chronic kidney disease and renal failure Flashcards
what are the four types of function of the healthy kidney?
homeostatic function
endocrine function
excretory function
glucose metabolism
what are the homeostatic functions of a healthy kidney?
electrolyte balance
acid-base balance
volume homeostasis
what are the endocrine functions of a healthy kidney?
production of erythropoietin and 1 alpha-hydroxylase vitamin D
what are the excretory functions of a healthy kidney?
nitrogenous waste, hormones, peptides, salt and water
what is the glucose metabolism function of a healthy kidney?
gluconeogenesis and insulin clearance
in kidney failure, how is the homeostatic function of the kidney affected?
causes an increase in potassium and phosphate, a decrease in bicarbonate and pH and results in salt and water imbalance
how is the endocrine function of the kidney altered due to kidney failure?
reduced calcium
increased PTH
results in anaemia (due to lack of erythropoetin)
HOW IS EXCRETORY FUNCTION OF THE KIDNEY ALTERED DUE TO KIDENY FAILURE?
increased urea and creatinine.
lower insulin requirement
the change in homeostatic, endocrine, excretory, and glucose function of the kidney due to kidney failure, overall results in an increased risk of what type?
increased cardiovascular risk
what are the most important observatioons of a patient with kidney failure?
determine whether hypo/euvo/hypervolaemic
BP
JVP
cap refill
why might a patient with kidney failure be tachypoenic (kussmaul respiration)?
because of respiratory compensation for metabolic acidosis
what does poor skin turgor indicate?
severe dehydration
what changes to ABG occur in kidney failure?
decreased pH
decreased pCO2
increased pO2
decreased bicarb.
what is the vesicoureteral reflux?
retrograde flow of bladder urine into the ureters due to lack of component valve system in ureters
can lead to pylonephritis and scarring
what investigations are first choice for suspected kidney failure?
ultrasound (UUS KUB)
size of kidneys
check for obstruction
what are the three main effects associated with acidosis?
hyperkalaemia
anorexia
muscle catabolism
kidney failure tends to reduce secretion of salt and water, what does this lead to?
hyperytension
oedema
pulmonary oedema
is Hb high or low in chronic kidney disease?
low if chronic
can be normal in acute
how does acidosis cause hyperkalaemia?
blood contains excess H+
H+ enters cells in exchange for K+
K+ conc. in cells is lowered so it is not excreted as well resulting in hyperkalaemia
what are some of the causes of hyperkalaemia?
low distal tubule potassium
acidosis
what are some of the symptoms of hyperkalaemia?
cardiac arrythmias
neural and muscular activity
vomiting
what are the concerning complications of hyperkalaemia?
ECG changes showing arrhythmias - ventricular can be fatal
what ECG changes can be seen in hyperkalaemia?
peaked T waves
broadened and reduced P waves
QRS widening
heart block
asystole
VT/VF
what happens to: urea, creatinine, sodium, potassium and haemoglobin in kidney failure?
inc. urea
inc . creatinine
sodium can be anywhere
inc. pottasium
low Hb
what does USS KUB indicate?
normal sized kidneys with no obstruction
other than kidney failure, what other type of disease could be causing salt and water loss resulting in AKI
Salt and water loss may be seen in tubulointerstitial disorders – damage to concentrating mechanism
& hypovolemia may be the cause of AKI.
how does kidney failure result in reduced 1-25 Vit. D levels?
reduced intestinal calcium absorption so reduced serum calcium and hyperparathyroidism
how can the effects of kidney failure on metabolism be treated?
low phosphate diet
phosphate binding tablets
for patients with CKD, what is a more likely outcome, end stage renal failure or cardiovascular disease?
cardiovascular disease
how does kidney failure affect cardiovascular risk?
inflammation
oxidative stress
mineral/bone metabolism disorder
calcification of valves and vessels
what is a fistula (dialysis)
artificial connection of vein to artery, causes the vein to swell but allows easier dialysis
outline the initial steps of management for kidney failure?
1.fluid balance -give fluids/ dialysis
2. hyperkalaemia - either drive sodium into cells or out of the body
in the management of kidney failure, what can be given to help drive sodium into cells and treat hyperkalaemia?
sodium bicarbonate
insulin dextrose (caution due to high risk of hypoglycaemia)
in the managament of kidney failure, what is given to drive sodium out of the body and treat hyperkalaemia?
diuretics
dialysis
potassium binders
why should transfusions be avoided in transplantable patients with CKD?
transfusions leads to sensitisation leading to transplant failure
what cautions should be made regarding patients veins in those with CKD?
SAVE VEINS
require fistulas for dialysis
avoid venepuncture or IV in antecubital fossa or cephalic vein
use dorsum veins
what are the long term management options for kidney failure?
transplantation is aim if possible
conservative treatment - erythropoetin injections, diuretics, phosphate binders, 1-25 Vit.D supplements
dialysis- hemodialysis and peritoneal dialysis
why is urea a poor indicator of GFR?
confounded by diet, catabolic state, GI bleeding, drugs, liver function etc.
what is the kidney failure risk equation (KFRE) and what patients should it NOT be used on?
Validated risk prediction tool for kidney replacement therapy in the next two or five years for adults with STABLE chronic kidney disease (CKD) Stages 3A to 5 . NOT to be used in patient with rapidly changing eGFR.
what needs to be considered when using creatinine to assess GFR?
Affected by muscle mass, age, race, sex etc.
Need to look at the patient when interpreting the result. TREND helpful.
what needs to be considered when using 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)
when is inulin clearance used to assess GFR?
Laborious - used for research purposes only
