Chronic Kidney Disease & Renal Failure Flashcards
What is CKD?
CKD is defined as abnormalities of kidney structure or function, present for >3 months.
What GFR parameter defines CKD?
• GFR <60mL/minute/1.73m2
What are the symptoms of CKD?
Albuminuria/proteinuria, haematuria, electrolyte abnormalities detected by imaging.
What endocrine functions are performed by the kidneys?
Erythropoietin synthesis
1-alpha hydroxylase vitamin D
What homeostatic are performed by the kidneys?
Electrolyte balance
Acid-base balance
Volume homeostasis
What are the excretory functions of the kidneys?
Nitrogenous waste
Middle sized molecules
Hormones, peptides
Salt and Water
What are the functions of the kidney regarding glucose metabolism?
Gluconeogenesis
Insulin clearance
Disruptions to the homeostatic balance of the kidneys can manifest as what?
Hyperkalaemia
Reduced bicarbonate - decreases pH and manifests as metabolic acidosis
Increased phosphate
Salt want water imbalance
What are the endocrine imbalances that occur in kidney dysfunction?
Increased PTH
Anaemia - reduced EPO production
Hypocalcaemia- reduced calcitriol synthesis
Why is there parathyroid hyperplasia associated with kidney dysfunction?
There is a reduction of calcitriol synthesis, due to insufficient activity of renal 1-alpha hydroxylase, manifesting as chronic hypocalcaemia, this increases PTH secretion to potentiate bone resorption
Why does anaemia occur in kidney dysfunction?
Reduced erythropoeitin production
What are the symptoms associated with kidney failure and reduced secretion of sodium chloride?
Hypertension
Oedema
Pulmonary Oedema
Why is salt and water loss evident in tubulointestinal disorders?
Damage int he concentrating mechanism of the juxtamedullary interstitial - water reabsorption decreased
Why does metabolic acidosis occur in kidney failure?
Reduced excretion of hydrogen ions from the distal convoluted tubule into the filtrate, manifests as acid retention
Why does hyperkalaemia occur in kidney failure?
Reduced potassium excretion
What is used to treat hyperkalaemia in an acute setting?
Sodium bicarboante- neutralises the hydrogen ions, such that potassium can re-enter the cells
What can acidosis cause?
Anorexia and muscle catabolism
What are the symptoms of hyperkalaemia?
Cardiac arrhythmias
Neural muscular activity
Vomiting
What features on an ECG suggest hyperkalaemia?
Peaked T waves P-waves: Broadens, reduced amplitude QRS widening Heart block Asystole VT/VF
What type of hyperparathyroidism is linked with chronic kidney failure?
Tertiary hyperparathyroidism
Why is there an increased cardiovascular risk with chronic kidney disease?
There is an increased cardiovascular risk, since cardiac ventricular myocyte contraction is directly related to extracellular concentrations of calcium (arrythmias) + increased calcification risk.
• Predictor of end stage renal failure is CKD
• Outcome for a patient with CKD Cardiovascular disease
What are the standard cardiovascular risk?
Hypertension
Diabetes
Lipid abnormalities
What is the immediate treatment in a patient with hypovolaemia?
Give fluids
What is the immediate treatment for a patient with hypervolaemia?
Fluid restriction, consider diuretics/dialysis
What is the treatment for hyperkalaemia?
Drive into cells – sodium bicarbonate
Insulin dextrose (caution) – carries hypoglycaemic risk. Insulin is a potassium drive (short term solution)
Drive out of the body – Diuretics/dialysis
Gut absorption – Potassium chelating agents
How does insulin dextrose treat hyperkalaemia?
Insulin induces a potassium drive (short-term solution).
What is the long term management for CKD?
- Erythropoietin injections to correct anaemia
- Diuretics to correct salt-water overload
- Phosphate binders
- 1-25 Vitamin D supplements
What home therapy is available for CKD?
- Haemodialysis
- Peritoneal dialysis/assisted programmes The peritoneum behaves as a semipermeable membrane and a dialysate is delivered with specific concentrations (hyperosmolar to generate drive, fluid into the peritoneal cavity)
What is a fistula in terms of CKD?
A fistula is created by connecting an artery directly to the vein – vein swells for ease of access.
Where should taking blood be avoided in patients with renal failure?
avoid taking blood or inserting IV lines into the veins of the antecubital fossa or cephalic vein at wrist level
Which veins should be used when taking blood or IV lines for patients with renal failure?
Dorsal venous structures
Why should transfusions be avoided in patients with renal failure?
• Transfusions will sensitise anaemia (haemolytic anaemia, as foreign antigens are detected, and antibodies are formed) Autoimmune mediated rejection of transplanted kidney).
Why is urea a poor indicator of GFR?
Poor indicator
Confounded by diet, catabolic state, GI bleeding (bacterial breakdown of blood in gut), drugs, liver function
What factors affect creatinine within patients with renal failure?
Affected by muscle mass ,age, race and sex
What is the most appropriate radionucleotide studies in patients with renal failure?
EDTA
What calculation is used, to estimate GFR in patients?
Modification of Diet in Renal Disease (MDRD)
GFR (mL/min/1.73m2) = 175 x (SCr)-1.154 x (Age)-0.203 x (0.742 if female) x (1.212 if Afr American)
or
CKD Epidemiology Collaboration (CKD-EPI)
GFR = 141 x min (SCr/K,1)-α x max (SCr/K,1)-1.209 x 0.993Age x 1.018 [if female] x 1.159 [if black]
Which GFR-CKD classification is recommended by NICE and why?
NICE guidelines to use CKD-EPI (At high GFR, it is more accurate)
