CPT2: Renal Flashcards
What are the three classifcations of renal diseases?
- Pre-renal
- Renal
- Post-renal
What is pre-renal disease?
- Reduction in CO or Blood volume
- Problems occuring before the renal e.g. CO problems or ability to perfuse the kidneys
What is renal disease?
- Occurs in the renal structure e.g. Vascular, endothelial, glomerular dysfunction or necrosis
- May be problems with glomerular leaking, scarring, damage to tubing due to abnormal growth/ cells dying
What is post-renal disease?
- Blockage of ureter - kidney stones, infiltrating tumour, prostate
- Can directly or indirectly block. Blockage of tubing leaving the Renal can lead to build up of pressure and damage e.g. unrine infection
What are the 2 classifications based on time periods for kidney diseases?
- Acute kidney injury
- Chronic kidney disease
What is Acute kidney disease?
- Covers a variety of injuries to kidneys from a range of causes
- Often classified by decline in renal excretory function over hours or days
- Rapid change but short time period
- Failure to maintain electolyte, fluid, acid-base homeostasis
What is Chronic kidney disease?
Abnormal kidney function or structure present for more than 3 months, with health implications
What are examples of pre-renal causes and there resepecable causes
- Decreased CO
- Heart failure
- Hypotension
- Myocardial infraction
- operative (operation theatre CO dcr)
- Hypovolemia (loss of volume)
- Sweating
- Haemorrahge - leakage leads to loss of fluid
- Diuretics - dcr fluid volume
- Burns - loss of insulation layer which helps keeps fluid in
- Systemic Dilation
- pharmacological vasodilation - drugs which cause peripheral vasodilartion to CVS effect blood supply tothe kidney
- Sepsis
What is pre-renal damage to the kidney usually caused by? what is this called?
Lack of perfusion (ischaemia) / ocygen to maintain tissues
What are examples of causes of renal failure?
- Afferent/ efferent arterioles
- Tubules
- Glomerulus
What are types of diagnostic imaging and what do these show?
- X-ray and Ultrasound
- Kidney stones
- Cancer
- Kidney size
- Intravenous excretory urogram
- Contrast media to show perfusion
- Structure
- Voiding
- Renal angiogram
- Confirm diagnosis and/ or check renal vascular anatomy
- Biopsies
- Taking renal samples
- Diagnose cause of kidney disease
- GFR/ eGFR
What is the most frequent test for renal function?
GFR
What is clearance?
The volume of plasma cleared of a substance by glomerular filtration through the kidney
What is the equation for clearance? what are each of the parameters?
Cl = (U x V)/ P
CL = clearance
U= Conc of drug/metabolite in urine
V= Rate of urine formation of drug/ metabolite (ml/min)
P= conc of drug/ metabolite in plasma
- How does GFR tend to be measure?
- What is used and why?
- What else can be used?
- What are the disadvantages?
- What are these techniques generally used for?
- Inject inulin
- Inulin isn’t absobed, metabolised, secreted in the renal system
- Radio isotopes and radio-contrast agents
- Time consuming and costly
- Monitoring chemotherapy and evaluation of renal function in living poteital kidney donors
- What is eGFR?
- What substance is used instead and how is it synthesised?
- How is it done
- Disadvantages
- Estinated GFR
- Creatinine - produced by skeletal muscle at rough;y a constant rate so plasma conc depends on rate of excretion by the kidneys
- 2hr urine collection (measures creatinine in urine. Blood samples taken to measure creatinine in plasma. Then equation used.
- Usually Over estimation, time consuming
- What is the name of the equation used to calculate GFR?
- What is the equation?
- Cockcroft and Gault equation
- GFR = (((140-Age) x wt x 1.2)/CrSr (x0.85 if female)))
CrSr = micromol/l
What is creatinine levels effected by?
- Age
- Gender
- Ethnic group
- Muscle bulk
- Diet (protein)
- Maluntrition
- Pharmacology
These variables need to be accounted for so the eqaution altered
What is pratical advice on GRF?
- People from African- Carabean or African backgrounds need a correction factor
- Amputees, body builders (muscle mass extremites), muscle wasting disorders need to interpretate eGFR creatinine with caution
- Don’t eat meat 12hours before
- Blood samples need to be recieved and processed within 12 hours of venepuncutre
What can be used as an alternative to Creatinine?
What/ where is it from?
Cystatin C - peptide syntheises in nucleated cells
What biochemical tests can be carried out and why is this done?
Not enough just to use GFR to determine renal efficacy - need other markers.
- Urea
- Results from protein/ AA breakdown in liver
- Cleared by GFR
- When filtred rates drop, high urea levels rapidly seen in serum
- Electrolytes
- K - Hyperkalemia and hypokalemia
- Ca - Hypercalcaemia
- Na - Hypernatraemia
What can urine results show?
- Protein:
- Bladder infection or kidnehy disease
- less than 150mg/ day
- Haematuria (blood trace)
- White - INfection
- Red - glomerulo-nephritis
- Use reagent strips rather than urine microscopy
- Glucose
- Diabeties
- High due to dietary intake
- Is it normal to find protein in the urine?
- What can be used to meausre protein in urine?
- Only very small amounts of protein are filtered by the glomerulus and are present in the kidney, therefore large amounts of protein found in the urine is a sign of renal disease
- The Alumbin:Creatinine Ratio or the Protein:Creatine Ratio. ACR is prefered and is more accurate/ sensitive in comparision to PCR
Both eGFR and ACR can be used together to analysis renal status
What are the symptoms of CKD?
- If mild to moderate CKD no symptoms normally present
- Usually CKD is diagnosed by eGFR before any sympyoms experienced
- Initally sympyoms are non-specific and vague e.g. tired,lack of energy, just feeling unwell
- Symptoms tends to arise in serve CKD (stage4), e.g.:
- Nausea
- Paleness
- Fluid retention
- Loss of appitite
- Puffiness around eyes
- Need to pass urine more often
- dry and itching skin
- Weight los
- Difficulty thinking
- Muscle cramps
- Also anaemia and imbalance of phosphate, calcium and other electrolytes and pH leading to tiredness and anaemia; bone thining and bone fractures due to calcium and phosphate imbalance
- Stage 5 - end stage is renal failure which is eventually fatal unless treated
What are the main causes of CKD in UK adults?
- Age
- Diabetes
- Hypertension
How does diabetes cause Diabetic kidney disease?
- There is a rise in lipids, glyacted end products and reactive oxygen species. This causes damage to the cells at the glomerulus and disrupts the filter It causes altererations in podocytes, glomerular, vascular and endothelial cell function
Describe high blood pressure in relation to CKD
- High blood pressure is a major cause of CKD, however, CKD can also cause high blood pressure due to the kidney having a role in blood pressure regularion
- Not enough blood flow to kindey means not enough oxygen to maintain kidney tissues causing damage
- Too much blood flow increases blood pressure in kidney/ glomerulus leadnig to damage
Describe ageing in relation to kidney disease
- There is age related decline in kidney function
- In most cases it CKD does not progress beyond the moderate stage unless they develop another problem of the kidney e.g. diabetic kidney disease
What are less common causes of CKD?
- Hypercalcaemia
- Glomerulonephritis (Inflammation of glomerulus)
- Haemolytic-ureamic syndrome
- Renal aretry stenosis (narrowing)
- Toxin-induced or drug induced kidney damage repated kidneyinfection
- connective tissue disease
- Familiar or hereditary disease (polycystic kidney disease)
- Blockage of flow of urine
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How is CKD managed?
- Deal with underlying/ contributory factor (work out why)
- Blood pressure
- Diabetes
- Blockage - unblock
- Medication Review
- Medication:
- Angiotensin converting enzyme (ACE) inhibitor
- Angiotensin II receptor blocker (ARB)
- If stage 3 or worse then people should be immunizied against influenza each year and have a one off immunization against pneumococcus. People wih stage 4 CKD should be immunised against hepatiis B
- Dialysis - removes exces water, toxins and solutes from blood for people who no longer can. Helps with electorlyte balacne
- Transplantation
- Renal protection
- Self management -A greater personal understanding of this long-term condition may improve outcomes but needs to be supported by clear unambiguous information, plus changes in lifestyle and medical interventions. Gets more engaged - take med, changes fluid intake/diet
What are target guidelines for blood pressure for people with and without diabetes. Consider
- Systolic BP
- Diastolic BP
- Target ranges
Dont forget units
Without:
- S - <140 mmHG
- (target - 120 - 139)
- D - <90 mmHG
With:
- S- <130 mmHg
- (target 120 - 129)
- D - <80 mmHG
Describe the use of antihypertensives including:
- What line of treatment are these? What is the benefit?
- Mechanism of aciton
- Examples
- First line - low cost Renin-angiotensin aldosterone system (RAAS) antagonists
- Drugs that work by inhibiting or blocking the RAAS
- ACE inhibitor
- ARB
- Direct Renin inhibitor
- Aldosterone antagonsist
Describe the use of Statins
Atorvastatin 20mg is normally used for prevention of primary or secondary CVS disease for people with CKD
Increase dose if drug doesn’t decrease non-HDL chloesterol by 40% and eGFR is 30ml/min/1.73m2 or more
Discuss with renal specialst for increasing dose if eGFR is less than 30ml/min/1.73m2
Discuss the use of antiplatlets and anticoagulants
- Offer to people with secondary prevention of CVSD
- Be aware ofincreased bleeding risj
Discuss the use of Vitamine D in CKD
- Do not routinely offer VIT D supplements to maintain or prevent CKD-mineral and bone disorders
- Offer colecalciferol or egocalciferol to rat vit D defiiciency in people with CKD snd vit D deficency
Discuss the use of Bicarbonates in people with CKD
- Consider oral sodium bicarbonate supplements for people with both:
- eGFR lower than 30ml/min/1.73m2 AND
- a serum bicarbonate concentration of les than 20mmol/L
What is the prognosis of CKD?
Chronic kidney disease progresses at different rates for individual patients
In general patients in early stages are well managed if able to take on changes to lifestyle, diet , exercise and only a few will progress to stage 4 and 5 where dialysis and transplantation become necessary
Patients are more likely to have more severe health problems associated with cardiovascular disease than with kidney disease
What are the causes of AKI
Same as CKD
What are the managements of AKI
- Deal with obvious cause first: obstruction, infection etc…
- No single drug treatment shown to limit progression or speed recovery
- Review medication and change where necessary
- Control blood pressure, fluids, electrolytes, pH, etc…….
- Control bleeding
- Control nutrition
- Specialist involvement
What are examples of renal failure caused by drugs?
- NSAIDS
- INHIBITION OF PROSTAGLANDIN SYNTHESIS
- VASODILATORY PROSTAGLANDINS REGULATE RENAL PERFUSION
- ØRESULTS IN UN-OPPOSED RENAL VASOCONSTRICTION
- ANGIOTENSIN-COVERTING ENZYME (ACE) INHIBITORS
- PREVENT CONSTRICTION OF EFFERENT GLOMERULAR ARTERIOLE
- UNABLE TO MAINTAIN GLOMERULAR PRESSURE
what are examples of acute tubular necrosis causes?
What are examples of postrenal causes
