Nephrology Flashcards
Most common electrolyte abnormality in post obstructive diuresis
hypokalaemia
Commonest cause of intrinsic renal failure in hospital
ATN
Urine MCS in AKI: Bland urine sediment
Favours pre-renal/ATN/MM/interstitial renal disease
Urine MCS in AKI: Active urine sediment
Acute GN
Urine MCS in AKI: hyaline/granular/tubular/epithelial casts
ATN
Urine proteinuria > 1g/d (Pr/Cr >0.1) in AKI
suggests glomerular/intrinsic renal disease
Difference in timing of recovery between pre-renal AKI and ATN
Pre-renal AKI resolves in 24-48hr after underlying insulin is treated ATN takes days to weeks due to time for renal tubules to re-generate
Metabolic acidosis in AKI - what HCO3 cut off is an indication for dialysis
HCO3<10
What UEC marker rises first in new anuria
Instantaneous risk in K+ but creatinine takes days
what marker do you dialyse to in pregnant women requiring dialysis
urea - aim <16; may require 6x dialysis/week
Kidney anatomical site
T12 - L3 Retroperitoneal R) kidney lower because it’s pushed lower by the liver
What separates the blood and filtrate in the glomerulus/bowman’s capsule
Endothelium, basement membrane, epithelium
Juxtaglomerular complex location
Between distal convoluted tubule and afferent arterial
What is the juxtaglomerular complex composed of and what do those cells do
Macular dense - in distal convoluted tubules; senses when sodium and chloride are low; in hypotension, the sodium and chloride levels are low and they communicate to the juxtaglomerular cells (facilitated by the extraglomerular mesengial cells) Juxtaglomerular cells- produce renin in response to low sodium/chloride and increases vascular constriction
sphincters in the bladder
internal sphincter (involuntary) external sphincter (voluntary)
where is the micturition centre in the spinal cord
S2-3
What is the micturition centre and how is it regulated
Micturition reflexion causes contraction of the bladder and relaxation of sphincters It is controlled by the pontine storage centre which stops the micturition reflex and pontine micturition centre can allow the micturition reflex to happen
What cells are linked to IgA nephropathy?
Mesangial cells
What cells are linked to Membranous nephropathy
Podocytes
What cells are linked to ANCA assos GN
Endothelial cells
What cells are linked to FSGS
Podocytes
What cells are linked to minimal change
Podocytes
Diagnosis
Fibromuscular dysplasia
“String of beads”
Is renin elevated in unilateral or bilateral renal-artery stenosis hypertension?
Unilateral - but not a specific finding
Management of renal artery stenosis
- Fibromuscular dysplasia - readily treatable with angioplasty (but RAS is mainly caused by atherosclerotic disease)
- Mild to mod - abundant evidence that medical intervention offers no added benefit
- High risk may benefit from intervention
- Bilateral high grade RAS
- Soliatry functioning kidney
- Recurrent APO
- Deterioriating renal function
Tacrolimus Vs cyclosplorin
less rejection
better renal function
increased graft survival
more Diabetes…………….~ 1.3 to 1.5x
What kind of AKI does aminoglycosides cause?
ATN
Aminoglycosides is filtered and taken up by tubular cells (saturable process so single large dose is less toxic)
What is the difference between medullary sponge kidneys and medullary cystic kidneys?
Medullary sponge kidneys
- Often an incidental finding following nephroliathiasis
- Mostly sporatic
- Generally benign
Medullary cystic kidney
- Renal cysts not evidence on imaging normally
- Tubulo-interstitial disorders characterised by:
- Hyperkalaemia, hyperuricaemia, progression to ESRD
- Autosomal dominant inheritance
Autosomal dominant polycystic kidney disease PKD1 vs PKD 2
PKD-1
- Chromosome 16
- Encodes protein polycystin-1
- Earlier age of cysts and ESKD
PKD-2
- Chromosome 3
- Encodes protein polycystin-2
- More indolent
Diagnosis of autosomal dominant polycystic kidney disease
Ultrasound
DNA analysis mainly reserved for people whose offsprings are being considered for transplant donors
What antihypertensive is first line in ADPCKD
ACEI/ARB
Which ADPCKD patients to screen for cerebral aneurysms for?
- Family history of cerebral aneurysm/SAH or CVA
- New onset headache or neurological symptoms or signs
- High risk professions (e.g. : pilot)
- ?repeat screening every 5 years
MOA and use of tolvaptan
- Vasopressin receptor antagonists
- Suppression of vasopressin release reduces second messenger systems (cAMP) identified as promoters of kidney- cyst cell proliferation and luminal fluid secretion
ADPCKD
Diagnostic hallmark of IgA nephropathy
IgA deposits in the glomerular mesangium
Treatment of IgA nephropathy
- Long-term ACE-I or ARB whe proteinuria is >0.5g/d or aim BP <130/80mmHg
- Corticosteroids if persistent proteinuria >1g/d for 3-6 months of optimized supportive care and eGFR >50mL/min
- Add cyclophosphamide in rapidly progressive crescentic IgAN
Membranous GN biopsy findings
- Diffuse thickening of the GBM
- Deposition of IgG and C3 along the GBM
- Immuno complex seen on GBM on EM
Membranous nephropathy management
- Spontaneous remission in up to 20%
- Parial remission in up to 40%
- Treat
- Heavy proteinuria
- Renal dysfunction
- Cyclophosphamide and steroid based regimens currently first line
- Rituximab emerging as 1st line
anti-PLA2R antibody test
HIgh predictivity for primary membranous nephropathy
Can be used to monitor disease activity
Proliferative lupus nephritis induction agents
- Steroids
- IV methylpred pulses
- Cyclophosphamide
- IV less toxic than oral
- Minimise dosing by using monthly for 3-6 months then switching to MMF or aza
- Mycophenolate
- As effective as cyclophosphamide at inducing remission
- Minimises gonadal toxicity (but also cannot conceive on it)
- Rituximab
- Less evidence
- Tacrolimus + Mycophenolate
Lupus nephritis treatment in pregnancy
- Lupus nephritis should be in remission for 6 months prior conception
- MMF should be switched to azathioprine at least 6 weeks before conception is attempted
- Cyclosplorine and tacrolimus can also be used during pregnancy
Indications for plasma exchange in pauci-immune RPGN
- Severe renal failure
- Concurrent anti-GBM antibodies
- Pulmonary haemorrhage
What type of RTA has an inability to acidify urine?
Type 1/distal RTA because distal defect -> decreased H+ secretion
Urine pH >5.5
Most common cause of type 4 RTA
Diabetic nephropathy
Blood pressure and survival in dialysis patients
Survival disadvantage with lower BP
