Renal Function and Kidney Disease

Question 1

Describe the basic unit which makes up the kidney

Answer 1

• Nephron made up of glomerulus and tubules
• Glomeruli filter around 150 litres per day
• Tubules reabsorb most of this filtrate
• Urine excretion usually under 3 litres per day

Question 2

How much of normal cardiac output do kidneys receive?

Answer 2

25%

Question 3

Describe how filtration is achieved in the glomerulus

Answer 3

• Blood pressure progressively reduced from renal artery to glomerular capillaries
• Glomerular pressure provides hydraulic force for filtration

Question 4

Describe the % sodium resorption at different points along the tubules

Answer 4

PCT - 50-60%
TAL - 25-30%
DCT - 5-10%
Collecting Duct - 1-5%

Question 5

How is normal renal function usually measured?

Answer 5

Assay of serum creatinine (biomarker for kidney function)

Question 6

What does eGFR stand for?

Answer 6

Estimated glomerular filtration rate

Question 7

Name 4 things which eGFR is based on

Answer 7

1. Age
2. Gender
3. Ethnicity
4. Serum creatinine

Question 8

What is “normal” GFR?

Answer 8

Around 100 mL/min

Question 9

How many stages are there in chronic kidney disease (CKD)?

Answer 9

5

Question 10

Describe stage 1 CKD

Answer 10

• eGFR = 90+
• Normal kidney function
• With urinary structural abnormalities

Question 11

Describe stage 2 CKD

Answer 11

• eGFR = 60-89
• Mildly reduced kidney function
• With urinary structural abnormalities

Question 12

Describe stage 3 CKD

Answer 12

• eGFR = 30-59
• Moderately reduced kidney function
• With or without urinary structural abnormalities

Question 13

Describe stage 4 CKD

Answer 13

• eGFR = 15-29
• Severely reduced kidney function
• With or without urinary structural abnormalities

Question 14

Describe stage 5 CKD

Answer 14

• eGFR < 15
• Established renal failure
• Very severe or dialysis dependent kidney failure

Question 15

Name 2 reasons kidneys fail

Answer 15

1. Acute Kidney Injury (AKI)

2. Chronic Kidney Disease (CKD)

Question 16

What is the main issue with acute kidney injury?

Answer 16

• A sudden decrease in kidney function needs urgent assessment as it is usually the setting of another illness
• Primary problem needs addressed ASAP

Question 17

Describe the 4 stages in the natural history of AKI

Answer 17

1. Full recover
2. AKI to CKD
3. Acute on chronic kidney disease
4. AKI to ESRD

Question 18

Name 3 things which normal kidney function depends on

Answer 18

1. Perfusion with adequate pressure and oxygen
2. Intact nephrons
3. Free urinary drainage

Question 19

What is the definition of AKI?

Answer 19

A decrease in GFR which occurs within hours to days and is potentially reversible

Question 20

Name 3 types of AKI

Answer 20

Pre-renal - Disordered perfusion of kidney which is structurally normal
Renal - Damage to nephrons often after prolonged pre renal insults
Post-renal - Urinary drainage obstructed

Question 21

Name 3 causes of pre-renal AKI

Answer 21

1. True Volume Depletion
2. Hypotension
3. Oedematous States

Question 22

Name 2 causes of true volume depletion

Answer 22

1. Blood loss

2. Gastrointestinal losses

Question 23

Name 2 causes of hypotension

Answer 23

1. Septic shock

2. Cardiogenic shock

Question 24

Name 2 causes of oedematous states

Answer 24

1. Cardiac failure

2. Liver failure

Question 25

Name 2 major causes of acute tubular necrosis

Answer 25

1. Renal ischaemia followed by reperfusion | 2. Exposure to nephrotoxins

Question 26

Name 3 nephrotoxins

Answer 26

1. Drugs 2. Radiocontrast dye 3. Haem pigments

Question 27

What is the definition of CKD?

Answer 27

A decrease in GFR which occurs over months or years and is usually irreversible

Question 28

Name 4 common causes of CKD

Answer 28

1. Diabetic nephropathy 2. Hypertensive renal vascular disease 3. Glomerulonephritis 4. Polycystic kidney disease

Question 29

What is the inheritance pattern of polycystic kidney disease?

Answer 29

Autosomal dominant trait

Question 30

What is the most common cause for patients starting dialysis?

Answer 30

Diabetes

Question 31

Name 5 major modifiable risk factors of renal disease

Answer 31

1. Diabetes 2. Hypertension 3. Smoking 4. Dyslipidaemia 5. Cardiac disease

Question 32

Name 3 major unmodifiable risk factors of renal disease

Answer 32

1. Age 2. Male > Female 3. Family history

Question 33

What is the principle of dialysis?

Answer 33

Chemical bath which contains appropriate molecules and exchange them with the toxins in the blood

Question 34

Name 2 types of chronic dialysis

Answer 34

1. Haemodialysis | 2. Peritoneal dialysis

Question 35

Describe haemodialysis

Answer 35

- Usually hospital based - Nurse delivered - Three times per week - Very expensive - Restricted to sites with dialysis machines

Question 36

Describe peritoneal dialysis

Answer 36

- Home based - Patient performs dialysis - Daily administration - Uses abdominal cavity - Cheaper

Question 37

How is the blood stream prepared for haemodialysis?

Answer 37

- Internal arteriovenous fistula | - Surgical connection of vein and artery in fistula

Question 38

Describe how a kidney transplant is achieved

Answer 38

- Placed ectopically in iliac fossa - Original kidneys remain in place - Renal vein anastomosis posterior and lateral to artery

Question 39

Describe kidney transplants as an alternative to dialysis

Answer 39

- Better quality of life from patient - Much better survival rate for patients - Much cheaper than dialysis - Life long drug treatment to suppress immune system

Question 40

Describe 4 types of living donors

Answer 40

Living related - Parents, siblings etc Living unrelated - Partner, spouse Paired donation - Pair doesn't match so swap with another pair Paid donation - Illegal

Question 41

What is the most common complication of kidney transplant for dentists?

Answer 41

Immunosuppression

Question 42

Name 2 issues with immunosuppression

Answer 42

1. Infections | 2. Neoplasia

Question 43

Name 3 examples of infections which are complications of immunosuppression

Answer 43

1. Herpes simplex 2. Papillomavirus 3. Candidiasis

Question 44

Name 3 examples of neoplasia which are complications of immunosuppression

Answer 44

1. Squamous cell carcinoma 2. Basal cell carcinoma 3. Non-Hodgkin's lymphoma

Question 45

What is the cause of Non-Hodgkin's lymphoma?

Answer 45

EBV in immunosuppressed patient

Question 46

Describe the presentation of aphthous ulcers

Answer 46

Round, yellow-grey ulcers present on oral mucosa

Question 47

Describe the presentation of Herpes Simplex virus

Answer 47

Multiple erosions and vesicular lesions are present in the mouth

Question 48

Describe the presentation of Herpes Simplex labialis

Answer 48

Grouped vesicles are evident on lower vermilion boarder

Question 49

Describe the presentation of oral candidasis

Answer 49

White papules and plaques are present on the palate and tongue

Question 50

Describe the presentation of squamous cell carcinoma on the lip

Answer 50

Erythematous, crusted nodule on the lip

Question 51

Describe the presentation of nodular basal cell carcinoma

Answer 51

Pearly papule with telangiectasias can be seen

Question 52

Describe the presentation of infiltrative basal cell carcinoma

Answer 52

Present as indented, scar like lesions

Question 53

Describe the presentation of Non-Hodgkin's lymphoma

Answer 53

May present as an intra oral tumour

Question 54

What is a common side effect of cyclosporin and calcium channel blockers when used in combination?

Answer 54

Gingival enlargement

Question 55

Briefly describe oral diseases commonly found in patients suffering from CKD

Answer 55

- Edentulism - Periodontitis - Oral pain is common - Xerostomia