Renal Flashcards
What is the normal glomerular filtration rate?
120ml/hr
What is the normal age-related decline in GFR?
1ml/hr/year
Define renal clearance
The volume of plasma that can be completely cleared of a marker substance in a unit of time
When does clearance equal GFR?
When a substance is not bound to serum proteins, can be freely filtered by the glomerulus, and is not secreted or absorbed by tubular cells
What is the gold standard measure of GFR, and why is it not used?
Inulin. Not used as requires a steady state infusion and difficult to assay
Which substance is used to measure GFR?
Creatinine
What tests can be done on a single urine sample?
Dipstick testing, MC&S, proteinuria quantification (protein to creatinine ratio)
What tests can be done on a 24h urine collection?
Creatinine clearance estimation, electrolyte estimation, assessment of stone forming elements
What does urine microscopy look for?
Crystals, red blood cells, white blood cells, casts, bacteria
What are the signs of glomerulonephritis on urine microscopy?
White blood cells, casts
What are the signs of UTI on urine microscopy?
Red blood cells, white blood cells, bacteria
What is acute kidney injury?
Rise in serum creatinine >26.5 in 48h or to 1.5x baseline in 48h
State 5 indications for emergency dialysis in the setting of acute kidney injury
Pulmonary oedema, refractory hyperkalaemia, metabolic acidosis, uraemic encephalopathy, lithium toxicity
Describe pre-renal acute kidney injury
Reduced renal perfusion with no structural abnormality of the kidney, responds to volume replacement
Describe post-renal acute kidney injury
Obstruction to urinary flow preventing glomerular filtration as this requires a pressure gradient, reversal of flow can cause scarring and permanent renal impairment
Name the four types of renal acute kidney injury
Vascular, glomerular, tubular, interstitial
Describe stage 1 chronic kidney disease
Kidney damage with normal GFR (>90)
State the GFR in stage 2 kidney disease
60-89
State the GFR in stage 3 kidney disease
30-59
State the GFR in stage 4 kidney disease
15-29
State the GFR in stage 5 kidney disease
<15
State the 6 most common causes of chronic kidney disease
Diabetes, atherosclerotic renal disease, hypertension, chronic glomerulonephritis, infective or obstructive uropathy, polycystic kidney disease
Describe the consequences of chronic kidney disease
Progressive acidosis, hyperkalaemia, anaemia, renal osteodystrophy, vascular calcification and atherosclerosis, uraemia (leading to cardiomyopathy and encephalopathy), death
What is required for peritoneal dialysis?
Tenckoff catheter, home dialysis machine
Name two agents commonly used for immunosuppression post-kidney transplant
Tacrolimus, ciclosporin
What is the standard site of kidney transplant?
Right iliac fossa
Name the typical scar left by a kidney transplant
Rutherford Morrison scar (hockey stick scar)
