CHEMPATH: Diabetes CPC Flashcards Preview

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Flashcards in CHEMPATH: Diabetes CPC Deck (17)
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1
Q
A

first and last are correct

4th is incorrect because it needs to be 11.1

2
Q

What is the criteria for diabetes diagnosis?

A

Symptoms + 1 diabetes test result

No symptoms + 2 diabetes test results

  • Fasting ≥7.0mmol/L [whole fasted blood ≥6.1mmol/L]
  • OGTT ≥11.1mmol>L
  • HbA1c >6.5% / >48mmol/mol
  • Random ≥11.1mmol/L
3
Q

What is the cut off for IGT and IFG?

A

Impaired Glucose Tolerance (IGT) = OGTT, random = 7.8-11.1 mmol/L

Impaired Fasting Glucose (IFG) = Fasting = 6.1-7.0 mmol/L

4
Q

What is the aBG abnormality?

pH 7.65; pCO2 6.1kPa (4.7-6.0); pO2 15kPa

A

Metabolic acidosis with partial respiratory compensation

Compensation makes the pH better and the CO2 worse

5
Q

What are the causes of metabolc alkalosis?

A

Causes of metabolic alkalosis:

  • H+ loss (i.e. vomiting)
  • Hypokalaemia (and alkalosis)
  • Ingestion of bicarbonate (i.e. lots of rennie
6
Q

What is the osmolality formula?

A

2(Na + K) + U + G

7
Q

In addition to bicarb, and all the others in the osmolality formula, what other result is needed to calculate anion gap?

A

Anion gap = Na + K – Cl – bicarb

8
Q

What is the osmolality and anion gap?

  • Bicarbonate = 55mM (20-24)
  • Na = 145 ;
  • K = 2.5
  • U = 40
  • pH = 7.65
  • Glucose = 46
  • Chloride = 80
A
  • Osmolality = 2(Na + K) + U + G = 2(145+2.5) + 40 + 46 = 381 mOsm/kg
  • Anion gap = Na + K – Cl – bicarb = 145 + 2.5 – 80 – 55 = 12
9
Q

Is this DKA?

  • Bicarbonate = 55mM (20-24)
  • Na = 145 ;
  • K = 2.5
  • U = 40
  • pH = 7.65
  • Glucose = 46
  • Chloride = 80
A

No - this is hypokalaemic alkalosis

10
Q

What are the causes of hypokalaemia?

A
  • GI losses (diarrhoea > vomiting, fistulas)
  • Renal losses –> low K+ + alkalosis
    • MR excess
      • Hyperaldosteronism/Conn’s
      • Cushing’s
    • Increased Na+ delivery to DCT
    • Osmotic diuresis
  • Redistribution into cells
    • Beta-agonists - think hyperkalaemia tx
    • Insulin / insulinomas - think hyperkalaemia tx
    • Alkalosis
  • Rare causes
    • RTA T1, T2
    • Hypomagnesaemia
      • Low Mg2+ means you won’t be able to bring back up a ¯ K+ and so you have to correct the Mg2+ before you attempt to correct any ¯ K+
11
Q

Where do thizide diuretics/loop diuretics affect the renal tubule?

A
  • Triple- or co-transporter is blocked à less Na+ is resorbed in the ascending LoH –> more goes to DCT
    • Triple = Loop diuretics (furosemide)
    • Co-transporter = Thiazides (bendroflumethiazide)
  • More Na+ reaches and is absorbed in the DCT à a more electronegative nephron
  • This results in loss of K+ down the electrochemical gradient through ROMK channels
12
Q

Blood results:

  • ACTH = 250 (very high); Cortisol 3220nM (very high)
  • Dexamethasone failed to suppress the axis
  • Low dose; cortisol = 3100nM
  • High dose; cortisol = 2990nM (i.e. totally failed to suppress)

What is the cause? Ectopic/adrenal tumour/pituitary disease?

A

Ectopic

  • Pituitary disease would be suppressed by a high-dose test
  • Adrenal tumours would suppress ACTH
13
Q

What is a cause of ectopic ACTH?

A

Lung cancer (SCLS)

14
Q

Respiratory exam shows this:

  • Dull percussion on right side
  • Vocal resonance increased on right side

What is the cause?

A

Suggests right-side collapse and consolidation

15
Q

How can you distinguish between acute and chronic renal failure?

A

Biopsy

16
Q

What is shown on this renal biopsy of the patient? What is the management of ATN?

A
  • Shows very dehydrated tubules
  • Tubules are necrosed but glomeruli intact
  • This indicated ATN
  • If ATN, dialyse for 3 weeks and they will recover
  • If diabetic glomerular kidney disease (i.e. end-stage renal failure), they need lifelong dialysis
17
Q

What is shown on this ECG?

A

II, III, aVF = inferior MI

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