Renal

Question 1

What 3 parts are the glomerular filtration barrier made up of?

Answer 1

• Epithelial cells of the bowmans capsule
• Glomerular basement membrane
• Fenestrated capillary endothelium

Question 2

What forms the visceral layer of renal corpuscle in the glomerulus?

Answer 2

Podocytes

Question 3

a) What is the glomerular filtration rate?

b) What methods are used to assess GFR?

Answer 3

a) The sun of the filtration rates in all the functioning nephrons - the volume of plasma filtered by the glomerulus per unit of time
b) - Creatine clearance - Plasma creating concentration - Estimation equation e.e.g Cockrofts Gault, MDRD

Question 4

What is a healthy

a) GFR for women
b) GFR for men
c) Urine output

Answer 4

a) 95 +/- 20 ml/min
b) 120 +/- 25 ml/min
c) 2-3 L/day

Question 5

What is creatine and where is it filtered?

Answer 5

Derived from metabolism of skeletal muscle and meat

Freely filtered across glomerulus and 15% from tubular secretion by proximal tubule

Question 6

What is the formula for creatine clearance?

Answer 6

Urine creatine concentration x Volume / Plasma creatine concentration

Question 7

What are the limitations of using creatine clearance?

Answer 7

• Incomplete urine collection

- Increased creatine secretion from tubule in renal impairment

Question 8

If GFR is low, what will the level of creatine be?

What is the shape of the curve of creatine against GFR?

Answer 8

Creatine high

Exponential (L shape)

Question 9

Who doesnt glomerular filtration rate work in?

Answer 9

• Children
• Amputees
• Pregnancy

Question 10

Describe stage 1 and stage 2 of chronic kidney disease (CKD)

Answer 10

1 - GFR 90+, normal function, may have structural abnormalities, observe and control BP
2 - GFR 60-89, mildly reduced function, observe and control BP and address risk factors

Question 11

Describe Stage 3 CKD

Answer 11

• GFR 30-59
• Pt asymptomatic
• Creatine marginally raised
• Tend to retain solutes, become hypertensive
• Reduced vit D and calcium
• Reduced Epo, become anaemic
• Observe, BP control and modify drug doses, avoid nephrotoxins

Question 12

Describe Stage 4 CKD

Answer 12

• GFR 15-29
• Creatine 250-600umol/L
• Tired, pale, non-specifically unwell
• Need dietary restriction, phosphate binders, vit D and erythropoeitin
• Usually need anti-hypertensive drugs and diuretics

Question 13

Describe Stage 5 CKD

Answer 13

• GFR <15
• Creatine >700
• End stage renal failure requiring dialysis if GFR<5mls/min or creatine >900
• Pale, tired, unwell
• Anorexic, nausea, vomiting, uraemic fetor, itch
• Confusion
• Fluid retention, oedema, congestive cardiac failure

Question 14

What condition can cause chronic renal failure?

Answer 14

Diabetes (affects small blood vessels)

Question 15

Give examples of drugs in CRF pts:

a) that are renally excreted so may accumulate
b) that have an altered protein binding
c) that are nephrotoxic so worsen renal function

Answer 15

a) Opiates
b) Increased protein binding = basic drugs e.g. lignocaine. Decreased protein binding = acidic drugs e.g. Phenytoin
c) NSAIDS, Gentamicin

Question 16

What are the effects of uraemia on the haematology of CKF pts?

Answer 16

• Prolonged bleeding time
• Normal platelet count but disturbed platelet function
• Increased bruising
• Check pt not on aspirin or clopidogrel

Question 17

How is bleeding time improved in CKF pt with uraemia?

Answer 17

Dialysis or increased haematocrit (with Erythropoeitin)

Question 18

Name 4 effects of chronic renal failure

Answer 18

• Pulmonary and Peripheral oedema (due to salt and water retention)
• Restless Leg syndrome - cramps, tremors and twitches
• Hormonal imbalance
• Increased cardiac instability (severe metabolic acidosis, hyperkalaemia and hypocalcaemia)

Question 19

What is the definition of acidaemia?

Answer 19

A pH of <7.2 (HCO3- <16mmol/L) that impacts cellular and cardiac function

Question 20

What medical intervention can offer a bridge in pts with acidaemia until dialysis is available?

Answer 20

Sodium bicarbonate

Question 21

What are additional causes of acidaemia?

Answer 21

• Lactic acidosis
• DKA
• Poisoning

Question 22

What happens if a patient misses dialysis session?

Answer 22

Lungs can fill with fluid and become breathless - pulmonary oedema

Question 23

In what circumstance should anticoagulation be avoided in dialysis?

Answer 23

Pericardial effusion as it will reduce the risk of pericardial bleeding

Question 24

For Haemodialysis

a) How often?
b) Where is the fistula connected?
c) What anticoagulation is used?
d) What does it achieve?

Answer 24

a) 4 hrs 3 x week
b) Tunneled intrajugular neckline or arm arteriovenous (Brachial AV)
c) Heparin
d) Fluid removal and biochemical correction

Question 25

What are the issues with AV fistula?

Answer 25

Haematoma and Infection

Question 26

What are the 2 types of vascular access lines for dialysis?

Answer 26

Temporary line 'Vascath' (high infection risk, internal jugular, lasts 1-2 yrs) Tunelled lines 'Tesid' (cuff reduces infection)

Question 27

What are the pros and cons of continuous ambulatory dialysis (CAPD)?

Answer 27

``` + Gentle, good biochemical control + No anticoagulation - Weight gain with glucose as osmotic agent - Peritonitis - Peritoneal membrane failure over time ```

Question 28

What are the complications of uraemia and dialysis?

Answer 28

- Hypotension - Cramp - Anaemia - Vascular calcification - Increased risk of heart disaes - Amyloidosis as a consequence of beta-2-microglobulin accumulation

Question 29

Who does not require antibiotic prophylaxis?

Answer 29

- Immunosupressed transplant patients - Dialysis patients - CRF patients with no valve/endocarditis risk - CAPD or tunelled central line patients

Question 30

Who does require antibiotic prophylaxis? What cover is given?

Answer 30

- Haemodialysis patients with a prosthetic valve or other endocarditis risk - Amoxicillin 3g 1 hr before procedure or IV Vancomycin or Gentamycin for dialysis pts, Clindamycin for penicillin allergies

Question 31

What rare inherited syndrome is associated with kidney disease and also causes bifid tongue?

Answer 31

Orofacial digital syndrome

Question 32

What drugs that are used in immunosupression for renal transplants cause gingival hypertrophy?

Answer 32

- Tacrolimus/Fk506 and Cyclosporin A/Neoral

Question 33

What drugs that are used in immunosupression for renal transplants cause hyperlipidaemia, delayed wound healing and stomitis?

Answer 33

Sirolimus or Rapamycin

Question 34

Which immunosuppressive drugs used in renal transplant pts inhibit purine synthesis?

Answer 34

Azathioprine and mycophenolate mofetil (MMF)

Question 35

What is the MOA of cyclosporin and tacrolimus?

Answer 35

Calcineurin inhibitor which blocks activation of T cells and so of cytokines such as IL2

Question 36

What is a clinical feature of nephrotic syndrome?

Answer 36

Bilateral periorbital oedema

Question 37

What is nephrotic syndrome?

Answer 37

- Massive proteinuria with hypoalbuminaemia | - Leaky kidneys so low levels of protein in intravascular compartment

Question 38

What are the clinical implications of treating a patient with nephrotic syndrome?

Answer 38

- Taking long term steroids - Electrolyte disturbances and steroid treatment lead to risk of infection - Pts more likely to have cardiovascular disorders

Question 39

What is the most common cause of end stage renal failure?

Answer 39

Diabetic nephropathy

Question 40

What should you be thinking of if treating a patient with a renal transplant?

Answer 40

- Steroid cover for certain procedures that are physiologically stressful - No antibiotic cover but bear in mind for M.O.S - Predisposition to infections: oral candidosis, herpes simplex, zoster virus - in some cases low dose aciclovir given - Greatly increased chance of malignant disease e.g. skin cancer and lymphomas as immunosuppressed

Question 41

Describe the feedback loop that makes renal osteodystrophy a universal feature of CKD

Answer 41

Increase in plasma phosphate levels Supression of plasma calcium Elevated parathyroid hormone levels (PTH) Calcium taken out of bones Calcium further compromised by disruption in Vit D metabolism

Question 42

Renal osteodystrophy in CKD pts can also be secondary to use of which drug?

Answer 42

Steroid therapy (osteoporosis and bisphosphonate therapy)

Question 43

Why does anaemia occur in CKD pts?

Answer 43

Failure of production of erythropoietin by kidneys Renal loss of RBCs Marrow fibrosis Increased RBC fragility with early destruction Reduced platelet count and function

Question 44

What are the features of anaemia of chronic disease seen in CKD pts?

Answer 44

- Normochromic - Normocytic - Hb 70g/L (normal is 180g/L) - Reduced platelet count/functioning

Question 45

When is the optimal time for dental treatment after dialysis?

Answer 45

1 day - heparin worn off and renal function optimal

Question 46

Why might there be problems with haemostasis in a CKD pt?

Answer 46

- Impaired platelet count and adhesion - Decreased von Willebrands factor - Decreased thromboxane - Prostacyclin levels increased (vasodilation) - Heparinisation (heparin wears off quickly)

Question 47

What may you notice about a CKD pt on examination?

Answer 47

E/O - Fistula, Oedema, Steroid facies (moon face), swelling of major salivary glands/sialosis (dialysis pts) I/O - Increased incidence of ulceration and infections, gingival hyperplasia (cyclosporin), palatal and buccal keratosis sometimes seen (xerostomia)

Question 48

What would you notice O/E of a child with CKD?

Answer 48

- Decreased growth | - Delayed tooth eruption and enamel hyperplasia (due to metabolic disturbances)

Question 49

Which drugs should you avoid in CKD pts?

Answer 49

- Tetracyclines (other than doxycycline) - NSAIDs (unless mild) - Gentamycin (nephrotoxic) - If had a transplant and taking cyclosporin Erythromycin

Question 50

Which drugs should you reduce dose of in CKD pts?

Answer 50

Aciclovir, Amoxicillin, Ampicillinm Cefalexin, Erythromycin

Question 51

What is acute kidney injury?

Answer 51

Medical emergency, potassium rises to a dangerous level that leads to cardiac arrythmias and cardiac arrest. May be seen in hypovolaemia (if bled a lot)

Question 52

How can potassium level be lowered in acute kidney injury?

Answer 52

- Calcium resonium (rectal) | - Glucose and insulin IV infusion - take potassium out of bloodstream