Renal Flashcards
What are the two types of renal disease?
Acute - rapidly progressive and reversible
Chronic - progressive and irreversible loss of renal function
What is renal insufficiency?
renal function decline to 25% of normal GFR
What is renal failure?
significant loss of renal function with <10% remains end stage renal failure
what is uremia?
it is a renal failure syndrome due retention of toxic waste and deficiency state.
High blood urea and Cr levels
what are the symptoms of uremia?
fatigue
nausea
anorexia
vomiting
what is azotemia?
High serum levels and Cr which are caused by Renal failure and Renal insufficiency
what does Uremia + Azotemia =
accumulation of nitrogenous waste in the blood
What is Acute Kidney Injury (AKI)?
- It is rapid decline in renal function (hrs/days).
- Failure to maintain fluid, electrolyte and acid base homeostasis
What is Oliguria?
passing small volume of urine
< 30ML/400ML per 1hr/day)
How is AKI diagnosed?
High conc of urea and Cr
Why does Blood urea nitrogen (BUN) increase?
if the GFR decreases due to renal disease or decreased blood flow to the kidney then BUN increases
What is the normal range of Blood Urea Nitrogen (BUN)?
2.5-6.6 mmol/L
There are two biochemical tests. Name and describe them.
Metabolic acidosis - inability to excrete H+
Hyperkalaemia - impaired excretion of K+. The low threshold of initiation of action potential disturbs electrical conduction of the heart which results in cardiac arrest.
There are 3 classifications of AKI; Pre-renal, Post renal and intra renal. What is Pre renal?
- Heart failure
- Blood/fluid loss
- Drugs (ACEIs, ARBs etc)
What falls under post renal classification?
obstruction of urinary tract
- stones
- tumors
what falls under intra renal classification?
renal parenchymal injury
If a patient is suspected to have an AKI, what clinical investigations need to be carried out?
Full history, physical examination, urine examination, blood examination and radiological
What happens to a patient who has oliguria, acute tubular necrosis has supervened and the plasma urea/Cr/K+ levels are rising?
DIALYSIS
What are the symptoms of AKI?
nausea/vomiting, dehydration. fatigue, decreased frequency of urinating and change in urine colour.
What are the risk factors of AKI?
- > 65 years
- AKI history
- Chronic conditions such as HF, HPT and diabetes
What is Creatinine Clearance (CrCL) and what is it used for?
the indirect measure of GFR and renal blood flow and it is used to monitor changes in chronic renal function.
amount excreted = amount filtered
What is creatinine?
end product of muscle metabolism
What is the normal Cr Clearance level?
Male = 64-111 Female = 50-98
lower in females
Describe the RIFLE staging of AKI.
Risk of renal dysfunction - 50% increase in Cr and > 25% decrease in GFR
Injury of kidney - 2 fold increase in Cr and >50% decrease in GFR
Failure of kidney function - 3 fold increase in Cr and >75% decrease in GFR
Loss of kidney function - loss of kidney function for 1-3 months
End stage renal failure - loss of kidney function for <3 months
State the intercellular and extracellular concentrations of K+ distributions.
IC - 140-150 mmol/L
EC - 3.5 - 5.0 mmol/L
What are the 2 mechanisms involved in mechanism K+ regulation?
- Conserve/ eliminate K+
2. Transcellular shift between intercellular and extracellular fluid
What does abnormal K+ cause?
Hypokalaemia and/or Hyperkalaemia
What is hypokalaemia? What is it due to?
It is a decrease in plasma K+ (<3.5mmol/L)
This is due to:
- low intake of K+ in diet
- excess renal, GIT and skin losses
- Redistribution between intercellular fluid and extracellular fluid compartments
What is hyperkalaemia? What is it due to?
It is increase in plasma K+ (>5.0 mmol/L)
This is due to:
- Decrease in renal elimination
- Excess rapid admin
- Movement of K+ from the intercellular fluid to the extracellular fluid compartment
What is chronic kidney disease (CKD)?
Decrease in kidney function and/or structural damage for more than 3 months and the GFR is more than 60mL/min.
What are the risk factors of Chronic kidney disease?
Diabetes, HPT, CVD, 50 yrs+, BMI, smoking, alcohol and family history of S5 chronic kidney disease
What are the causes of Chronic kidney disease?
- Decrease in renal perfusion which results in hypotension due to drugs, poor cardiac function
- UTI/UT obstruction
- Nephrotoxic meds - ACEIs, metformin
How is a diagnosis of chronic kidney disease reached?
- Blood test - serum Cr and GFR levels
- Morning urine sample to measure Albumin:Cr ratio (the higher the more sever)
- Dipstick test for haematuria
What are the stages of Albumin : Cr ratio?
A1 - less than 3mg/mmol - normal to mid
A2 - 3-30mg/mmol - moderate
A3 - more than 30mg/mmol - severe
What are the investigations carried out on a patient with suspected chronic kidney disease?
Medical history
Physical examination
Tests: biochemistry, immunology, radiology, biopsy
What would the blood test results of a patient with chronic kidney disease show?
- Increase in urea, Cr and PO4- levels
- Decrease in Ca2+ and Hb
What are the symptoms of chronic kidney disease?
Fatigue, Nausea, anorexia and weight loss
If a patient has S4/5 chronic kidney disease, what would they present with?
- hyperkalaemia
- uraemia
- anaemia
- impaired Vit D
In relation to CKD. What is the mechanism of action of loop diuretics?
increase urine volume and Na+ excretion
In relation to CKD. What is the mechanism of action of Acetazolamide?
Treat metabolic acidosis due to renal failure
In relation to CKD. What is the mechanism of action of ACEIs/ARBs?
To control HPT and decrease the rate of decline of renal function
In relation to CKD. What is the mechanism of action of Antiemetics?
control nausea and vomiting with renal failure
In relation to CKD. What is the mechanism of action of Erythropoietin?
Treat anaemia as it stimulates red cells production
In relation to CKD. What is the mechanism of action of increasing CaCO3/Al2OH3 and decreasing PO4- in diet intake?
hyperphosphataemia control
Describe Haemodialysis
Done through the artery in the arm.
- efficient
- 4hours, 3 times a week
- 2-3 days between treatment
- at hospital
- Strict diet + fluid restrictions between treatments
- vascular related infections may occur
- Patient must depend on others
Describe Peritoneal Dialysis
Done in the gut
- Less efficient
- 4 treatments a day for 30-60 mins
- hours between treatments
- at home
- less restrictions
- peritonitis and catheter related infections may occur
- patient is independent for treatment
When should a renal transplant not be considered?
Patient has:
- severe heart or vascular disease
- active malignancy
When should a renal transplant be considered?
If the patient:
- under 1 year or Over 75 years
- High risk of disease recurrence
- significant comorbidity
- lower urinary tract disease
What is Acute pylenephritis?
Infection of Upper UT of renal parenchyma and pelvis
What are the symptoms of Acute pylenephritis?
rapid onset, fever, chills, nausea, urinary frequency
Why does Acute pylenephritis affect women more than men?
Women have a shorter urethra therefore bacteria can enter bladder more easily
What is Chronic pylenephritis?
Progressive infection of the upoper UT - scarring and deformation of renal calyces and pelvis
