CKD Flashcards
What is CKD?
- Progressive deterioration of renal function over months to years
- Usually irreversible
- Deterioration can be slowed with treatment
How is CKD measured?
- Estimated GFR (eGFR)
Why is CKD irreversible?
- Renal tissue is replaced by extracellular matrix in response to damage
What are some risk factors for CKD?
- Type 2 diabetes
- Hypertension
- Renovascular disease
Why is type 2 diabetes a risk factor for CKD?
- Efferent arterioles cannot constrict and dilate when BP changes
Why is hypertension a risk factor for CKD?
- More pressure on glomerulus
- Regulatory mechanisms for controlling GFR no longer work
- Scarring and damage to fine capillaries
- 80-85% of CKD patients are hypertensive
Why is renovascular disease a risk factor for CKD?
- Narrows arteries that supply kidneys
How does type 2 diabetes cause hyperfiltration?
- Blood glucose is reabsorbed with Na+
- Less Na+ present at end of PCT
- Due to increased glucose uptake earlier in tubule
- Less Na+ is delivered to macula densa
- Interpreted as low BP
- RAAS is activated
- Increases BP
- More filtration occurs
- Causes damage to capillaries over time
How can hypertension be treated?
- Want to treat before kidneys are damaged and progress to end renal failure
- Anti-hypertensives
- Diuretics
- Fluid restriction
What is the primary aetiology of CKD?
- Polycystic kidney disease
- Acute tubular necrosis
- Recurrent pyelonephritis
- Glomerulonephritis
What is the secondary aetiology of CKD?
- Diabetes mellitus
- HTN
- Reno-vascular disease
- Auto-immune
How does CKD affect the structure of the kidney?
- Severe atrophy
- Especially of cortex
- Collecting system is affected less
- Lose functional tissue of kidney
Why is HbA1C not a good method of monitoring glucose levels in patients with CKD?
- HbA1C is glycosylated haemoglobin
- Patients with CKD often can’t make erythropoietin
- Less production of RBCs
- Patients are often anaemic
- Fasting plasma glucose better
How do you treat patients that are anaemic and have CKD?
- EPO supplements
- Iron supplements
If a patient has fluid overload and CKD, how should we treat them?
- Loop diuretics
- Inhibit NKCC co-transporters
- Eliminate large quantities of fluid rapidly
- Use a bigger dose than in a patient without CKD
Why might a patient with CKD become acidotic?
- Would be metabolic acidosis
- Kidney can’t preserve bicarbonate
- Give sodium bicarbonate to correct pH of blood
Outline calcium homeostasis
- Impaired renal function causes decreased active vit D
- Leads to decreased Ca2+ absorption from gut
- Plasma Ca2+ decreases
- Also leads to decreased PO4 excretion
- Plasma PO4 increases
- Decreased Ca2+ and increased PO4 stimulates parathyroid glands and causes hyperplasia
- Increases bone resorption
- Lack of active vit D impairs bone mineralisation
What is uraemia?
- Nitrogenous compounds increase in blood
What are some of the symptoms of uraemia?
- Vomiting, nausea, poor appetite
- Dry skin, brittle nails
- Heart failure
- Muscle weakness, bone pain,
- Swelling
- SOB
What happens to the functions of the kidneys due to CKD?
- Can’t control acid/base, K+, PO4-, or fluid levels
- Can’t excrete K+, PO4-, creatinine, or urea
- Deranged RAAS
- Decreased EPO and vit D
- Can’t regulate concentration of fat soluble vitamins
- less glucose reabsorbed
When do we need to put a patient on renal replacement therapy?
- When renal function declines to a level no ,longer adequate to support health
- eGFR 8-10
What are the 3 types of renal replacement therapy?
- Haemodialysis
- Peritoneal dialysis
- Renal transplant
What are the pros of haemodialysis?
- Less responsibility
- Days off
- Proven effective long-term
What are the cons of haemodialysis?
- Time consuming
- Patient is tied to dialysis times
- Access/line problems
- Fluid/food restrictions
How does haemodialysis work?
- Blood is taken from patient
- Anti-coagulant is added
- Counter-current flow of dialyzer removes waste products
- Haemofiltration uses a membrane similar to glomerulus
- Blood put back into patient
How does peritoneal dialysis work?
- Peritoneum is used as a membrane to dialyse blood
What are the pros of peritoneal dialysis?
- Continuously done at home, allows for independence
- Less fluid/food restrictions
- Easy to travel
- Renal function may be better preserved initially
What are the cons of peritoneal dialysis?
- Frequent daily exchanges/overnight
- Responsibility
- Peritonitis
- Less long-term survival data
What is the gold standard treatment for CKD?
- Renal transplant
- Both parties can survive with one kidney
