Diabetes CPC

Question 1

Give 2 diagnostic results of diabetes

Answer 1

Fasting plasma glucose > 7.0mM
HbA1c > 6.5% (48mmol/mol)

Question 2

48F unconscious
Vomiting, polyuria + polydipsia, SOB, dehydrated
Poorly controlled HTN + Obese
BP 80/40
Why is she unconscious?
A. Diabetic ketoacidosis
B. Hyperosmolar non-ketotic coma
C. Severe hypotension
D. Stroke
E. Renal failure

Answer 2

Low blood flow to brain
A or B - need tests to distinguish

Question 3

48F unconscious
Vomiting, polyuria + polydipsia, SOB, dehydrated
Poorly controlled HTN + Obese
BP 80/40
What test should we do?
A. ABG
B. CT brain
C. CXR
D. FBC
E. ECG

Answer 3

A. ABG

Question 4

pH 7.65
PCO2 6.1 kPa
PO2 15 kPa
What is the acid/base abnormality?

Answer 4

Metabolic alkalosis

High pH: alkalosis
High CO2: not hyperventilating

Question 5

Label the diagram A-D

Answer 5

A: Metabolic acidosis
B: Respiratory acidosis
C: Respiratory alkalosis
D: Metabolic alkalosis

Question 6

Give 3 causes of metabolic alkalosis

Answer 6

H+ loss e.g. vomiting
Hypokalaemia
Ingestion of bicarbonate

Question 7

Describe the process of respiratory compensation in metabolic alkalosis

Answer 7

Metabolic alkalosis inhibits ventilation
CO2 increases (though hypoxia prevents significant hypoventilation)
Improvement of pH at expense of making CO2 worse

Question 8

Describe compensatory mechanisms in renal disease

Answer 8

Acidosis: Lungs hyperventilate
Alkalosis: Underbreathing is blocked by hypoxia- CO2 won’t rise much as it should as brain forces breathing

Question 9

In a patient with high pH and high CO2 that is not hyperventilating, what will the bicarbonate be?

Answer 9

High

Question 10

What equation can be used to calculate osmolality?

Answer 10

2 (Na + K) + Urea + Glucose

Question 11

What equation is used to calculate the anion gap?

Answer 11

Na + K
- Cl -Bicarbonate

Question 12

How do ketones influence the anion gap?

Answer 12

Ketones are anions
Result in high anion gap

Question 13

Give 3 sources of potassium loss in hypokalaemia

Answer 13

Intestinal: D+V, fistula
Renal: Mineralocorticoid excess, diuretics, renal tubular disease
Redistribution: Insulin, alkalosis

Question 14

What effect does hypokalaemia have on cells?

Answer 14

1. Low K+
2. More H+ shifts into cells instead of K+
3. Extracellular alkalosis
   - Hypokalaemic alkalosis

Question 15

What effect does alkalosis have on cells?

Answer 15

1. Low H+
2. More K+ shifts into cells instead of H+
3. Hypokalaemia-
   Hypokalaemic alkalosis

Question 16

What effect does hypokalaemia have in the kidney?

Answer 16

Lack of intracellular K+ leads to increased excretion of H+ in exchange for Na+
Production of acid urine
Generation of bicarbonate

Question 17

48F unconscious
Vomiting, polyuria + polydipsia, SOB, dehydrated
Poorly controlled HTN + Obese + DM
Previous fractured hip
Wound on shin not healing properly
BP 80/40
What is the diagnosis?
A. Cystic fibrosis
B. SLE
C. Cushing’s syndrome
D. Sjogren’s
E. Osteoporosis

Answer 17

C. Cushing’s syndrome

Question 18

Patient has Cushing’s syndrome.
ACTH: 250
Cortisol: 3120
Dexamethasone failed to suppress
Low dose dex: Cortisol= 3100
High dose dex: Cortisol= 2990
What is the cause?
A. Pituitary Cushing’s
B. Ectopic ACTH
C. Adrenal tumour

Answer 18

B. Ectopic ACTH

Adrenal tumour would suppress ACTH

Due to low K+, likely ectopic ACTH
as really high Cortisol starts binding Aldosterone receptor

Question 19

Examination: Reduced expansion on right
Percussion: dull on right
Vocal resonance: increased on right
What is indicated by these findings?
A. Pleural effusion
B. Pneumothorax
C. Collapse and consolidation
D. COPD
E. Bronchiectasis

Answer 19

C. Collapse + consolidation

Question 20

Patient very hypokalaemic and hypotensive.
Osmolality: 380 mosm/kg
What management is required?

Answer 20

Rehydrate cautiously
Replace K+ with caution

Question 21

Despite rehydration and potassium replacement, patient does not pass urine.
Na: 145
K: 5.2
U: 50
Creat: 500
Glucose: 34.0
What is the differential?
How can these be distinguished?

Answer 21

Acute renal failure (ATN due to dehydration)
Chronic renal failure (diabetic renal disease)

Renal biopsy

Question 22

What cardiac consequences arise from potassium disturbance>

Answer 22

Hypokalaemia: Ventricular fibrillation
Hyperkalaemia: Asystole

Question 23

If acute tubular necrosis is found on biopsy, what treatment is necessary?

Answer 23

Dialysis for 3w
(complete recovery)

Question 24

If diabetic glomerular kidney disease is found on biopsy, what treatment is necessary?

Answer 24

Lifelong dialysis (is End stage renal failure)

Question 25

What is shown here?

Answer 25

Normal glomerulus

Question 26

What is shown here?

Answer 26

RHS: normal glomerulus
LHS: Tubular necrosis, damaged cells

Question 27

What is shown here? Which condition is this seen in?

Answer 27

Adrenal with very thickened zona fasciculata (driven by ACTH)
Ectopic ACTH

Question 28

What is shown here? What condition is this seen in?

Answer 28

Adrenal with normal zona fasciculata
Pituitary Cushing’s

Question 29

What is shown in the ECG? Which artery is occluded?

Answer 29

Inferior STEMI
ST elevation in II, II, + aVF with reciprocal changes
Right Coronary Artery occlusion

Question 30

New onset difficulty walking
Tone increased on RHS
Power reduced on RHS
Brisk reflexes on RHS
Diagnosis?
A. Right Upper Motor Nerone Signs
B. Right Lower Motor Nerone Signs
What investigation should be performed?
What is the likely cause of this?

Answer 30

A. Right Upper Motor Neurone signs

CT head

Slow growing left sided tumour

(slow onset makes stroke unlikely)

Question 31

What is seen here?

Answer 31

Previous MI
Scar tissue indicated by arrow

Question 32

What is seen here?

Answer 32

Brain lesion packed with ACTH
Met to brain, also producing ACTH