NEPHROLOGY Flashcards
What is ADPKD?
Inherited kidney disease
Chromosome 16 (85%) 4 (15%)
What are the features of ADPKD?
USS shows cysts, diagnostic criteria:
- two cysts, unilateral or bilateral if <30y/o
- two cysts in both kidneys if 30-59 y/o
- four cysts in both kidneys if >60y/o
HTN Recurrent UTI Abdominal pain Renal stones Haematuria CKD (can result in renal carcinoma)
What are the extra-renal manifestations of ADPKD?
- Liver cysts
- Berry aneurysms
- CVS
Mitral valve incompetence/prolapse
Aortic root dilation and dissections - Cysts in other organs e.g. pancreas
What is ARPKD?
Chromosome 6
Multiple cylindrical lesions at right angles to the cortical surface
Features in the newborn
Prenatal USS or early infancy with abdominal masss
- Polyuria and polydypsia
- HTN
End stage renal failure usually by 15
Liver involvement
What is Renal Cell Carcinoma?
Arises from PCT epithelium
Circumscribed by psuedocapsule of compressed normal renal tissue
20% Multifocal
20% Calcified
20% Cystic
How is Renal Cell Carcinoma managed?
Radical nephrectomy
Resistant to R+Ch
Biologics: a-interferon
How is Osmolality calculayed?
2 (Na+K) + GLucose + Urea
What is Acute Kidney Injury?
Rapid fall in kidney function over hours to days
Rise in serum urea and creatinine
What are the Pre-Renal causes of AKI?
Hypoperfusion:
Hypotension:
- Hypovolaemia
- Sepsis
Renal Artery stenosis:
-ACEi
What are the Intra-Renal causes of AKI?
Interstitial:
- Lymphoma
- Infection
- Tumour lysis after chemo
- Drugs
Glomerular:
- AI - SLE
- Drugs
- Infection
- Primary Glomerulonephritides
Nephrotoxins: - Drugs - Aminoglycosides - Radiocontrast - Myoglobin - Acute Tubular Necrosis Myeloma and Hypercalcaemia
Vascular:
- Vasculitis
- Malignant HTN
- Thrombus or Cholesterol Emboli from Angiography
- HUS/TTP
- Large vessel occlusion
What are the causes of post-renal AKI?
Luminal:
- Stones
- Clots
- Sloughed papilale
Mural:
- Malignancy
- BPH
- Strictures
Extrinsic compression:
- Pelvic malignancy
- Retroperitoneal fibrosis
What are the risk factors for AKI?
>75 y/o CKD Heart Failure Peripheral Vascular Disease Chronic liver disease Diabetes Drugs Sepsis Reduced Hypovolaemia Other urinary issues
What are the features of AKI?
Maintain fluid balance:
- Reduced BP
- Non-visible JVP
- Increased pulse
Hyperkalaemia
Uraemic Encephalopathy
What is KDIGO
1
SC: >2.6umol or >1,5x in 48 hours
UO: <0.5ml/kg/hr over 6 hours
2
SC: 2-2.9x baseline
UO: < 0.5ml/kg/hr over >12hours
3
SC: >3x baseline
UO: <0.3ml/kg >24 or 0 for 12 hours (Anuria)
What is Chronic Kidney Disease?
irreversible sometimes progressive loss of renal function over >3months to years
How is eGFR calculated?
MDRD =eGFR= 175 x Serum Creatinine x Age x 0.742 if F x 1.212 if black
175 Creatinine Age Gender (women get paid 0.742) Ethnicity 1.212 (iggy azalea is black) s
Affected by: pregnancy, muscle mass, eating red meat 12 hours prior
Also test with USS <9cm (shrink) and Biopsy
What are the causes of Chronic Kidney Disease?
Diabetic Nephropathy
Chronic Glomerulonephritis (e.g. IgA)
Chronic pyelonephritis and Reflux Nephropathy
HTN (Furosemide or endovascular disease)
Adult polycystic kidney disease
Alport’s
What are the complications of CKD?
Oedema
Restless legs
Acidosis
Bones
- Reduced vitamin D (OSTEOMALACIA) increased Phosphate Hypercalcaemia leading to SECONDARY HYPERPARATHYROIDISM (increased PTH) > Stage 3 - Osteitis Fibrosa Cystica -> Brown Tumour
OSTEOSCLEROSIS
OSTEOPOROSIS
Anaemia
- Reduced Erythropoetin
- Reduced iron absorption
- Reduced RBC survival especially in Haemodialysis
- Uraemia is toxic to bone: reduced erythropoesis
NORMOCHROMIC NORMOCYTIC ANAEMIA
What are the stages of CKD?
1: >90ml/min + other signs of damage
2: 60-90 + other signs
3a: 45-59
3b: 30-44
4: 15-29 severe reduction
5: <15 kidney failure
<10 ml immediate dialysis
(<15 in diabetics)
What is SIADH?
Hyponatraemia secondary to excessive water retention
Concentrated urine with Na+ >20mmmol/L and osmolality >100moskg
Plasma Na+ <125 and osmolality <260
In the absence of hypovolaemia, oedema or diuretics
What can cause SIADH?
Malignancy:
- Small cell lung cancer
- Pancreas
- Prostate
Infections:
- TB
- Pneumonia
Drugs:
- SSRIs/Tricyclics
- Carbemazapine
- Cyclophasphamides
Neurological:
- Stroke
- Subaracchnoid haemorrhage
- Subdural
- Meningitis
- Abscess
How is SIADH managed?
Correction should be SLOW to avoid precipitating CENTRAL PONTINE MYELINOSIS
- Fluid restriction
- ADH receptor antagonists: DEMECLOCYCLINE
What are the types of renal stones?
CALCIUM OXALATE
CYSTINE
URIC ACID
STRUVATE
CALCIUM PHOSPHATE
Calcium Phosphate stones
10%
In Type 1 and 3 Renal Tubular Acidosis
High urinary pH i(>5.5) ncreases supersaturation of Calcium and Phosphate
Radio-opaque like bone
Calcium Oxalate stones
85%
HYPERCALCURIA, HyperOXALURIA, HypOCITRATURIA (citrate usually complexes with Ca2+ to increase solubility)
Variable pH
Stones are radio-opaque but not as opaque as Calcium Phosphate stones
Give CHOLESTYRAMINE and PYROXIDIEN to reduce urinary OXALATE secretion
Uric Acid stones
10%
Low urinary pH
PURINE METABOLISM in diseases with extensive TISSUE BREAKDOWN and children with METABOLIC DISORDERS
Radiolucent
ALLOPURINOL and URINARY ALKALISATION e.g. with BICARBONATE
Struvite stones
20%
Alkaline urine >7.2
Crystals precipitate
Caused by UREASE PRODUCING BACTERIA (e.g. Chronic UTIs)
Slightly Radio opaque
Magnesium + Ammonium + Phosphate
Cystine stones
1%
A.R Transmembrane cystine: reduced absorption of cystine from intestine and reanl tubus
Semi-radiodense ‘ground gladd’
Normal pH, may have lots of stones
How are renal stones detected on imagine?
- USS
- Non-contrast CTKUB (kidneys, ureters, bladder)
How are renal stones managed?
- Diclofenac for analgesia
- a-adrenergic blockers to aid passage
- Stones >5mm usually pass spontaneously, if not…
Shock-wave lithotripsy <2cm
Ureteroscopy <2cm in pregnancy
Percutaneous nephrolithotopy
What are staghorn stones?
Struvite: complex, involve the renal pelvis and extend into > 2 calyces
