50) Overview of renal diseases

Question 1

What is the tempo of presentation of a disease?

Answer 1

• How quickly the disease occurs after a catastrophic event

Question 2

What are the different tempos of presentation?

Answer 2

• Acute: Rapid changes in kidney function over a few days
• Chronic: Changes in kidney function over years
• Acute on chronic: Chronic diseases that are normally accelerated

Question 3

What is used to measure kidney function?

Answer 3

• Volume of fluid filtered from the glomerulus in a specified amount of time

Question 4

How is GFR measured ?

Answer 4

• Blood tests
• Urine output tests
• Elimination of radioisotopes

Question 5

How are people diagnosed using creatinine?

Answer 5

• Based on the level of creatinine and urine output patients are put into different stages
• Stage 1 has the lowest creatinine and stage 3 has the highest level of creatinine
• Patients at stage 2 and 3 have a higher mortality rate than other patients

Question 6

What are the different sub-classes of the causes of acute renal failure?

Answer 6

• Pre-renal causes: To do with perfusion
• Intrinsic renal causes: A disease has lead to acute renal failure
• Post renal cause: Obstructions

Question 7

What are the different pre-renal causes of acute renal failure?

Answer 7

• Hypovolaemia: E.g. haemorrhage and volume depletion
• Hypotension: E.g. Cardiogenic shock and Septic shock
• Renal hypoperfusion/vasoconstriction

Question 8

What are the different intrinsic renal causes of acute renal failure?

Answer 8

• Vascular
• Interstitial
• Glomerular
• Tubular

Question 9

What are the risk factors for decline of kidney function?

Answer 9

• Diabetes
• Hypertension
• Cardiovascular diseases
• Proteinuria
• Acute Kidney Infection
• Smoking
• Ethnicity
• NSAIDs
• Obesity
• Untreated urinary outflow tract obstruction

Question 10

What happens in a diabetic nephron?

Answer 10

• There is high glucose levels and so there is increased Na+ and glucose filtration
• The body tries to correct this through SGLT-2 transporters
• As a result there is a decrease in Na+ in the tubules
• This causes the kidneys to filter more in order to counteract decreased Na+ by vasodilating efferent arterioles
• Overall this results in a pressure effect across the glomerulus, oxidative stress (caused by high sugar levels) and the efferent and afferent arterioles have to deal with increased stress
• Ultimately this causes a cycle of damage including scarring and progressive renal function decline

Question 11

When is dialysis not used?

Answer 11

• Unacceptable impact on quality of life
• Patient choice
• Imminent death
• May not increase lifespan

Question 12

What concepts does dialysis rely on?

Answer 12

• Diffusion: Occurs when there is a difference in solute concentration on either side of the membrane
• Convection: Movement of solute in association with water (called solute drag)

Question 13

How does dialysis work?

Answer 13

• Blood is taken from a patient and thinned.
• It then passes down one side of a highly permeable membrane in a counter current system to maintain a concentration gradient
• Water and solutes pass across the membrane into and out of the dialysate as the blood is filtered of any harmful substances and toxins

Question 14

What are the different types of donors for transplantation?

Answer 14

• Live donors: They can be related, unrelated or altruistic (complete strangers)
• Deceased donors: Donation can come after brain death (DBD) or after circulatory death (DCD)