Systems Pathology: Kidney failure Flashcards
Kidney functions
Which part of kidney secretes renin
Juxtaglomerular apparatus
Two main forms of clinical renal syndromes
Acute kidney injury
Chronic Kidney Disease
Define acute kidney injury
AKI describes “abrubt deterioration of renal function”
Features of AKI
- Oliguria: Abnormally small amounts of urien production
- Electrolyte imbalance: Hyperkalaemia and metabolic acidosis
- Rapidly Rising blood urea and creatine
Diagnostic criteria for AKI
- Serum creatinine rise by 26mmol/l from baseline within 48hr OR
- Serum creatinine rises 1.5. fold formbaseline value within 1 week OR
- Urine output is <0.5 ml/kg/hour for >6 hours
What happens in acute tubular necrosis
- Tubular epithelial cells have high oxygen demands so central perfusion failure means less oxygen getting through
- Tubular epithelial cells are hypoxic and die
- Function of tubular epithelial cells lost so NO ion, salt and water pumping takes palce
- Kidneys swell
Different causes of glomerular disease
- Glomerulonephritis; acute inflammation of the kdiney
- immune complex mediated disease of glomeruli e.g. SLE
- Post-infective
- Some linked to vasculitis
Vascular causes of AKI
- Vasculitis - immune-mediated inflammation and destrucion of small vessels
- DIC (disseminated intravascular coagulation)
- Malignant hypertension
Causes of post-renal AKI
- Acute obstruction of lower urinary tract e.g. enlarged prostate in males, ureters in both males and females
- Blockage of ureter by kidnyes stones
- Tumour or inflammation in the walls
- Extrinsic masses e.g.g tumour of sorrounding areas
Defien Chronic renal failure
Slowly, progressive and irreversible loss of renal fucntion due to irreversible destruction of large numbers of nephrons. Thus, gradual deterioration over many years due to large reserve capacity of nephrons. Symptoms appear when compensation fails
Symptoms of CRF
- Polyuria: increased urine output
- Malaise, lethargy
- Increasing ureamia, confusion and eventual coma
- Hypertension from Na+ and water retention
eGFR at point of dialysis
<15
CDK initiating factors
CKD perpetuating factors
Causes of CKD
Diabetic nephropathy
Diabetic nephropathy (DN), also known as diabetic kidney disease, is the chronic loss of kidney function occurring in those with diabetes mellitus. Protein loss in the urine due to damage to the glomeruli may become massive, and cause a low serum albumin with resulting generalized body swelling (edema) and result in the nephrotic syndrome
Nephrotic VS nephritic syndrome
