Metabolic

Question 1

Typically, why are ketones not present in those with type II diabetes (in acute setting)?

Answer 1

Insulin (present in those with type II) inhibits lipolysis in the adipocytes therefore ketones are generally not present
Although insulin resistance prohibits glucose uptake, the effects of insulin on lipolysis are not inhibited

Question 2

Discuss signs and symptoms of DKA

Answer 2

• Known diabetes of features of diabetes
• Nausea and vomiting
• Abdominal pain
• Dehydration (high levels of glucose in the blood causes fluid to move out of the cells)
• Hyperventilation - kussmal
• Reduced consciousness
• Ketone breath

Question 3

Electrolyte findings in DKA

Answer 3

Hyponatraemia because of the osmotic shift of water, plasma sodium concentrations fall, sodium is also lost via diuresis
Hyperkalaemia is common due to extracellular shift shift of potassium caused by insulin insufficiency

Question 4

Discuss the mechanisms behind hypercalcaemia of malignancy

Answer 4

1. Paraneoplastic syndrome - tumour secretion of PTH related peptide (e.g. SCC, renal and ovarian)
2. Non PTHr - calcitriol (vitamin D) mediated hypercalcaemia assocaited with lymphomas (this is also seen in granulomatous diseases such as active sarcoidosis or TB)
3. Osteolytic hypercalcaemia

Question 5

How can gentamicin cause acute renal failure

Answer 5

acute interstitial nephritis

Question 6

Where is most sodium reabsorbed in the nephron ?

Answer 6

Proximal convoluted tubule

Question 7

Via what mechanism is sodium reabsorbed in the DCT and collecting ducts?

Answer 7

Aldosterone mediated

secretion of potassium and absorption of sodium (ion exchanger)

Question 8

From when and how often is diabetic eye disease screened for in the NHS?

Answer 8

from 12 - annually

Question 9

Metabolic abnormalities associated with severe vomiting

Answer 9

Metabolic alkalosis
Hyponatraemia, hypokalaemia and hypochloraemia - The kidneys compensate for these losses by retaining sodium in the collecting ducts at the expense of hydrogen ions (hydrogen ions are also lost from the GI tract)

Question 10

Why are patients with nephrotic syndrome at higher risk of VTE?

Answer 10

Patients with nephrotic syndrome are at a higher risk of VTE due to the loss of anti-thrombin III in urine. Anti-thrombin III inhibits antagonises the action of thrombin and therefore loss of anti-thrombin results in unopposed thrombin activity creating a pro-coagulant state and therefore prophylactic LMWH is recommended.

Question 11

Explain the physiology behind hyperchloraemic acidosis

Answer 11

• Normal anion gap acidosis
• Loss of Bicarbonate ions results in CL- ion retention to compensate
• reduced bicarbonate ions to buffer H+ leads to acidosis
• Bicarbonate is lost in diarrhoea and renal tubular acidosis

Question 12

What happens to serum calcium and phosphate when PTH is increased (e.g. in primary hyperparathyroidism)

Answer 12

Calcium increases 
Phosphate decreases (as PTH acts on kidney to increase calcium reabsorption and excrete phosphate)

Question 13

Causes of hyperkalaemia

Answer 13

Causes of hyperkalaemia:
acute kidney injury
drugs*: potassium sparing diuretics, ACE inhibitors, angiotensin 2 receptor blockers, spironolactone, ciclosporin, heparin**
metabolic acidosis
Addison's disease
rhabdomyolysis
massive blood transfusion

Question 14

Define Nephrotic syndrome

Answer 14

• Proteinuria > 3g
• Hypoalbuminaemia <25 g/l
• Oedema
• Hyperlipidaemia

Question 15

Describe the pathophysiology of minimal change glomerulonephritis

Answer 15

Nephrotic syndrome caused by podocyte fusion

Question 16

Discuss fluid restriction in dialysis patients

Answer 16

• Fluid restriction
• Those who pass urine may be able to drink more
• Those anuric should be restricted to fluids matching their insensible fluid loss (roughly 750ml)