Evaluation of Renal function - More Flashcards
How does serum creatinine work?
What is it affected by?
It is released from muscles and excreted by the kidney
Increased levels suggests low GFR
- Affected by muscle mass/diet
- Trimethroprim increases
- Secreted by tubules so can overestimate GFR
How does serum urea work?
What is it affected by?
It is secreted by the kidneys and an increase suggest kidney injury
- Increased in dehydration
- Made my liver so may be low in liver disease
How does creatine clearance work?
Looks at serum levels compared to urine levels but needs 24 hour urine samples and blood tests
How can urine osmolality be used to analyse kidney function?
It should be acidic as acidic toxins are excrted, if it is alkaline it suggests kidney insult.
Urine osmolality should be lower than plasma (secrete excess water) if not not it suggests SIADH
How can plasma electrolytes be used to analyse kidney function?
High K+ suggests a reduction in kidney function as it is normally excreted
Low bicarb suggests a reduction in kidney function as not being excreted
When would you do an abdo X ray?
?Stones
?Renal size
When would you do a renal US?
Kidney size/shape/poition
?Stones, obstruction
When would you do a doppler US?
?renovascular disease
When would you do CT urogram?
?stones/masses
Tumour staging
When would you do angiography?
?Renal stenosis
When would you do a biopsy?
?Parynchymal disease
When may you do an isotope scan?
?GFR
