Chronic Kidney Disease and Renal Failure Flashcards
What is the homeostatic function of kidneys in health?
- Electrolyte balance
- Acid-base balance
- Volume homeostasis
What is the excretory function of kidneys in health?
- Nitrogenous waste
- Hormones
- Peptides
- “middle sized molecules”
- Salt and water
What is the endocrine function of kidneys in health?
- Erythropoietin
2. 1-alpha hydroxylase vitamin D
What is the glucose metabolism function of kidneys in health?
- Gluconeogenesis
2. Insulin clearance
What happens to the homeostatic function in kidney failure?
- Increase potassium
- Decrease bicarbonate
- Decrease pH
- Increase phosphate
- Salt and water imbalance
What happens to the excretory function in kidney failure?
- Increase urea
- Increase creatinine
- Decrease insulin requirement
What happens to the endocrine function in kidney failure?
- Decrease calcium
- Anaemia
- Increase parathyroid hormone
What happens as the kidney fails?
Increase cardiovascular risk
Since kidney failure tends to reduce secretion of salt and water what does this lead to?
- Hypertension
- Oedema
- Pulmonary oedema
What are the causes of hyperkalaemia?
- Decrease distal tubule potassium secretion
2. Acidosis
What are the symptoms of hyperkalaemia?
- Cardiac arrhythmias
- Neural and muscular activity
- Vomiting
What are the ECG changes in hyperkalaemia?
- Peaked T waves
- P wave
- broadens
- reduced amplitude
- disappears - QRS widening
- Heart block
- Asystole
- VT/VF
What does reduced erythropoietin lead to?
Anaemia
What does reduced 1-25 vit D levels lead to?
- Reduced intestinal calcium absorption
- Hypocalcaemia
- Hyperparathyroidism
What does chronic renal failure lead to?
- Phosphate retention
- Low levels of 1-25 Vit D
- Lead to hypocalcaemia + hyperparathyroidism
What can CKD predict?
- End stage renal failure
- But more likely to die from cardiovascular
What is the standard cardiovascular risk for kidney failure?
- Hypertension
- Diabetes
- Lipid abnormalities
What are the additional cardiovascular risks for kidney failure?
- Inflammation
- Oxidative stress
- Mineral/bone metabolism disorder
What is the initial management for kidney failure and fluid balance?
- Hypovolemic: give fluids
2. Hyervolaemic: trial of diuretics/dialysis
What is the initial management for kidney failure and hyperkalamia?
- Drive into cells: sodium bicarbonate and insulin dextrose (caution)
- Drive out of body: diuretic/dialysis
- Gut absorption: potassium binders
What is long term conservative treatment for kidney failure?
- erythropoietin injections to correct anaemia
- diuretics to correct salt water overload
- phosphate binders
- 1.25 vit d supplements
- symptom management
What is long term home therapy for kidney failure?
- Haemodialysis
- Peritoneal dialysis/assisted programmes
What is long term in centre therapy for kidney failure?
- Haemodialysis, 4 hours 3 x a week
- Transplantation ?
When should you avoid transfusions?
- In transplantable patients with kidney disease
2. Transfusions lead to sensitisation which leads to transplant failure
How do you use Urea to assess GFR?
- Poor indicator
* Confounded by diet, catabolic state, GI bleeding (bacterial breakdown of blood in gut), drugs, liver function etc.
How do you use creatinine to assess GFR?
- Affected by muscle mass, age, race, sex etc.
* Need to look at the patient when interpreting the result. TREND helpful.
How do you use radionucelide studies to assess GFR?
- EDTA clearance etc
* Reliable but expensive
How do you use creatinine clearance to assess GFR?
- Difficult for elderly patients to collect an accurate sample
- Overestimates GFR at low GFR (as a small amount of creatinine is also secreted into urine)
How do you use insulin clearance to assess GFR?
•Laborious - used for research purposes only
What can salt and water loss may also be due to?
- may be seen in tubulointerstitial disorders – damage to concentrating mechanism
- and hypovolemia may be the cause of AKI
What does hyponatremia not always equal?
Reduced total body sodium
