Lecture 3 - Renal Flashcards
What is a consequence of renal failure when hypoalbuminaemia results?
Oedema
What haematological abnormality does chronic renal failure cause?
Moderately severe, normocytic, normochromic, non-regenerative anaemia = EPO deficiency AND Urinary loss of AT - consequence of protein-losing nephropathy = hyper-coagulable (prothrombotic) state
How can urea and creatinine be used to differentiate between AKI/ARF and CKD/CRF?
Abrupt increase = AKI/ARF Progressive and slow increase = CKD/CRF
What is hyperphosphatemia a feature of all forms of azotemia?
Feature of all forms of azotemia (pre-renal, renal and post renal) - 85-90% is reabsorbed as PO4 in proximal tubule via Na-PO4 co-transporter
Where does PTH act to promote calcium re-absorption?
Ascending limb of the loop of Henle, distal tubule and the collecting tubule
Where does Vitamin D act to promote Ca2+ reabsorption?
In the distal nephron
What are the steps involved in renal secondary hyperparathyroidism?
- Renal disease (causes a loss of nephrons) meaning reduced GFR and less PO4 filitered out meaning mild hyperphosphatemia develops
- Damaged tubular cells or inhibition of a-hydroxylase by increased PO4 means less conversion of Vitamin D
- Less Vitamin D means decreased intestinal absorption and bone reabsorption
- Reduced vitamin D reduces Vitamin D inhibition of PTH synthesis
- Decreased Ca2+ causes increased PTH production and increased a-hydroxylase activity
- Increased PTH can compensate up to point, after that increased phosphate occurs
Name the condition below and state how kidney failure can cause it:
Fibrous osteodystrophy
What is increase amylase and lipase seen in cases of renal failure?
These are excreted by the kidney. Decreased GFR induce serum accumulation of amylase and lipase
Why is increase potassium seen in renal failure?
Hyperkalemia = feature of advanced post-renal azotemic and oliguric or anuric acute renal failure.
K+ movement from cell to lumen occurs through K+ channels opened by aldosterone. Enhanced when urinary flow rate through the tubule is high. High flow rate means K+ is washed away quickly and thus the concentration gradient is maintained.
Movement is reduced when urinary flow rate is lower as K+ stays in the tubule and thus concentration gradient is diminished
Is metabolic acidosis typically worse in CKD or acute renal failure?
Metabolic acidosis is typically much worse in cases of acute renal failure as the kidneys have had insufficient time to adapt
What does the finding of isothenuria suggest?
suggestive of renal failure means that the kidneys are unable to concentrate urine
What does the finding of proteinuria suggest?
Varies in severity but more likely to occur in chronic kidney disease than in acute kindey insufficiency
What finding would be indicative of glomerular damage?
Findings that are suggestive of glomerular damage:
- Proteinuria (large size protein)
- Hypoalmbuminaemia (severe proteinuria)
- Hypercholesterolaemia (urinary loss of lipase - NEPHROTIC SYNDROME)
What is renal tubular acidosis and what are the two main types that can occurs:
Proximal RTA (Type 2) = decreased HCO3- reabsorption in the proximal tubule
Distal RTA (Type 1) = defective acid excretion (impaired H+ secretion) in the collecting ducts
