overview of renal diseases Flashcards
What are the functions of the kidney?
- BP control
- EPO production (RBC production)
- acid base balance
- Vit D activation
- excretes waste substances
- regulates minerals in extracellular fluid
where is Na+ mostly reabsorbed?
PCT
where is K+ mostly reabsorped/secreted?
DCT
which part of the nephron is a modified capillary bed?
glomerulus
how do we measure kidney function?
Blood tests
-Creatinine (a metabolic by-product of skeletal muscle, as GFR falls you secrete less creatinine)
-Formulae, estimate GFR using the Cockcroft gault equation which takes into account the age, gender and weight, or the
MDRD equation (the modification of diet in renal disease)
Urine output
Elimination of radioisotypes
most accurate way = inulin, but it is expensive
give 2 situations where you would need to estimate GFR:
Kidney donor
-if you take one kidney away, you need to work out GFR to see if there is enough function in the other kidney to allow the body to function properly, and to see if the kidney is a good enough donor
Cancer patient using chemotherapeutic drugs
-very narrow therapeutic index, work out GFR so you can work out the dosing, based on how they are cleared from the kidney
what indicates kidney damage
presence of blood/proteins in the urine
Presentations of kidney disease
“Renal syndromes”
- Nephritic syndrome: inflammatory condition in the glomerulus, person has RBCs in the urine, they become hypertensive and their GFR falls because arterioles get damaged, leading to kidney failure
- Nephrotic syndrome: glomerular filtrate becomes very leaky, lots of protein in the urine which lowers serum albumin and lowers the oncotic pressure, so fluid leaks out into the periphery - peripheral odema
- Haematuria – blood in the urine due to bleeding anywhere in the urinary tract (due to kidney stones, infection)
- Acute kidney injury – kidney was working well and suddenly something happened and it doesn’t work well
- Chronic kidney disease – chronic decrease in GFR - this worsens over time
Patients can present with overlap between all the symptoms
nephritic syndrome can present itself in which diseases?
Vasculitis
Lupus
Bacterial endocarditis
IgA nephropathy
nephrotic syndrome can present itself in which diseases?
Amyloidosis
Membranous nephropathy
diabetes causes
chronic damage to the kidney due to high blood sugar
what happens in cardiogenic shock
the heart cannot pump enough blood to meet body’s need.
if the kidneys are not functioning properly, how will that affect creatinine levels?
serum creatinine levels will increase as creatinine will accumulate in the blood
how does serum creatinine increase?
exponentially
why might serum creatinine levels increase?
not perfusing the kidney for a period
- can happen due to a surgery, or if the person has been severely bleeding
- dried out through vomiting or diarrhea, because this would lead to increased ADH levels and decreased urine volume