Acute and Chronic renal Failure 1

Question 1

What is an AKI?

Answer 1

A potentially reversible abrupt decline in GFR with treatment targeted at diagnosis and reversal of disease.

Question 2

What is CKD?

Answer 2

An irreversible longstanding decline in GFR with treatment aimed at prevention of complications and progression. (>3 months)

Question 3

What is acute failure of kidneys?

Answer 3

A rapid reduction in kidney function, leading to an inability to maintain electrolyte, acid-base and fluid homeostasis.

Question 4

Is an AKI an emergency?

Answer 4

Yes- immediate referral for management in nephrology

Question 5

What are the stages of an AKI?

Answer 5

AKI Stage 1: Increase in sCr by ≥26 µmol/L, or by 1.5 to 1.9x the reference sCr

AKI Stage 2: Increase in sCr by 2.0 to 2.9x the reference sCr

AKI Stage 3: Increase in sCr by ≥3x the reference sCr, or increase by ≥354 µmol/L

Question 6

What are the types of AKI?

Answer 6

Pre renal

Renal

Post Renal

Question 7

What is a pre renal AKI?

Answer 7

Reduced tissue perfusion/ local ischaemia

NO structural abnormality

Question 8

What is a normal response to reduced circulating volume?

Answer 8

Activation of central baroceptors activates RAS and there is a release of vasopressin and sympathetic system which causes vasoconstriction, increased cardiac output and renal sodium retention.

Question 9

What are the causes of pre renal AKI?

Answer 9

True volume depletion
Hypotension
Oedematous states
Selective renal ischaemia
Drugs affecting glomerular blood flow

Renal artery stenosis

Question 10

Which class of drugs may commonly predispose patients to developing pre-renal AKI?

Answer 10

ACEi

Question 11

How do these drugs cuase pre renal AKI:
NSAIDS
ACEi/ARBs
Calcineurin inhibitors
Diuretics

Answer 11

NSAIDs - decrease afferent arteriolar dilatation
Calcineurin inhibitors - decrease afferent arteriolar dilatation
ACEi or ARBs - decrease efferent arteriolar constriction
Diuretics – affect tubular function, decrease preload

Question 12

How can AKI lead to ATN?

Answer 12

Pre-Renal AKI is not associated with structural renal damage and responds immediately to restoration of circulating volume

Prolonged insult leads to ischaemic injury

Acute Tubular Necrosis does not respond to restoration of circulating volume

Question 13

What is the hallmark of post renal AKI?

Answer 13

Physical obstruction to urine flow.

Question 14

What may cause post renal AKI?

Answer 14

(Intra-renal obstruction)
Ureteric obstruction (bilateral)
Prostatic / Urethral obstruction
Blocked urinary catheter

Question 15

What is the pathophysiology of obstructive uropathy?

Answer 15

GFR is dependent on hydraulic pressure gradient
Obstruction results in increased tubular pressure
Immediate decline in GFR

Question 16

How do you recover from obstructive uropathy?

Answer 16

Immediate relief of obstruction restores GFR fully, with no structural damage

Question 17

What can prolonged obstruction cause?

Answer 17

Glomerular ischaemia
Tubular damage
Long term interstitial scarring

Question 18

What is are the types of intrinsic AKI?

Answer 18

Vascular Disease e.g. vasculitis

Glomerular Disease e.g. glomerulonephritis

Tubular Disease e.g. ATN

Interstitial Disease e.g. analgesic nephropathy

Question 19

How does direct tubular injury occur?

Answer 19

Ischaemia
Endogenous toxins (Myoglobin, Igs)
Exogenous toxins (Aminoglycosides, amphotericin, acyclovir)

Question 20

Patient has new onset AKI, haematuria and massive bruising. What is the likely diagnosis?

Answer 20

Rhabdomyolysis (Myoglobin is toxic)

Question 21

A 40 year old female presents with a papular coalescing rash and AKI is diagnosed. What is the most likely cause of her renal failure from the following list?

Answer 21

Systemic Vasculitis

Question 22

What are common mechanisms of renal injury?

Answer 22

1. Immune dysfunction (Renal inflammation):
   a. Glomerulonephritis
   b. Vasculitis
2. Infiltration/ abnormal protein deposition:
   a. Amyloidosis
   b. Lymphoma
   c. Myeloma-related renal disease

Question 23

What are the important causes?

Answer 23

Pre-renal

ATN

Question 24

What are the non fatal outcomes of AKI?

Answer 24

Complete or partial recovery of renal function

Discharged with increasing creatinine

Discharged with a requirement for dialysis

Question 25

How do acute wounds heal?

Answer 25

Haemostasis Inflammation Proliferation Remodeling

Question 26

What pathology stops renal resolution after an AKI?

Answer 26

Imbalance of scarring and remodelling Replacement of renal tissue by scar tissue in chronic disease

Question 27

What is the process of getting CKD?

Answer 27

Increased Risk Early Damage Reduced GFR Renal Failure Death

Question 28

What are the stages of CKD?

Answer 28

1, Kidney damage with normal GFR, >90, 3.3 % 2, Mild GFR, 60-89, 3 % 3, Moderate GFR, 30-59, 4.3 % 4, Severe GFR, 15-29, 0.2 % 5, End-stage kidney failure, GFR <15 or dialysis, 0.2 %

Question 29

What are the causes of CKD?

Answer 29

``` Diabetes Atherosclerotic renal disease Hypertension Chronic Glomerulonephritis Infective or obstructive uropathy Polycystic kidney disease ```

Question 30

What are the functions of the kidney?

Answer 30

Excretion of water-soluble waste Water balance Electrolyte balance Acid-base homeostasis Endocrine functions (EPO, RAS, Vit D)

Question 31

What are the consequences of CKD?

Answer 31

Progressive loss of homeostatic function (acidosis and hyperkalaemia) Progressive failure of hormonal function (Anaemia, renal bone disease) Cardiovascular disease (vascular calcification, uraemic cardiomyopathy) Uraemia and death

Question 32

What does renal acidosis cause?

Answer 32

Muscle and protein degradation Osteopenia due to mobilization of bone calcium Cardiac dysfunction

Question 33

What is the treatment of renal acidosis?

Answer 33

NaHCO3, PO

Question 34

What is potassium used for?

Answer 34

Major intracellular cation Membrane depolarisation Cardiac function Muscle function

Question 35

What medications can cause hyperkalaemia?

Answer 35

ACEi Spirinolactone Potassium sparing diuretics

Question 36

What is anaemia of chronic renal disease?

Answer 36

Normochromic, normocytic anaemia Usually noted when GFR<30mL/min (Loss of EPO cells)

Question 37

What are the ESAs (Erythropoiesis- stimulating agents)?

Answer 37

``` Erythropoietin alfa (Eprex) Erythropoietin beta (NeoRecormon) Darbopoietin (Aranesp) ```

Question 38

Your patient with CKD has been started on an ESA but does not respond. What could be the cause?

Answer 38

``` TB Malignancy (Chronic Disease) B12/ Folate/ IDA Hyper-parathyroidism ```

Question 39

What are the renal bone diseases?

Answer 39

Osteitis fibrosa Osteomalacia Adynamic bone disease Mixed osteodystrophy

Question 40

What is osteitis fibrosa?

Answer 40

Osteoclastic resorption of calcified bone and replacement by fibrous tissue Comes with hyperparathyroidism

Question 41

What is osteomalacia?

Answer 41

Insufficient mineralisation of bone osteoid

Question 42

What is adynamic bone disease?

Answer 42

Excessive suppression of PTH results in low turnover and reduced osteoid

Question 43

What is the treatment of renal bone disease?

Answer 43

Phosphate control: dietary, phosphate binders Vit D receptor activators: 1-alpha calcidol, paricalcitol Direct PTH suppression: Cinacalcet

Question 44

What is associated with atherosclerosis?

Answer 44

Cholesterol Hypertension

Question 45

What are the 3 phases of uraemic cardiomyopathy?

Answer 45

Left ventricle (LV) hypertrophy LV dilatation LV dysfunction

Question 46

What are relative contraindications to renal transplant?

Answer 46

Conditions: Untreated coronary artery disease, HIV, Chronic Hep B/C Age >65 years Previous Malignancy Obesity/ Co morbidity

Question 47

What are absolute contraindications to renal transplant?

Answer 47

Untreated malignancy Active infection Untreated HIV infection or AIDS any condition where life expectancy is under two years.

Question 48

What two measures do we use to define acute kidney injury?

Answer 48

Creatinine and Urine output

Question 49

How is AKI defined using creatinine and urine output?

Answer 49

Stage 1: 1.5–1.9 times baseline OR ⩾0.3 mg/dl (⩾26.5 μmol/l) increase UO = <0.5 ml/kg/h for 6–12 hours Stage 2: 2.0–2.9 times baseline UO = <0.5 ml/kg/h for ⩾12 hours Stage 3: 3.0 times baseline OR Increase in serum creatinine to ⩾4.0 mg/dl (⩾353.6 μmol/l)* UO = <0.3 ml/kg/h for ⩾24 hours OR Anuria for ⩾12 hours *OR Initiation of renal replacement therapy OR, In patients <18 years, decrease in eGFR to <35 ml/min per 1.73 m2

Question 50

What measures aid prognosis in CKD?

Answer 50

eGFR | ACR (Albumin-Creatinine Ration) in the urine

Question 51

What foods can cause hyperkalaemia in CKD?

Answer 51

Tomatoes Chocolate Dried fruits DIET RESTRICTION IS IMPORTANT