Chemical Pathology Of Renal Disease

Question 1

What are the 2 main functions of kidney

Answer 1

Excretion and haemostasis

Endocrine function

Question 2

What does the excretion and haemostasis function of the kidney involve

Answer 2

Waste products of metabolism
Fluid electrolyte balance
Acid base balance
Removal of drugs and toxins

Question 3

What are the endocrine functions of the kidney

Answer 3

Renin angiotensin aldosterone system
Erythropoietin production
Hydroxylation of vitamin d

Question 4

When is the excretion and homeostasisis ditrupted

Answer 4

Early AKI

CKD

Question 5

When is the endocrine distrubted

Answer 5

CKD

Question 6

What is the definition of AKI

Answer 6

Rise in creatinine and low urine output

Question 7

What are the stages of AKI

Answer 7

Stage 1 to stage 3

Question 8

What is stage 1 AKI

Answer 8

Creatinine rise 1.5-1.9 times from baseline and

Less than 0.5ml/kg/h for 6-12 hours

Question 9

What is stage 2 AKI

Answer 9

Creatinine rise 2-2.9 times from baseline and less than 0.5ml/kg/h for more than 12 hours

Question 10

What is stage 3 AKI

Answer 10

Creatinine rise more than 3 time from baseline or rise to 353.6 or need for renal replacement therapy irrespective of serum creatinine and less than 0.3ml/kg/h for more than 24 hours or anuria for more than 12 hours

Question 11

What happens to mortality in AKI as the stage increases

Answer 11

Increases with increased stage

Question 12

What are the categorical causes of AKI

Answer 12

Renal underperfusion
Intrinsic renal damage
Post renal AKI

Question 13

What are the common causes of renal underperfusion

Answer 13

Hypovolaemia- haemmorhage, dehydration
Sepsis: vasodilation
Renal artery stenosis
Pump failure: heart failure

Question 14

What are the common causes of intrinsic renal damage

Answer 14

Ischaemia
Nephrotoxins: drugs, posison, myoglobulin, paraproteins
Infection: pyelonephritis
Trauma
Early stage of inflammation causes of chronic kidney disease

Question 15

What are the causes of post renal aki

Answer 15

Stones
Tumours
Prostatic hypertrophy

Question 16

What is the common cause of AKI

Answer 16

Underperfusion

Question 17

When there is hypovaolemia, sepsis or renal artery stenosis i.e renal underperfusion how does it develop into AKI

Answer 17

Underperfusion causes pre renal failure
Prolonged renal underperfusion causes damage to the kidney resulting in acute tubular necrosis
Acute tubular necrosis results in intrinsic renal failure

Question 18

How can we recognise pre-renal and intrinsic renal damage AKI

Answer 18

By looking are:
Urine volume 
Urine: plama osmolality
Urine sodium concentration
Plasma sodium
Serum elevation of urea vs creatinine

Question 19

What is the urine volume in pre renal and intrinsic renal damage

Answer 19

Pre renal: low- blood it not being delivered to kidney

Intrinsic renal damage: high- kidney cant absorb water and electroylytes so there is high ouput

Question 20

What is the urine: plasma osmolality in pre renal and intrinsic renal damage

Answer 20

Pre renal: more than 2:1 (high in urine)

Intrinsic renal damage: less than 1:1

Question 21

What is the urine sodium concentration in pre-renal and intrinsic renal damage

Answer 21

Pre renal: urine sodium concentration is low because aldosterone is switched on which promotes sodium retention to promote water retention

Intrinsic renal damage: high because the kidney cant absorbed sodium due to the intrinsic problems in the tubules

Question 22

What is the plasma sodium in pre-renal and intrinsic damage

Answer 22

Pre renal: high

Intrinsic: low

Question 23

What is the serum elevation of urea vs creatinine in pre renal and intrinsic renal damage

Answer 23

Pre renal: urea is more than creatinine

Intrinsic: urea and creatinine are the same

Question 24

Who do we give fluid replacement to, pre-renal or intrinsic damage

Answer 24

Pre renal because the kidney is underperfused

Question 25

Why do we not give fluid replcement in intrinic damage

Answer 25

Giving fluid will mean the patient cant pee it out as the kidney is damage so this will elad to fluid overload

Question 26

In AKI do we see endocrine problems

Answer 26

No

Question 27

Which process in AKi is lost first

Answer 27

Excretion and homeostasis

Question 28

What do we see in AKI

Answer 28

High potassium High acidosis- from acidic waste Retained nitrogenous waste Hyponatraemia (due to fluid overload and fluid retention

Question 29

What symptomd foes hyperkalaemic metabolic acidosis lead to

Answer 29

Malasie | Nausea

Question 30

What is the management of AKI

Answer 30

1. Identifying if pre-renal, intrinsic renal or post renal causes 2. Identify the cause- stop ARBS, ACEi and NSAIDs, correct fluid, electroylyte and acid base abnormality, restore renal perfusion

Question 31

What is chronic kidney disease

Answer 31

``` Diabetes Hypertension Polycytstic kidney disease Recurrent pyelonephritis Glomerulonephritis Intersitital nephritis Multi system disease Drugs ```

Question 32

How to we monitor CKD

Answer 32

24 hour urine collection for protein Estimated egfr - in early stages Creatinine- in late stages Albumine creatinine ratio

Question 33

Why do we look at egfr in early and creatinine in late stages

Answer 33

In early stage: creatinine is normal | In late stages: efgr is normal

Question 34

What are the stages in CKD

Answer 34

Stage 1 to 5

Question 35

What endocrine changes occur in stage 3-4 ckd

Answer 35

Reduced 1 alpha hydroxylation of vitamin d (so you dont get vitamin d to absorb calicum from the diet) this causes hypocalcaemia and secondary hyper parathyroidism (to compensate for low calcium) Reduced erythropoietin production- leads to anaemia Increased cholesterol- increases risk to CVD

Question 36

What changes do you see in stage 4-5 ckd

Answer 36

High phosphate Anemia Acidosis Hyperkalaemia- offset by increased gut losses until late stage

Question 37

What is the water balance in ckd dependent on

Answer 37

Where the damage is

Question 38

How does CKD lead to bone disease

Answer 38

1. When PTH cant correct the calcium it corrects it by bone resportion leading to osteitis fibrosa 2. Lack of calcium alsoe leads to ostoemalacia i.e bone note being buily properly 3. Reduced gfr means you cant get rid of phosphate, phosphate binds to calcium to cause calcium phosphate which deposit to arteris leading to metastatis calcification 4. Reduced gfr also causes metabolic acidosis which casuses dissolved bone buffers that causes bone decay i.e osteoporosis

Question 39

What is the management of stage2-3a CKD

Answer 39

Monitor patients Treat underlying cause eg diabetes Avoid precipitatns of AKI Slow progression by blocking the RRA system with ACEi/ARB is ACR raised

Question 40

What is the management of stage 3b-5 CKD

Answer 40

Correct endocrine abnormality: - give alfacidol (1,25, oh vitamind d) to correct calciuma dn hyperparathyrodisim - erythropoietin to prevent anaemia - low potassium diet - fluid