AKI and CKD Flashcards
what is GFR
It is the rate at which the glomerulus is filtering the blood to form the filtrate
Which equation is used to estimate creatinine clearance and state its unit
Cockcroft & Gault equation:
CrCl = F(140-age) x weight
—————————
Serum Creatinine
(F = 1.04 in females, F = 1.23 in males)
Units = ml/min/1.73m2
what is creatinine
- It is a chemical waste molecule that is generated from muscle metabolism
- Released into the circulation at a constant rate
- Removed from the circulation by filtration and excreted in urine
Why is it important to check blood creatinine levels?
- Determine sufficiency of kidney function
- Determine severity of kidney damage
- Monitor progression of kidney disease
List FIVE factors that affects creatinine value
- Age
- Exercise
- Gender : Men tend to have higher levels of blood Cr because they have more skeletal muscle tissue than women
- high protein in diet
- Amount of muscle tissue
- malnutrition leading to dramatic weight loss
Another name for Acute Renal Failure is ?
Acute Kidney Injury (AKI)
Name FIVE risk factors EACH for AKI and CKD
AKI
1. Age >75 years
2. Previous AKI
3. Pre-existing CKD
4. Diabetes mellitus
5. Liver disease
6. Heart failure
CKD
Discuss the THREE classifications of AKI, list TWO causes for each classification and a treatment option.
- Pre-renal (75 -80%)
when blood flow to the kidney is reduced
causes:
- Intravascular volume depletion e.g. diarrhoea, vomiting or haemorrhage
- dehydration
- Decreased arterial pressure e.g. heart failure or sepsis
- Nephrotoxic medications e.g. ACEIs, ARBs, NSAIDs
Treatment: hydration with IV fluids
- post-renal (5 -10%)
obstruction in the urinary tract causing urine to build up in kidney
causes :
- kidney stones: mainly occurs in the ureters but may also develop in the urethra
- Benign prostatic hypertrophy
- prostate cancer
- nephrotoxic drugs.
Treatment : refer patient to a urologist
- Intrinsic (10-20%)
Damage to functional tissue of the kidney
causes:
- prolonged hypotension
- nephrotoxic drugs
Treatment :
- Treat the damage…if treatable!
- Hold all nephrotoxic medications
- Adjust doses of all other medications that are prescribed
Describe FOUR complications of AKI and for EACH explain how to manage
- Hyperkalaemia
- AKI causes increase K concentration in blood
- If hyperkalaemia is severe ECG monitoring in is essential
- Acute treatment with Insulin or Salbutamol causes a shift of potassium
- restrict dietary K e.g banana - Acidosis
- when the kidneys can no longer excrete H+ ions causing blood to become acidic
-treat: neutralise blood pH by administering IV sodium bicarbonate - Oedema
when the kidneys ca no longer remove water and Na efficiently
treat :
- Give loop diuretic, Furosemide usually IV at high doses
- monitor serum creatine as there theres risk of worsening pre-renal AKI due to dehydration
- if persistent dialysis
What is creatinine clearance
it is the volume in ml/min of blood plasma cleared of creatine per unit time
Name 5 nephrotoxic drugs and give a rationale why they are regarded nephrotoxic
- NSAID’s (inhibit prostaglandin)
- Diuretics
- ACE inhibitors
- ARB’s
- Amino glycosides
- Contrast dye
- Metformin
they are nephrotoxic because they reducing renal blood flow which causes vasoconstriction (NSAID’s) of afferent blood vessels and vasodilation (ACEI/ AEB) of efferent blood vessels.
in all they reduce eGFR
What is CKD ?
abnormalities of kidney structure or function present for more than 3 months with implications to health
TWO most important things to monitor in CKD patients
Calcium and phosphate levels.
State FIVE risk factors of CKD
- Age and race
- autoimmune disease
- diabetes mellitus
- Hypertension
- kidney stones
- Obesity
- family history of CKD
How does vitamin D levels affect CKD patients
In CKD, the kidneys are less able to make active vitamin D. With less enough active vitamin D, the body absorbs less calcium from food therefore low calcium in blood.
Extra phosphorous in the blood of CKD patients bind to the calcium in the blood, reducing serum calcium.
what are the complications of CKD
- patients being on long-term medications:
- Chronic anaemia
- Hypertension
- Hypercalcaemia
- Pulmonary oedema
- Acidosis
Discuss FOUR imaging techniques used in looking at the kidneys with advantages and disadvantages.
- ultrasound
Advantage
- can pick up structural issues such as tumours or blockages
Disadvantage
- not the most detailed - MRI
advantage
- More sophisticated. Can see details such as visualising blood flow in to the kidney - Computerised Tomography (CT)
disadvantage
- usually need iodinated injection which can be nephrotoxic - Intravenous Excretory Urogram (IVU)
disadvantage
- Uses contrast medium in which some patients are sensitive. - Biopsies
disadvantage
- invasive technique
Name 5 kidney disorders and possible causes
1) Obstructive uropathy : kidney stones
2) Infections : bacteria from GIT. treat with rehydration. Only give antibiotic of patient is symptomatic.
3) Polycystic kidney disease (PKD) : Mainly Inherited
PKD is when theres fluid-filled cyst in kidneys
Tolvaptan : slows progression of cyst
4) Autoimmune diseases :
5) Nephrotic syndrome : as a result of glomerulonephritis (inflammation of the glomerulus)
Kidney stones are also called ‘‘Renal Calculi ‘’. Describe the FOUR types of kidney stones and their causes
- calcium oxalate
- caused by high oxalate diet, dehydration - uric acid stones
- caused when urine is too acidic - cystine stones
- genetic disorder that causes cystine to leak from kidneys to urine - infection stones
happens when there’s UTI
Provide FOUR treatment for kidney stones and why we use them
- Paracetamol or NSAID’s to manage symptoms
- non-invasive
- increase fluid intake to encourage smaller stones to be flushed out
- alpha- adrenergic blockers to relax smooth muscles of the ureter, allowing smaller stones to pass
- Penicillamine used to dissolve cystine stones - Invasive
- ureteroscope
- open surgery
What TWO things would you check in a patient with AKI
Base line creatine
creatine clearance
