Week 11: CKD

Question 1

Definition of CKD

Answer 1

> 3 months of abnormal kidney function/ structure

• GFR <60 ml/min/1.73m^2
• ACR >3 mg/mmol

Question 2

Why does CKD cause hypertension

Answer 2

Falling GFR causes the kidneys to increase renin secretion

Question 3

2 main causes of CKD

Answer 3

1. Hypertension

2. Diabetes

Question 4

5 stages of CKD based off GFR (G1-G5)

Answer 4

G1. >90 (normal)
G2. 60-89 (mild)
G3a. 45-59 (mild-moderate)
G3b. 30-44 (moderate-severe)
G4. 15-29 (severe)
G5. <15 (kidney failure)

Question 5

3 modifier stages of CKD based off albuminuria (A1-A3)

Answer 5

A1. <3 micog/dl
A2. 3-2.9 microg/dl
A3. >30 microg/dl

Question 6

In which groups of people might the CKD stage classification not be as accurate

Answer 6

1. Elderly pts
2. Extremes of weight (assumes everyone is 72kg)
3. Advanced stages of CKD
4. Certain ethnic groups

Question 7

Explain the difference in interpreting Albumin: Creatinine Ratio (ACR) vs Protein: Creatinine Ratio (PCR) results

Answer 7

Not all protein in urine is albumin.

Proteinuria without albuminuria could be due to other protein types (eg light chain proteins in myeloma)

–> Look at ACR to define CKD

ACR is the albumin to URINE creatinine ratio

Question 8

What is creatinine

Answer 8

Waste product of muscle metabolism.

Comes from creatine (which is synthesised in liver, stored in muscle)

Question 9

What factors would alter a serum creatinine

Answer 9

1. Muscle mass
2. Muscle catabolism
3. Liver function
4. A high protein meal
5. Trimethoprim (competes with creatinine for same tubular transport)

Question 10

Complications of CKD on electrolytes

Answer 10

1. Hyperkalemia (cannot excrete as much potassium)
2. Hypocalcaemia (less Ca2+ absorbed from diet due to less Vit D)
3. Hyperphosphataemia
4. Hyperparathyroidism

Question 11

Complications of CKD on

blood

Answer 11

1. Anaemia (less production of epo)

2. Uraemia/Azotaemia

Question 12

Complications of CKD on

blood pressure and fluid retention

Answer 12

1. Hypertension
2. Peripheral oedema
3. Pulmonary oedema, pleural effusion, raised JVP

Question 13

Describe the pathophysiology of the impact of CKD on calcium metabolism (when GFR <30)

Answer 13

1. Less Vit D can be activated
2. Less Ca2+ absorbed from diet
3. Hypocalcaemia
4. Hyperparathyroidism
5. PTH causes resorption of calcium from bones –> renal osteodystrophy
6. Increased fractures, bone pain

Question 14

Neuro complications of CKD

Answer 14

1. Cognitive impairment
2. Tremors/ twitching/ seizure (due to low Ca)
3. Neuropathy

Question 15

How are AKI stages modified when someone has CKD

Answer 15

AKI stages remain the same

Question 16

Complications of CKD on blood vessels

Answer 16

Coronary disease

Hyperphosphaetaemia causes deposition of calcium in vessels

-> leads to hypertension and LVH

Question 17

How are AKI stages modified when someone has CKD

Answer 17

AKI stages remain the same

Question 18

Which drug is the most important in slowing progression of renal failure

Answer 18

ACEi/ ARB

-> improves proteinuria and hypertension

Question 19

What drugs reduce CVS risk in CKD

Answer 19

1. ACEi/ ARB

2. Statins

Question 20

Management of blood sugar in CKD

Answer 20

SGLT2 inhibitors

Question 21

Management of reduced kidney function in CKD

Answer 21

1. Dialysis
2. Kidney transplant

No drugs are available to treat progressive fibrosis in kidneys

Question 22

Management of reduced kidney function in CKD

Answer 22

1. Dialysis
2. Kidney transplant

No drugs are available to treat progressive fibrosis in kidneys

Question 23

Management of fluid retention in CKD

Answer 23

1. Diuretics
2. ACEi/ ARB/ CCB
3. Dialysis

Question 24

Management of uraemia in CKD

Answer 24

1. Supportive treatment (treat symptoms)

2. Dialysis

Question 25

Management of acidaemia in CKD

Answer 25

1. Sodium bicarbonate | 2. Dialysis

Question 26

Management of hyper-phosphataemia in CKD

Answer 26

1. Low phosphate diet | 2. Drugs which bind phosphate (eg calcium carbonate)

Question 27

Target HbA1c in CKD

Answer 27

HbA1c <53

Question 28

Target blood pressure in CKD

Answer 28

<140/90

Question 29

Target Hb levels in CKD. What happens if levels are too low/high

Answer 29

10.5-12.5 g/dl <10 = more symptoms, higher mortality >12.5 = improved QoL but higher mortality

Question 30

Management of anaemia in CKD

Answer 30

1. Epo replacement drugs | 2. Iron

Question 31

At what stage of CKD does anaemia tend to occur

Answer 31

Stages 3 and above. If pt is anaemic at earlier stages, check for other causes of anaemia

Question 32

What endocrine abnormalities are risk factors for diabetic nephropathy

Answer 32

1. Poor glycaemic control 2. Longer duration of diabetes 3. Hypertension 4. Dislipidaemia 5. Obesity

Question 33

What kidney function factors are predisposing factors for diabetic nephropathy

Answer 33

1. High albuminuria 2. Glomerular hyperfiltration (GFR>125) 3. Inflammatory disorders affecting kidneys

Question 34

SCREENING: | Pts with which kidney conditions should be screened for CKD

Answer 34

1. AKI 2. Structural renal tract disease 3. Recurrent renal stones 4. Any detection of haematuria

Question 35

SCREENING: | Pts with which cardiac/ vascular conditions should be screened for kidney disease

Answer 35

1. Ischaemic heart disease 2. Chronic heart failure 3. PVD 4. Cerebral vascular disease 5. Hypertension

Question 36

SCREENING: | Pts with which prostatic conditions should be screened for kidney disease

Answer 36

BPH

Question 37

SCREENING: | Pts with which prostatic conditions should be screened for kidney disease

Answer 37

BPH

Question 38

SCREENING: | Pts with which endocrine conditions should be screened for kidney disease

Answer 38

Diabetes

Question 39

SCREENING: | Pts with what Family History should be screened for kidney disease

Answer 39

Family history of 1. End stage CKD (G5 stage) 2. Hereditary kidney disease

Question 40

How does hypertension cause CKD

Answer 40

1. Narrowing of renal arteries 2. Less oxygen delivery to kidney 3. Ischaemic injury to kidney 4. Foam cells slip into glomerulus and secrete TGF-B1 5. TGF-B1 cause mesangial cells to regress to immature state and secrete extracellular matrix 6. Extracellular matrix causes glomerular sclerosis 7. Reduced ability for nephron to filter blood 8. CKD

Question 41

Histological features of diabetic nephropathy

Answer 41

1. Kimmelstiel-Wilson nodule (expanded mesangium) 2. Nodular glomerulosclerosis 3. GBM thickening

Question 42

Which immunoglobulins/ complement proteins may be found on immuno-stain in diabetic nephropathy

Answer 42

1. IgG, IgM | 2. C3, C1q

Question 43

How does high blood sugar lead to nephron damage (3 different pathways) 1. hormone levels 2. vascular 3. VEGF levels

Answer 43

1. Hyperglycaemia --> Increased aldosterone production --> tissue damage 2. Hyperglycaemia --> Excess glucose sticks to proteins in blood --> stiffening and narorwing of efferent arteriole--> hyperfiltration 3. Hyperglycaemia --> increased VEGF expression --> podocyte damage, endothelial injury

Question 44

How does hyperfiltration lead to nephron damage

Answer 44

1. Hyperfiltration 2. Mesangial cells make more matrix 3. Glomerular sclerosis

Question 45

Why does carpal tunnel syndrome occur in CKD

Answer 45

due to beta2 microglobulin related amyloidosis

Question 46

Which electrolyte, if changed, is more likely to suggest a chronic renal failure

Answer 46

Phosphate (takes a while to change)