SUMMARY: how to investigate disorders of renal function W2

Question 1

common clinical investigations for assessment of renal function?

Answer 1

glomerular function - GFR, urinary protein

tubular function - electrolytes, osmolality, urine output, blood gases

Question 2

what does GFR provide/guide

Answer 2

provides assessment of global renal function

guides management in CKD
guides dosing of potentially toxic renally cleared drugs

Question 3

what is a fast cost effective measurement of GFR?

Answer 3

eGFR, most commonly via one-off blood creatinine measurement
(this may be unreliable in certain situations)

Question 4

what is AKI? common cause? how is it detected?

Answer 4

AKI is an abrupt loss of renal function.

most commonly caused by non-renal pathology eg sepsis.

detected by rise in creatinine or reduction in UO (relies on accurate estimate of baseline creatinine)

Question 5

how is renal tubular function assessed

Answer 5

serum/urine electrolytes/osmolality/Na
urine output
blood gas measurement

Question 6

what is renal tubular function essential for

Answer 6

electrolyte, water and acid-base homeostasis

Question 7

what does proteinuria reflect and assess? how is it measured?

Answer 7

reflects damage to glomerulus
assess severity of CKD
measured by lab urine protein or albumin

Question 8

what is dipstick urinalysis used for

Answer 8

used to detect significant proteinuria (avoids need for lab measurement but less sensitive)
also provides quick detection of multiple urinary analytes