10

Chest pain on exertion

ST elevation on ECG (2/3/AVF)

Diagnosis?

Answer 10

MI (Inferior Wall)

Question 11

MI immediate managemen and Long Term managementt?

Answer 11

MONA + Clopidogrel + PCI (Angioplasty)

BASA (Bblocker, ACEi, Statin, Aspirin/Aspirin + Clopidogrel)

Question 12

New onset difficulty walking.
Tone increased on right
Power reduced on right
Brisk reflexes on right

Diagnosis ?
A. Right Upper Motor Neurone Signs
B. Right Lower Motor Neurone Signs
C. No idea

Answer 12

A) Right Upper

Hyperreflexia, Hypertonia, and Reduced power are UMN signs cos lower neurones still working and sending some signals

Question 13

Differential for UMN signs?

Answer 13

Stroke if sudden onset

Tumour is gradual