Week 2 Renal Chronic Kidney Disease Flashcards
Definition of chronic kidey disease
GFR of less than 60 ml/min for >90 days /3 months
What are the 5 stages of chronic kidney disease as defined by eGFR.
Think clock into four quarters with one quarter split into 2
Stragtagies to prevent CKD
- Control blood pressure (RAS inhibition)
- Reduce proteinuria (RAS inhibition)
- If diabetes, optimise glycaemic control
- SGLT2 inhibitors (not just for diabetics, they have a protective effect on the kidneys and heart)
Is proteinuria a marker or cause of progressive renal disease?
Both
Indicator of kidney damage: Protein in the urine reflects damage to the glomerular filtration barrier.
Cause: Filtered proteins can be reabsorbed by proximal tubular cells, triggering inflammation, oxidative stress, and fibrosis. The presence of protein can stimulate cytokine production and attract immune cells, worsening interstitial damage.
Potential toxins to avoid in CKD
NSAIDs / Contrast / Gentamicin /
Phosphate enemas
What are blood pressure treatment goals for CKD?
BP treatment goals
“normal” - 130/80
DM / Proteinuria 125/75
In CKD if the glomerulus becomes more leaky why does GFR decrease?
This is because although in parts there are larger holes, the overall glomerulus is damaged, in some parts the basement membrane is fibrosed resulting in no flow at all, in other parts the efferent arterioles are weakened and unable to apply pressure.
What happens to potassium in CKD?
What advice should you give?
Hyperkalaemia common as GFR declines < 25
May occur at GFR>25 if Diabetes and type 4 RTA, ACE inhibitors, High K Diet present
Advice would be a low K diet, K monitering and potential use of potassium binders
In CKD why are you more likely to develop acidosis?
Because the kidneys can’t excrete H+
What advice should you be aware of with CKD and acidosis?
Aim to keep Serum HCO3 >22
Replace with bicarbonate
Note that animal proteins tend to contribute to higher H+ levels
What is the treatment for anaemia in CKD?
Erythropoietin
All pts with Hb < 105 and adequate iron stores should be on Epo
If poor response to EPO
Check iron stores / CRP / B12 +folate / PTH/Aluminium/ malnutrition / malignancy
Why does CKD lead to anaemia?
Erythropoietin (EPO) is a glycoprotein hormone produced by the peritubular cells of the renal cortex. This hormone stimulates red blood cell production in response to low partial pressure of oxygen (pO2). If the kindney is damaged the body makes less EPO
What causes renal osteodystrophy?
During renal failure you are unable to excrete phosphate and unable to make calcitriol resulting in hypocalcaemia.
The combination of high phosphate and low calcium trigger excessive PTH activity resulting in worsening of bones.
Difference between high turnover bone disease and low turnover bone disease
High turnover bone disease:
Secondary hyperparathyroidism - PTH rapidly breaking down bone
Low turnover bone disease:
Osteomalacia - lack of calcitriol causes bone to be unable to harden properly
In CKD do you see high turnover bone disease and low turnover bone disease
Both
Treatment for renal osteodystrophy
- Phosphate restrict (0.8-1.0g/kg/day)
* diet (0.8-1.0g/kg/day)
* binders- calcium or non-Ca binders - Vitamin D therapy (alfacalcidol)
* increases Ca / decreases PO4 - Monitor PTH 6/12ly
* keep 2-3 x normal - Parathyroidectomy may be required
Consequences of hyperphosphataemia
Vessel calcification:
High phosphate in the blood actually begins to trick vessel cells into thinking they are osteoblasts, this phosphate then combines with calcium and begins to lay down bone in the blood vessels, this results in non-compliant vessels leading to
Systolic hypertension – L Vent Hypertrophy
Diastolic hypotension - Myocardial ischaemia
Another problem is Calciphylaxis
With regards to vessel calcification fill in these two types
Why is cardiovascular disease such an issue in CKD?
CKD leads to so many issues which could cause CKD
- Raised BP
- Hyperphosphataemia
- Anaemia
Why is malnutrician an issue in CKD?
Malnutrition common in CKD
* Decreased protein intake – dietary restrictions
* Decreased appetite
* Low albumin - ?related to inflammation/infxn
What are the seven big issues that occure in CKD?
a) Excretory
* Salt and Hypertension
* Potassium
* Acidosis
b) Endocrine
* Anaemia
* Renal Osteodystropy
* Cardiovascular risk
* Malnutrition
Who should you refer to a renal clinic?
Any patient with rapid increase in creatinine/ hypertension
Stage 3 CKD with hypertension/ proteinuria /haematuria/ rising creatinine
Any stage 4/5 CKD who is suitable for treatment
How does peritoneal dialysis work?
A catheter is surgically placed into your abdomen (peritoneal cavity).
A special dialysis fluid (called dialysate) is infused into your abdomen through the catheter.
The dialysate sits in your belly for a few hours (called the dwell time).
During this time, wastes, toxins, and extra fluid pass from your blood (via the peritoneal membrane) into the dialysate.
After the dwell time, the used fluid is drained out, and fresh dialysate is put in — this process is called an exchange.
What is the cycle of care after a kidney transplant?
