Renal Failure Flashcards
What parameter do you use to define the function of the kidney?
GFR
What parameter provides a clinical representation of GFR?
Plasma creatinine
What is the normal range for plasma creatinine?
50-120uM/L
Is ARF always symptomatic?
No, sometimes asymptomatic
What level of urine output per day indicates renal failure?
<500 mL
What can make urea high?
High protein diet
Bleeding into gut > more protein absorbed
Catabolic states (eg infection)
What can make plasma urea low?
Malnutrition
Liver Disease
Is creatinine of 110uM/L in an frail old lady ok?
No, should be on the lower end of the range give her low muscle mass
Why isn’t urine urea a good marker of GFR?
Because it is dependent on other variables
T/F Being obese is a risk factor for renal failure?
False
What are two risk factors for acute renal failure?
>60 years old
Pre-existing renal disease
What systemic perfusion pressure must be maintained for proper GFR?
>70mmHg
Below what glomerular hydrostatic pressure will ARF occur?
<45mmHg
T/F NSAIDs can cause pre-renal ARF
True, block prostaglandins required for afferent arteriole dilation
How do ACE inhibitors effect GFR?
Angiotensin is required for constriction of efferent arteriole - knocking that out causes a drop in GFR
What is the most accurate measure of daily fluid balance?
Daily body weight measurement
Why do people on diets lose water weight?
Aldosterone drops and Na and water retention falls
What is the most common intra-renal cause of AFR?
Acute tubular necrosis
Why does diuresis (increase/excessive production of urine) sometimes occur after acute tubular necrosis?
Filtration and secretion returns but reabsorption doesn’t return to full function and lots of urine is excreted
What are 4 causes of post-renal ARF?
Stones
Clots
Tumours
Fibrosis
Which of these can cause anuria?
Glomerulonephritis
Renal artery occlusion
Prostatic malignancy
Interstitial nephritis
Renal artery occlusion
Prostatic malignancy
Glomerulonephritis
What are some short term consequences of ARF?
Acidosis
Sodium and Water retention
T/F Chronic renal failure has reversible loss of renal function
False, it’s irreversible loss
What happens to the remaining nephrons as other die off during ageing?
They hypertrophy
What is glomerular hyperfiltration?
Compensation in other nephrons due to loss of nephrons
What are the consequences of glomerular hyperfiltration?
Loss of functional reverse
Glomerular hypertension
Further damage and glomerulosclerosis
What is glomerulosclerosis?
Fibrosis and scarring of the nephrons due to hypertension and excess filtration
What does uremia in the context of chronic renal failure mean?
Build of toxins (predominantly urea) due to loss of kidney function
What are some common causes of CRF?
Diabetes
High BP
chronic glomerulonephritis
Cystic disease
What is polyuria?
Passing lots of dilute urine
