chronic kidney disease and renal failure Flashcards
what are the homeostatic function of the kidneys
electrolyte balance
acid base balance
volume homeostasis
what are the endocrine functions of kidneys
production of erythropoietin
production of 1alpha hydroxylase for vitD
what are the excretory functions of the kidneys
nitrogenous base hormones peptides 'middle sized molecules' salt and water
what are the kidneys roles in glucose metabolism
gluconeogenesis
insulin clearance
what happens when homeostatic function in kidneys fail
increased potassium decreased bicarbonate decrease in ph increased phosphate salt and water imbalance
what happens when endocrine function in kidneys fail
hypocalcaemia
hyperparathyroidism to compensate
anaemia from reduced erythropoeitin
what happens when excretory function in kidneys fail
increased urea
increased creatinine
decrease in insulin requirement
what effect can kidney failure have on cardiovascular risk
increase it
clinical signs of kidney failure
symptoms of extreme lethargy, weakness and anorexia
severe hypotension - from vol depletion
elevated plasma urea and creatinine
usually small kidneys
what is used to make diagnosis of renal failure
elevated plasma urea and creatinine
complications of renal failure
hyperkalaemia
hyponatraemia
metabolic acidosis
anaemia
kidney failure tends to reduce secretion of salt and water leading to
hypertension
oedema
pulmonary oedema
what are some other causes of salt and water loss
tubulointerstitial disorders - damage to concentrating mechanism
hypovolemia can also cause aki
what causes acidosis
reduce excretion of h+ ions
retention of acid bases by cells
forces k+ out cells
what does acidosis lead to
anorexia
muscle catabolism
leads to weakness
what are some cause of hyperkalaemia in renal failure
decreased distal tubule potassium secretion
acidosis
what are the symptoms of hyperkalaemia
usually depends on chronicity
cardiac arrythmias
neural and muscular activity
vomiting
what are some ecg changes that can be seen in a patient with hyperkalaemia
peaked t waves p wave broadens- reduced amplitude then diasappear qrs widening heart block asystole vt/vf
what are the standard cardiovascular risk with kidney failure
hypertension
diabetes
lipid abnormalities
how to initially manage hypovolemia
give fluids
how to initially manage hypervolemia
trial of diuretics / dialysis
what are some ways to manage hyperkalaemia in kidney failure
-drive k+ into cells - sodium bicarbonate and insulin dextrose (caution)
- drive k+ out of body - diuretics/ dialysis
gut absorption - potassium binders
what is the conservative long term treatment for kidney failure
- erythropoietin injections to correct anaemia
- diuretics to correct salt overload
- phosphate binders
- 1.25 vit d supplements
- symptom management
what is the home therapy to treat kidney failure
haemodialysis
peritoneal dialysis/assisted programmes
in centre therapy for long term management for kidney failure
haemodialysis
4hrs for 3 times a week
aim for transplantation for all healthy patients
methods for assessing gfr
- urea - poor indicator and confounded by diet,catabolic state, gi bleeding,drugs, liver function
- creatinine - affected by mass,age, race, sex
- creatinine clearance - difficult for elderly patients to collect accurate sample and overestimates gfr
- inulin clearance - used for research purposes
- radionuclide studies for edta clearance, reliable but expensive
how do you work out an estimated gfr
serum creatinine
