Renal Cram Flashcards
Factors stimulating renin release from juxtaglomerular cells?
Sympathetic nervous system increase
Hypotension
Low renal blood flow - reduced sodium chloride concentration in distal tubule detected by macula densa
Effects of angiotensinII?
- Vasoconstriction/increase in MAP
- Constriction of renal efferent > afferent arterioles – increases GFR/increases Na resorption
- Aldosterone secretion – sodium/water retention in DCT/CD
- Posterior pit ADH release – increases DCT/CD Na/water resorption
- Thirst
Aldosterone effects?
Stimulates Na/K/ATPase pump collecting tubule
Increases sodium permeability via epithelial Na channe;
ADH stimulus and effects?
Stimulus: Hyperosmolarity and hypotension
Effects: Increases water permeability of distal collecting tubule + collecting duct via aquaporin
Site of sodium resorption?
Proximal tubules (60-65%) Na/K/ATPase pump
Site of water resorption controlled by ADH?
Collecting duct
Renal response to acidosis and alkalosis?
Alkalosis - reduction in HCO3 resorbed
Acidosis - secretion of additional H+
Why is growth poor in chronic acidosis?
Bone derived phosphate is used by kidneys as a buffer when bicarb levels are chronically low
Proximal renal tubular acidosis (type 2 RTA) features?
Urine pH <5.5
High urine bicarb & citrate
Secondary bone demineralisation due to phosphate wasting
Distal renal tubular acidosis (type 1 RTA) features?
Urine pH >5.5
Low urine osmol gap
Low ammonium excretion
How to calculate anion gap?
Na - (Cl + Bicarb)
Remember to adjust for albumin
Amino aciduria/proteinura
Glycosuria
Polyuria
Hypophosphatemia
Renal Fanconi
Renal Fanconi
Blond hair
Corneal crystals
Cystinosis
Male
Fanconi
Nephrocalcinosis
Dent’s
Nocturia/polyuria Muscle spasms Low K+/Mg Normal/high renin and aldosterone Urine calcium low
Gittelman
Autosomal recessive
Polyuria and dehydration Hypokalaemia Growth and mental retardation High renin and aldosterone Urine calcium high
Bartter
Autosomal recessive
Low serum osmalality
High urine osmolality
Euvolaemic
Low serum Na
SIADH
Nephrogenic DI treatment?
Solute reduction (low na diet) Water restriction Diuretics
Causes of post-renal AKI?
Sludge/Stones (dilated renal pelvis w no urine in bladder)
Trauma/clots
Tumours
Bladder outlet obstruction
Causes of pre-renal AKI?
True intravascular depletion - blood loss, intestinal loss, insensible loss
Effective renal hypoperfusion - hypotension (heart failure/septic shock etc)
Differences between pre-renal AKI and acute tubular necrosis?
Pre-renal AKI has high urine osmolality and low urine Na
Pre-renal AKI has bland urine, ATN has casts
Causes of renal AKI?
Insult to renal parenchyma: Renal vein thrombus Vasculitis, HSP, HUS, glomerulonephropathies Pylonephritis, interstitial nephritis ATN
Microangiopathic haemolytic anaemia
Thrombocytopenia
AKI
+/- bloody diarrhoea
Haemolytic Uraemic Syndrome
Blood tests for suspected HUS?
FBE and film - anaemia, thrombocytopenia, schistocytes
Bilirubin - high
LDH - high
Haptoglobin - low
Coags - fibrinogen normal (excludes DIC)
UEC - K+ normal due to diarrhoea loss, AKI
Cause of diarrhoea positive HUS?
Shiga Toxin
E Coli
Most common cause of AKI in developed world?
Shiga Toxin HUS
Management that best decreases chance of renal failure in early HUS?
IV fluid resus early
Recurrent episodes of Hypertension Haemolytic anaemia Thrombocytopenia AKI Low c3
Atypical HUS (complement mediated)
Strenuous exercise Muscle pain Swelling AKI Bright red urine High CK
Rhabdomyolysis
-> manage with hyper hydration
Recent illness or NSAID/antibiotic AKI Sterile pyuria White cells and WBC casts Elevated urine protein:Cr ratio
Acute interstitial nephritis
Indications for renal replacement therapy?
Electrolyte disturbance unable to be managed medically
Symptomatic uraemia - bleeding, pericarditis, encephalopathy
Severe fluid overload - pulmonary oedema, HTN, heart failure
CLCN5 mutation
Dent
Best imaging modality for: Infection Scarring Reflux Obstruction Drainage
Infection - US/MCU Scarring - DMSA Reflux - MCU, DTPA Obstruction - DTPA or IVU Drainage - IVU CT urogram
Difference between DTPA and DMSA and MAG3 scans?
DTPA best for assessing tubes - outflow
DMSA best for assessing parenchyma - scarring
MAG3 does both well
Kidney lesion in tuberous sclerosis?
Angiomyolipoma
Features of nephritic syndrome?
Proteinuria, haematuria, red/white cell casts in urine
Rising creatinine
Hypertension
Features of nephrotic syndrome?
Proteinuria +++
Peripheral oedema ++
Differential diagnosis (renal causes) of macroscopic haematuria?
UTI Stones Renal vein thrombus IgA nephropathy Alport
Heavy proteinuria
RBC & WBC on urine dip
AKI
Biopsy shows cellular crescents in glomeruli
Rapidly Progressive GlomeruloNephritis (RPGN)
Nephritis + positive strep serology/anti-DNase B?
Post-Strep GN
Nephritis + anti-ds DNA OR ANA positive?
SLE
Persistent low c3 (>4-6 weeks) with nephritis?
SLE Membranoproliferative GN (MPGN)
Nephritis + high IgA level?
IgA nephropathy
HSP
Nephritis + pulmonary haemorrhage?
Goodpastures
Goodpastures pathogenesis and biopsy findings?
Antibody mediated
Linear Ig staining of basement membrane
How to differentiate glomerular haematuria from non-glomerular?
Glomerular - casts, dysmorphic RBCs, concurrent proteinuria
Non-glomerular - normal RBCs without casts and no proteinuria
What causes hypertension in nephritic syndrome?
Salt and water retention causes suppression of renin leading to HTN
Kidney biopsy findings in PSGN?
Neutrophils in capillary loops
Double contour of glomerular basement membrane on biopsy?
MPGN
HSP associated with what increases risk of progression to CKD?
Nephrotic syndrome at outset of disease increases risk of progression to CKD by 50%
Gross haematuria with proteinuria
Concurrent URTI sx
Recurrent
Ig A nephropathy
- Elevated IgA
- Mesangial IgA deposition
Insidious onset nephritis
Joint pain
Vasculitis
Uveitis
ANCA vasculitis
Uveitis
Urine - protein, glucose, no RBC/WBC
Tubule-interstitial nephritis with uveitis syndrome
Alport genetic mutation
X-linked
COL4A5 mutation
Important features of alport?
Anterior lenticonus on eye exam
Deafness
Leiomyomatosis (smooth muscle tumours)
Basket weave GBM on biopsy
Polyuria, polydipsia Short stature Anaemia Bland urinalysis US shows normal/small kidneys with loss of corticomedullary differentiation
Juvenile nephronopthithis
Nephrotic syndrome - mesangial sclerosis
Wilms tumour
Female genitalia with 46XY chromosome
Denys-Drash
WT1 mutation
Syndromes associated with Wilms?
Beckwith-Widemann
Denys-Drash
WAGR
Frasier
Most important dietary factor in renal stone development?
High sodium diet - resulting in increased sodium and therefore calcium excretion in kidney causing calcium stones
Non-blanching skin lesions
Neuropathic pain
Heat intolerance
Proteinuria
Fabry disease
X-linked lysosomal storage disorder
How to calculate fractional sodium excretion?
Urine sodium X serum creatinine
Divided by
Urine creatinine X serum sodium
x100 (expressed as %)
Difference in protein defects in ARPKD and ADPKD?
ARPKD - fibrocystin protein defective
ADPKD - polycystin 1 & 2 proteins defective
Renal SEs of lithium?
Nephrogenic DI
Due to ADH resistance
Extra-renal manifestations of infantile nephronopthisis?
Retinitis Pigmentosa
Hepatic fibrosis
Cardiac defects (septal defects, situs inversus)
Skeletal abnormalities
Management of giggle incontinence?
Timed voiding
Oxybutinin
Renal and vaginal agenesis
Mayer-Rokitansky-Kuster-Hauser syndrome
Coloboma, Renal abnormalities, SNHL, Seizures Joint laxity
Renal-Coloboma Syndrome
PAX2 mutation
Difference in defect location in Bartter and Gitelman syndromes?
Bartter - sodium resorption at loop of hence defective
Gitelman - sodium resorption at distal tubule defective
