Renal disease Flashcards
Normal GFR for adults and elderly
Adults more than 90ml/min
For elderly 60ml/min
Normal creatinine
under 110mcmol/L
Normal potassium range
3.5-5 mmol/L
What cells are in the glomerulus?
Endothelial layer with pores
Glomerular basement membrane
Podocytes
What are the kidney’s functions?
Filtration of waste products Electrolyte homeostasis Hormone production (1,25 calcitriol active vitamin D), erythropoetin Blood pressure control via RAS Acid base homeostasis
What is oliguria?
Low urine output
Where is creatinine produced? Why is this relevant?
Creatinine is made by muscle so can differ in people with different muscle mass
What is the normal GFR
120-130ml/min
rate of plasma clearance by kidneys
What radiomarkers can be used to see GFR accurately?
EDTA
Iothalamate
Iohexol
expensive
takes 2-4hr
IV injection
Name a better marker of eGFR and explain why it’s better
Cystatin - not affected by age, sex or muscle mass
What does the e in GFR stand for?
Estimnated
How do they now calculate eGFR?
Age + creatinine formula
When can eGFR be inaccurate?
AKI
What things can make your urine look red/brown without haematuria?
Rhabdomyolysis
Rifampicin
Food dyes/beetroot
Porphyria
How is proteinuria measured?
Protein to creatinine ratio or albumin creatinine ratio
Normal PCR
20-30
What does acute kidney injury mean?
Rapid decline in renal function over a period of hours or days with accumulation of waste products, potentially life threatening metabolic consequences
With our without a change in urine output
What is the numerical definition of AKI (two different)
Serum creatinine rise by greater than 26umol/L within 48hrs
OR
Serum creatinine rise 1.5 times the reference range which is known or presumed to have occurred within one week
How is AKI defined with regards to urine output?
Urine output of less than 0.5ml/kg for 6 consecutive hours
How many stages of AKI are there?
3 stages
Risk factors for AKI
Age >75yrs Pre-existing CKD (eGFR<50ml/Kg) Previous episode of AKI Debility and dementia HF Liver disease DM Hypotension Sepsis Hypovolaemia Nephrotoxic drugs Continued antihypertensives in hypotension
Acute illness
Major surgery
Name a type of AKI. What is the pathophysiology? What kinds of things lead to this intrinsic AKI?
Acute tubular necrosis is an ‘intrinsic AKI’ where hypoperfusion or injury to the epithelial cells causes the basement membrane to detach and malfunction.
Causes:
Sepsis
Low BP
Nephrotoxic drugs
Pre-renal causes of AKI
Low CO
Hypotension
Renal artery thrombosis
Renal causes of AKI
Acute tubular necrosis Glomerulonephritis Vasculitis Nephrotoxins Contrast Rhabdomyolysis Interstitial nephritis HUS TTP Malignant HTN Myeloma
Renal causes of AKI
Acute tubular necrosis Glomerulonephritis Vasculitis Nephrotoxins Contrast Rhabdomyolysis Interstitial nephritis HUS TTP Malignant HTN Myeloma Goodpasture's sydnrome Lupus
If you have elevated serum creatinine or reduced eGFR, what do you think?
Is it acute or chronic?
Cause?
Treatable?
What are the symptoms of uremia?
Nausea
Vomiting
?
Why might someone on chemo have AKI?
Nausea and vomiting
If there was a pre-renal cause, what would you expect to see in the urine?
No blood or protein
Tubular problem - what would you see in urine?
Minimal blood
Glomerular problem - what would you see in urine?
??
Investigations
Volume status (for ATN)
Urine microscopy and dipstick
Imaging
??????????
What do you need to urgently manage?
Potassium
PO
Acidosis
??????????????????
What ECG changes would you see with hyperkalemia?
High T waves
broad QRS complexes
When do people with end stage chronic kidney disease?
Can be in teenage years due to congenital causes that have been missed, or reflux kidney disease
How many stages of CKD are there?
5
What increases the risk of death with CKD?
Albuminurea
Causes
Elderly ApoLone gene? Diabetes Chronic glomerulonephritis Vascular diseases Autosomal dominant polycystic disease
Investigations for CKD
Identify cause
Complications of CKD
cardiovascular complications e.g. heart attack and stroke
Calcification
Management of CKD
BP control - ACEi/ARB
Reduce proteinuria
SGLT2 inbhitors
Name an ARB and dose used in CKD
Irbesartan 150-300mg
Name an SGLT2 inhibitor
Gliflozins
What is nephrotic syndrome?
Proteinuria
Oedema
Hypoalbuminia
What counts as proteinuria?
more than 300mg
Cystoscopy looks at what?
bladder
Proteinuria and enphrotic sydnrome suggest?
Always indicates glomerular pathology
Causes of proteinuria
Diabetes Amyloid SLE membranous nephrotpathy minimal change glomerula disease and FSGS
Management
??????????
serum albumin and cholestrol
serum creat/eGFR
glucose, SLE , virology, myelmoa screen, immunology
Management of proteinuria
Control oedema
ACEi/ARB
Treat the cause
Steroids/immunosupression
When do you look at the bladder if someone has haematuria?
only do cystoscopy if over 40 years old
Painful haematuria
urological cause e.g. stones or cancers
Under 40 and no pain
Intrinsic microscopic renal/glomerula cause
?????????????
Alport’s syndrome
IgA nephropathy
