Chronic kidney disease Flashcards
Chronic kidney disease : Definition
Refers to decline in kidney function over 3 months
Chronic kidney disease : Causes
- Hypertension
- Diabetes
- Lupus
- HIV
- Rheumatoid arthritis
- Long term NSAID use
Chronic kidney disease : Causes : Hypertension - Pathophysiology
- Walls of the glomerulus behind to thicken to withstand the pressure
- This narrows the lumen reducing the blood flow to the kidneys resulting in ischaemic injury
- Immune cells like macrophages enter the damaged glomerulus
- This causes the mesangial cells to regress to their more immature stem cell state known as mesangioblasts
- Mesangioblasts secrete excess extracellular matrix leading to glomerulosclerosis and reduce functioning of the kidneys
Chronic kidney disease : Causes : Diabetes- Pathophysiology
- Excess glucose in the blood sticks to the proteins in the blood
- known as non enzymatic glycasion because no proteins are involved,
- This affects the efferent arterioles causing them to become more stiff and narrow known as hyaline arteriosclerosis
Chronic kidney disease : Complications
1 . Azotemia - accumulation of urea in the blood due to reduced eGFR, this causes astereixis, pericarditis, nausea + vomitting
* High risk of bleeding - excess urea inhibits platelet activity, resulting in less clot formation
2 . Hyperkalaemia - due to lack of excretion of potassium
3 . Hypocalcaemia - less activated vitamin D so less calcium is absorbed.
* Brittle bones : Low calcium levels trigger parathyroid hormone to release calcium from bones leaving them weaker
4 . Hypertension : low eGFR results in renin released which in turn will further increase blood pressure
5 . Anaemia : kidney dysfunction reduces erythropoetin release
CKD : Complications - Anaemia - causes + management
Causes :
1. Reduced secretion of Erythropoietin :
* 2nd to renal dysfunction
* Toxic effect of uraemia on bone marrow
Management :
1. Target Hb 100-120
2. Erythropoietin stimulating agent - determine iron status prior
3. Offer oral iron - if target levels nor reached within 3 months switch to IV iron infusion
CKD : Complications - Bone disease - causes + management
Causes
1. Secondary hyperparathyroidism : due to low calcium, high phosphate and low vitamin D
Clinical manifestation : Osteomalacia, osteoporosis
Management
* Reduce dietary intake of phosphate
* Phosphate binders - Sevelamer
* Vitamin D supplements
* Parathyroidectomy may be needed in some cases
CKD : Complications - Hypertension - Management
1 . First line :
* Ace inhibitors (helpful in proteinuria)
2 . Second line when eGFR <45 -
* Furosemide - useful as an antihypertensive in CKD, also reduces K+ levels
CKD : Complications - Proteinuria - referral criteria
NICE recommends using albumin: creatinine ratio has it has higher sensitivity
ACR of 3mg/mmol or more is clinically important proteinuria
Referral to nephrologist if;
- ACR > 70 mg/mmol unless known cause is diabetes and is already being treated
- Urinary ACR 30mg/mmol > with persistent protein uria after UTI is excluded
- ACR 3 - 29 with haematuria and RF such as CVS disease, declining eGFR.
CKD : Complications - Proteinuria - Management
-
Ace inhibitors
* CKD and hypertension or ACR >30
* If ACR >70 regardless of BP
2 . SGLT-2 inhibitors - Patient with CKD and proteinuria
* Acts by blocking reabsorbtion of glucose in the proximal tubule and also reduced sodium reabsorption which reduces intravascular volume and blood pressure.
CKD STAGE 1 AND 2
REQUIRES MARKERS OF KIDNEY INJURY
Haematuria - Ix
Haematuria - referra;
Hyperacute rejection (minutes to hours)
Acute graft failure
Chronic graft failure
Complications of renal graft
Rhabdimyolysis
