Normal functions of the kidneys Flashcards Preview

Human Disease > Normal functions of the kidneys > Flashcards

Flashcards in Normal functions of the kidneys Deck (21):
1

What are the 5 functions of the kidneys?
SwwABED

Excretion of salt, water, and waste products of metabolism
Regulate acid - base
Regulate BP
Produce erythropoetin, activates Vit D
Excrete drugs / metabolites

2

How do we measure excretory renal function?

1) PLASMA / SERUM CREATININE - but this is related to muscle mass. It may not be elevated above normal range until 50% GFR lost.
2) ESTIMATED GFR :MDRD FORMULA
3) CREATININE CLEARANCE
4) ISOTOPE GFR

3

How does serum creatinine (Scr) relate to GFR?

If Scr is high but eGFR is low then kidney failure
If Scr high because of high muscle then need high eGFR too

4

What is normal rate of eGFR?

60 - 100 but only need 10 to live so large reserve

5

What is creatinine?

A waste product of muscle metabolism. It will increase or decrease depending on the efficiency of the kidney

6

What does protein in the urine indicate?

Leakage of kidney filters - glomerula disease

7

What are the two types of renal failure?

Acute and chronic:
Acute kidney injury (AKI)
Chronic kidney disease (CKD)

8

What is AKI?

Acute kidney injury - a rapid loss of renal excretory function. Implies reversibility if underlying condition is treated

9

What is CKD?

Chronic kidney disease - slow progressive loss of excretory renal function. Cause often unknown, usually irreversible and so management is aimed at slowing the progression

10

What are the causes of pre renal AKI? (before the kidney)

Salt and water loss (diarrhoea/vomit/diuretics)
Haemorrhage
Hypotension
Renovascular disease

11

What are the causes of renal AKI?

Tubular necrosis
Interstitial nephritis
Acute glomerulonephritis

12

What are the toxic substances that cause AKI?

Antibiotics
Radiographic contrast media
Chemo agents
Rhabdomyolysis
Intravascular haemolysis
Tumour lysis
Solvents
Hepatorenal syndrome

13

What is a hepatonephrotic kidney?

The collecting system dilates, increasing the pressure
Occurs from an obstruction of ureter or bladder

14

What are the causes of post renal AKI? (after the kidney)

Obstruction to outflow from one / both kidneys

15

What are the causes of CKD?

Diabetic nephropathy
Genetic - polycystic kidney disease
Vascular disease
Chronic glomerulonephritis
Chronic outflow urinary obstruction

16

How is CKD classified?

5 stages:
1 = normal kidney funtion with some other evidence of disease
5 = eGFR

17

What are the consequences of renal failure?

Accumulation of K+, urea, creatinine, H+, water,
Deficiency of erythropoetin (anaemia) and Vit D (hyperPTH)
Delayed drug excretion

18

What is renal replacement therapy?

erythropoetin
VIt D
sodium bicarbonate
Dialysis and transplant (to clean blood)
Anticoagulants - heparin, warfarin and aspirin

19

What are the general consequences of immunosuppression?

Infection
Viral transmission with transplant
Malignancy

20

What effects do cyclosporins have?
(anti-rejection drug for transplants)

nephrotoxicity
tremor
hirsuitism
gingival hypertrophy

21

What drug interactions involve cyclosporins?

Cyclosporins +: macrolides, diltiazem, enzyme inhibitors