Overview of Renal Diseases Flashcards
What are the 7 functions of the kidney?
→ Excrete waste substances → Regulates minerals in extracellular fluid → Regulates water balance → RBC production → Blood pressure control → Vitamin D activation → acid base balance
How much blood passes through the glomeruli per day?
→ 2000
How much blood is filtered per day?
→ 200 L
What tests are used to measure kidney function?
→ Blood tests → Creatinine → formulae → Urine output → Elimination of radioisotopes
What is creatinine and where is it produced?
→ biomarker for filtration of the glomerulus
→ skeletal muslce
What is asymptomatic proteinuria?
→ glomerular filter has become leaky
What is nephritic syndrome?
→ Inflammatory condition in the glomerulus
→ RBC in urine
→ hypertensive
→ GFR falls
What is haematuria?
→ blood in urine due to bleeding anywhere along the urinary tract
What is chronic kidney disease?
→ Reduction in GFR that gets worse over time
What does diabetes mellitus do to the kidney?
→ Chronic damage to kidney through high BP
What are pre renal causes of kidney disease?
→ hypovolaemia
→ Perfusion decreases
→ Drugs
How can hypovolaemia be caused?
→ Haemorrhage
→ Diarrhoea
Why does perfusion decrease?
→ Septic shock
→ Cardiac failure
How can drugs cause kidney disease?
→ Angiotensin converting inhibitors
→ NSAIDs
NSAIDs disrupt the compensatory vasodilation response of renal prostaglandins to vasoconstrictor hormones released by the body
How are glomerular diseases diagnosed?
→ Urine analysis
→ measures blood and protein
How is proteinuria quantified?
→ Urine albumin : creatinine ratio
→ Urine protein : creatinine ratio
What does glomerular bleeding lead to?
→ Red cell casts in the urine
→ Red cells get stuck together and form the shape of the tubule
How do dysmorphic erythrocytes form?
→ Red blood cells squeeze along the glomerular filter and become deformed
What do you need to distinguish between in glomerular disease?
→ primary and secondary
What is a post renal disease?
→ Acute kidney injury
What happens in acute kidney injury?
→ Fluid retention - lymphoedema leads to pulmonary oedema
→ Hyperkalaemia - high K+ leads to cardiac arrhythmias
What are the consequences of acute kidney injury?
→ Impact on outcome - hospital mortality → Resources - length of stay in hospital - referrals, tests and treatments → Patient morbidity - Acute complications - dysfunction of other organs - risk of CKD
What are the long term sequelae of acute kidney disease?
→ CKD
→ ESRF (end stage renal failure)
→ death
How is AKI measured?
changes in creatinine
If there is a problem with blood going into the kidney what is this called?
→ pre renal
if there is a problem with the kidney what is this called?
→ renal
If there is a problem with urine getting out what is this called?
→ post renal
What are intrinsic renal causes?
→ Glomerular
- glomerulonephritis
- systemic disease
→ Tubular
- acute tubular necrosis
→ Vascular and interstitial
→Interstitial
Interstitial nephritis
What are the 3 kidney compartments?
→ vascular
→ tubulointerstitial
→ glomerular
What are 3 tubulointerstitial diseases?
→ acute tubular injury
→ acute tubulointerstitial nephritis
→ chronic tubulointerstitial nephritis
What does it mean if the bleeding is in the urinary tract?
→ a symptom of cancer
What are the two ways that the glomerulus can fail?
→ Filter things it shouldn’t
→Not filter things it needs to filter (reduced GFR)
What is nephrotic syndrome?
→ Heavy proteinuria
→ hypoalbuminaemia
→ Oedema (result of hypoalbuminaemia)
→ frothy urine
What are signs of nephritic syndrome?
→ Both filter failures
→ Abrupt onset
→ reduced GFR
→blood and protein in urine
What are asymptomatic urine abnormalities and what is important in it?
→ blood or protein in urine
→ IgA nephropathy is important
What is rapidly progressive glomerular nephritis?
→ both modes of filter failure
→ Weeks or months
What is a cause of nephritic syndrome?
→ Post-streptococcal GN
What are three causes of rapidly progressive GN?
→ Goodpasture disease
→ ANCA (small vessel anti neutrophil cytoplasm antibody)
What is the first stage in AKI management?
→ Correct pre-renal factors
→ Relieve obstruction
What is the second stage in AKI management?
→ Maintain fluid and electrolyte balance
→ Nutrition
→ Gastric protection
What are the effects that indicate dialysis may be needed?
→ Oedema (pulmonary)
→ Hyperkalaemia
By what amount is your risk of cardiovascular mortality increased by when on dialysis?
→ 300 -400 x
What is CKD a marker of?
→ cardiovascular risk
How is CKD treated?
→ Treating endocrine issues
→ Ca2+, PO4, Vitamin D, PO4 binders, alfacalcidol
→ IV Fe and erythropoeitin
What are the three options for end stage renal failure?
→ Dialysis
→ Transplantation
→ Conservative management
What are the two forms of dialysis?
→ Haemodialysis
→ Peritoneal fluid
What are 2 types of donors?
→ brain death
→ cardiac death
What should be considered when deciding what time to start RRT?
Avoids: metabolic abnormalities
and problems of volume overload
Exposes patient to potential of: Venous thrombosis →Bacteraemia
→Haemorrhage from anticoagulants
What is obstructive uropathy?
→Prostatic obstruction causes 25% of AKI
→Single remaining kidneys at high risk
→Can still produce significant amounts of urine
→Delay in correction (catheter or nephrostomy) compromises renal function permanently
Indications for acute dialysis…
→Hyperkalaemia refractory to medical therapy K+ > 6.5 with ECG changes →Severe Acidosis pH < 7.25, HCO3 <15 →Fluid overload despite high-dose furosemide appropriate →Symptomatic uraemia: urea > 35 Pericarditis, encephalopathy
Describe peritoneal dialysis
→Peritoneum used as the membrane
Solute and water exchange between peritoneal capillary blood and dialysate fluid
→Membrane= vascular wall, interstitium, mesothelium and adjacent fluid films
→Small molecules transfer by diffusion
Fluid movement determined by osmosis
→Dialysate dextrose concentration
Solvent drag for middle sized molecule
Describe haemodialysis
Blood passes down one side of a highly permeable membrane
→Water and solutes pass across the
membrane
→Solutes up to 20,000 daltons
Drugs & electrolytes
→Infuse replacement solution with physiologic concentrations of electrolytes
