Renal Flashcards
What blood result is most suggestive of the diagnosis of rhabdomyolysis?
Raised CK
What characterises rhabdomyolysis?
Muscle damage and lysis of muscle cells
Cellular content degradation –> release of K, myoglobin, CK, phosphate
Why does rhabdomyolysis cause renal impairment
Excessive myoglobin release - filtered by kidney –> renal tubular damage + cast formation.
Prostaglandins etc –> renal arteriole constriction –> decreased perfusion.
Causes of rhabdomyolysis
Trauma Compartment syndrome Crush injury Ischaemia Severe electrolyte disturbance Bacterial / viral infection Inherited metabolic disorders Drugs
Criteria of nephrotic syndrome
Albumin < 35g/L
Urine protein > 3 - 3.5 g/24 hrs
Marked pitting oedema
Causes of nephrotic syndrome
Glomerulonephritis - e.g. Minimal change disease, membranous glomerulonephritis Focal segmental glomerulosclerosis Diabetic nephropathy Amyloid Connective tissue disorder - SLE
Main function of kidneys
Excretion of nitrogenous waste - from protein catabolism
= urea
What is renal tubular acidosis?
Failure of the kidney to excrete acids into the urine –> acidaemia
What is type 1 renal tubular acidosis
Distal RTA
Failure of acid secretion
Define nephrotic syndrome
> 3G Proteinuria
Low albumin
Oedema
Causes of nephrotic syndrome
minimal change glomerulonephritis Membranous nephropathy Mesangiocapillary glomerulonephritis Focal segmental glomerulonephritis Thin basement membrane nephropathy
Define nephritic syndrome
Haematuria
(Proteinuria <3g)
Hypertension
Uraemia
Causes of nephritic syndrome
Post-streptococcal glomerulonephritis
Rapidly progressive glomerulonephritis
IgA nephropathy
SLE
Pre-renal causes of AKI
Hypoperfusion (haemorrhagic shock, sepsis, severe dehydration, burns, CHF) RAS Renal vein thrombosis Drugs (NASIDS / ACEi) Pancreatitis,Cirrhosis --> ascites
Renal causes of AKI
ATN
Acute glomerulonephritis (immune)
Acute interstitial nephritis (drugs, bacteria)
Septic renal failure
Endogenous renal toxins (Hb, urate, myoglobin)
Hepatorenal syndrome
Post-renal causes of AKI
Bladder outlet obstruction (stones, tumour, clot, prostate)
Bilateral ureteric obstruction (retroperitoneal fibrosis,
What is IgA nephropathy
Autoimmune
Increased IgA forms immune complexes which deposit in mesangial cells
What is goodpastures syndrome
Anti-glomerular basement membrane disease
Autoantibodies to type 4 collagen in kidney and lung
–> macroscopic haematuria, haemoptysis
What is analgesic nephropathy
Prolonged heavy ingestion of compound analgesics (esp containing caffeine)
- -> interstitial nephritis + papillary necrosis
- -> slow progressive CRF
What is glomerulonephritis
Immunologically mediated inflammation of renal glomeruli
- -> haematuria
- -> subcutaneous oedema
- -> polyuria or oliguria
- -> proteinuria
- -> hx of recent infection
Inheritance of polycystic kidney disease
Autosomal dominant (usually) Autosomal recessive (less common)
Anatomical features of PKD
Multiple renal cysts
Gradually expanding
Replace normal kidney structure
What predisposes to UTI
Female Renal calculi Catheter Post-GA Double ureter
Presentation of PKD
30-40yo Pain in flanks due to cyst expansion, stones, blood clots, infection Haematuria Hypertension SAH from burst berry aneurysm
Causes of RAS
Older pts - atherosclerosis
Younger pts - fibromuscular dysplasia
Causes hypertension
Types of renal calculi
65% calcium oxalate 15% calcium phosphate 10% magnesium ammonium phosphate 5% uric acid 1% cystine
Risk factors for renal calculi
Dehydration Change in urine PH UTI Hypercalciuria Hypercalcaemia Oxalates Hyperuricaemia Cyst injuries Horseshoe kidney
Presentation of renal calculi
Loin to groin pain Dysuria Frequency Strangury Penis tip pain Urine retention Haematuria
What is Alports syndrome
Inherited mutation of gene coding collagen IV
–> haematuric nephritis + sensorineural deafness
What is Medullary sponge kidney
Dilation of terminal collecting ducts in medulla
Causes cysts and calcium phosphate stones
Tumour markers of testicular cancer
Alpha-fetoprotein
Beta-HCG
Antibodies in Wegeners granulomatosis
cANCA
Antibodies in goodpastures disease
Anti-glomerular basement membrane antibodies
Treatment for goodpastures disease
Steroids
Avoid smoking
Main cause of nephrotic syndrome in children?
Minimal change glomerulo-nephritis
Treatment of minimal change disease
Steroids Fluid restriction Low-salt diet Penicillin prophylaxis ACE inhibitors Statins for hyperlipidaemia
Most common cause of nephrotic syndrome in adults
Membranous glomerulonephritis
What happens in Membranous glomerulonephritis
Immune complexes form when circulating antibodies bind to basement membrane antigens, or antigens deposited in the glomerulus by the circulation.
–> immunological response
Damage glomerular basement membrane –> permeability
Causes of Membranous glomerulonephritis
90% idiopathic SLE Hepatitis B Systemic infection Drugs
Treatment of Goodpastures syndrome
Plasmapheresis
Corticosteroids
Immunosuppression
What happens in IgA nephropathy
IgA antibodies deposited in the mesangium and trigger an immune response.
Presentation of an IgA nephropathy
Urine dip - microscopic haematuria + proteinuria
Or
Frank haematuria (usually 2 days after URTI)
Diagnosis of IgA nephropathy
Renal biopsy - mesangium proliferation + expansion of extracellular matrix
Immunofluorescence shows IgA deposition
Raised serum IgA in 50 %
What is post-streptococcal glomerulonephritis
Glomerulonephritis seen 1-2 weeks post beta-haemolytic streptococcus infection
E.g. Tonsillitis / cellulitis
Features suggesting post-streptococcal glomerulonephritis
Recent Tonsillitis / skin infection Dark urine (tea / cola) Oedema Hypertension Haematuria Oliguria
Investigations for post-streptococcal glomerulonephritis
Raised Streptolysin-o
Reduced complement
Urine protein and haematuria
Management of post-streptococcal glomerulonephritis
Fluid restriction
Anti hypertensives
Low salt diet
Prognosis is usually good
Symptoms of renal colic
Severe loin pain
Radiates to groin
Patient writhes around in agony
+/- vomiting, pallor, sweating, pyrexia, haematuria
Investigation of renal colic
Urine dipstick FBC U+E KUB xray (IV urogram, CT urogram, renal tract USS)
What % of renal calculi are radio-opaque
90%
Management of renal calculi
Initial tx = supportive + analgesics - diclofenac
If stone will not pass spontaneous seek surgical opinion - extracorporeal shock wave lithotripsy, cystoscopy, uretoscopy, percutaneous nephrolithotomy
Investigation of deteriorating function in a transplanted kidney
Renal biopsy
Causes of deteriorating function in a transplanted kidney
Organ rejection
Vessel thrombosis
Infection
Recurrence of existing disease
Presentation of UTI in young children
Poor feeding
Vomiting
Lethargy
Abdominal pain
Important causes of UTI in children
Vescicouretric reflux Urinary tract obstruction Duplex ureters Constipation Sexual abuse
Features of renal TB
Sterile pyuria (leucocytes + negative culture) Lethargy Dysuria Urinary frequency Weight loss Night sweats
Features of adult polycystic kidney disease
Multiple, large cysts in the kidneys
Also in liver, pancreas and spleen.
–> renal failure and hypertension
Berry aneurysms in circle of willis –> rupture –> SAH
Management of low calcium in chronic renal failure
Prescribe alfacalcidol (vitamin D supplement)
What causes encephalopathy in renal failure?
Serum urea crosses the blood brain barrier
Features of uraemic encephalopathy
Fluctuating confusion,
cognitive impairment,
myoclonic jerk,
seizures
Treatment of uraemic encephalopathy
Dialysis
Haemofiltration in an emergency
What is Henoch-schonlein purpura
IgA mediated Autoimmune vasculitis of childhood.
Often preceded by a viral respiratory illness
Commonest renal cancer
Renal cell adenocarcinoma
Presentation of renal cell carcinoma
Haematuria
Flank pain
Palpable mass
New left sided varicocele may occur in M
Hypertension.
Polycythaemia
Hypercalcaemia
What congenital conditions may be associated with renal cell carcinoma
Von Hippel-Lindau
Tuberous sclerosis
What is Waterhouse-friedrichsen syndrome
Bilateral haemorrhage into the adrenal glands caused by meningococcal sepicaemia
What is renal osteodystrophy
Skeletal disorder seen in patients with renal failure. combination of: - secondary hyperparathyroidism - osteomalacia - vitamin D deficiency
What is secondary hyperparathyroidism
Chronic renal failure - hyperphosphataemia + reduced vit D –> chronic hypocalcaemia
Parathyroid produces more PTH in response
Promotes bone resorption –> renal osteodystrophy
Symptoms of Renal osteodystrophy
Chronic renal failure
Bone pain
Pathological fractures
(Osteomalacia)
In what 2 ways can NSAIDS cause renal problems
Haemodynamic acute renal failure
Acute interstitial nephritis with Nephrotic syndrome
Best investigation for suspected renal injury after trauma
CT
