Chronic Kidney Disease and Renal Failure Flashcards
What are the different functions of the kidney?
- homeostatic function
- excretory function
- endocrine function
- glucose metabolism
What is the homeostatic function of the kidney?
- electrolyte imbalance
- acid-base imbalance
- volume homeostasis
What is the endocrine function of the kidney?
- erythropoietin
- 1 alpha-hydroxylase vitamin D
What is the excretory function of the kidney?
- nitrogenous waste
- hormones
- peptides
- middle sized molecules
- salt and water
What is the glucose metabolism function of the kidney?
- gluconeogenesis
- insulin clearance
What is the impact of the loss of the homeostatic function of the kidney?
- increased potassium
- reduced bicarbonate
- reduced pH
- increased phosphate
- salt and water imbalance
What is the impact of the loss of the excretory function of the kidney?
- increased urea
- increased creatinine
- reduced insulin requirement
What is the impact of the loss of the endocrine function of the kidney?
- reduced calcium
- anaemia
- increase parathyroid hormone levels
What is the impact of the loss of the glucose metabolism function of the kidney?
increased cardiovascular risk
What impacts the clinical presentation of kidney failure?
the rate of deterioration
What causes the tachypnoea with normal oxygen and clear lungs on auscultation?
- hyperventilation
- metabolic acidosis
What are the general symptoms of end stage renal failure?
- lethargy
- weakness
- anorexia
- hyperkalaemia
- hyponatraemia
- metabolic acidosis
- raised urea and creatinine
What tends to be the impact of kidney failure on the salt water balance?
reduce secretion of salt and water, which can cause:
- hypertension
- oedema
- pulmonary oedema
What is the impact of tubulointerstitial disorders on the salt water balance?
- damage to the concentrating mechanism
- hypovolemia
- AKI
How can renal failure cause metabolic acidosis?
- reduced hydrogen secretion
- cells take up hydrogen ions, forcing out K+ ions
What is the effect of this acidosis caused by renal failure?
- anorexia
- muscle catabolism
- weight and muscle mass loss
What can cause hyperkalaemia?
- acidosis
- reduced distal tubule potassium secretion
What are the symptoms of hyperkalaemia?
- cardiac arrhythmias
- neural and muscular activities
- vomiting
What are the symptoms of hyperkalaemia dependent on?
chronicity
What ECG changes can be caused by hyperkalaemia?
- peaked T waves
- P wave (broadened, reduced amplitude, or disappears)
- QRS widening
- heart block
- asystole
- VT/VF
What is the impact of reduced erythropoietin?
anaemia
What is the impact of reduced 1-25 vitamin D levels?
- reduced intestinal calcium absorption
- hypocalcaemia
- hyperparathyroidism
What is the impact of phosphate reteintion?
- worsened hypocalcaemia
- leading to increased hyperparathyroidism
What is the major predictor of end stage renal failure?
CKD
What is the major outcome for a patient with CKD?
cardiovascular disease
- arterial calcification
- sudden cardiac death
What is the cardiovascular risk factors with renal failure?
- hypertension
- DM
- lipid abnormalities
- inflammation
- oxidative stres
- mineral/bone metabolism disorder
What is the initial management of kidney failure?
hypovolaemic: IV fluids
hypervolaemic: trial diuretics/dialysis
How do you manage hyperkalaemia?
drive into cells - sodium bicarbonate - insulin dextrose (caution) drive out of body - diuretics/dialysis gut absorption - potassium binders
What are the conservative treatments available for kidney failure?
- erythropoietin injections (anaemia)
- diuretics (oedema)
- phosphate binders
- 1,25 Vit D supplements
(symptom managment)
What are the home treatments available for kidney failure?
- haemodialysis
- peritoneal dialysis/assisted programs
What are the in-centre treatments available for kidney failure?
- haemodialysis (4hr x 3/week)
What is the last line treatment for kidney failure?
transplantation
How does hyperphostate present?
itchiness
What should be avoided in transplantable patients with kidney disease?
- avoid transfusion, can lead to sensitisation and then increase risk of transplant failure
- blood taken from the back of the hand (avoid the antecubital fossa), may be needed in future for dialysis
Is urea an accurate indicator of kidney failure?
- poor indicator
- can be masked by diet, catabolic state, GI bleeding, drugs and liver function
Is creatinine an accurate indicator of kidney failure?
- TREND is helpful
- affected by: muscle mass, age, race and sex
Are radionuclide studies an accurate indicator of kidney failure?
- EDTA clearance…
- reliable but expensive
Is creatinine clearance an accurate indicator of kidney failure?
- difficult for elderly patients to collect and accurate sample
- overestimates GFR at low GFR (small amounts of creatinine is also secreted into urine)
Is inulin clearance an accurate indicator of kidney failure?
- laborious
- used mainly for research purposes
What indicators are used to indicate kidney failure?
eGFR (using CKD epidemiology collaboration)
What impacts the efficacy of the CKD-EPI?
a high/normal eGFR
What must be looked at when suspected kidney failure with normal eGFR/kidney function?
creatinine levels/trends
If a patient is dehydrated, the filtrate present in which part of the nephron will have the highest osmolarity?
Tip of Loop of Henle
What is likely to cause the highest osmolarity?
patient suffering with hepatic cirrhosis
What solute has no effect on ADH production?
urea
Why do most diuretics increase potassium excretion?
The increase in flow rate is detected in the collecting duct and directly stimulates potassium excretion
An athlete after finishing their London Marathon run drank 2L of distilled water. How could you describe their body fluids?
decrease in plasma osmolarity
Sodium excretion is very limited (less than 1% of filtered load) and several mechanisms exist to tightly regulate it. Increasing sodium excretion reduces water retention. Potassium excretion can vary over a very large range (from 1 to 80% of filtered load). Why doesn’t this variability in potassium excretion have a marked effect on water balance?
The amount of potassium in the plasma and extracellular is much lower than the amount sodium so that variations in this amount are insufficient to have a marked effect on water balance.
Mr Holmes (65 years old, 75 Kg) is being treated with a loop diuretic and Mr Smith (66 years old, 74 Kg) with a thiazide diuretic for past 3 weeks (assume that the doses of the respective treatments allow an equivalent inhibition of [Na+] reabsorption). Both the individuals are drinking insufficient but equivalent amount of water. Which of the following statement is likely to be true?
Mr Holmes urine will have lower osmolarity than Mr Smiths.
