Kidney disease 1 Flashcards
What are the functions of the kidney?
- regulation of bone metabolism
- regulation of red blood cell production
- regulation of blood pressure
- influence on blood pH and acid-base-metabolism
- excretion of metabolic waste products and water
Describe the range of renal patients
“Normal” renal function
Patients with various stages of impairment
Patients not yet having dialysis (pre-dialysis) but rapidly approaching
Patients requiring Renal Replacement therapy
Haemodialysis
Peritoneal dialysis
Transplantation
CKD: what is it? How common is it?
What is moderate to severe CKD associated with?
Treatment goals?
- Abnormal kidney function and/or structure
- Common
- Often unrecognised but often exists with other conditions eg diabetes or cardiovascular disease
- Moderate to severe CKD associated increased risk of other adverse outcomes
- Not all CKD progresses to end-stage kidney disease
It is detectable and easily tested
Treatment can prevent or delay progression and reduce complications
State markers of kidney disease
Albuminuria (ACR >3mg/mmol) Urine sediment abnormalities Electrolyte and other abnormalities due to tubular disorders Abnormalities in histology Structural abnormalities (imaging) History of kidney transplantation
GFR
What is it?
Normal value?
Indicative of?
- Glomerular filtration rate is the best measure of overall kidney function
- It is the composite function of all the nephrons
- -Normal ~100mls/min
- Result roughly indicates % of normal function
- Exact measurement difficult but can be estimated in the lab from serum creatinine, gender and age using a simple formula.
Creatinine-estimated GFR versus
NICE guidance
-Laboratories should report an estimate of GFR using a prediction equation and the serum creatinine
-Laboratories should use the Chronic Kidney Disease Epidemiology collaboration (CKD-EPI) creatinine equation to estimate GFRcreatinine
-Apply a correction factor for patients of African-Caribbean or African family origin ((eGFR x 1.159)
In extreme muscle mass
-decreased muscle mass will lead to overestimation and increased muscle mass under estimate GFR
Cystatin C-based GFR
What is it? When is it used?
-Laboratories report an estimate of GFR eGFRcystatinC and the serum cystatin C
-Used when an improved assessment of risk is needed
-Caution in patients with uncontrolled thyroid disease
-Used at initial diagnosis to confirm or rule out CKD in people with:
An eGFRcreatinine of 45-60ml/min/1.73m2 for >90 days and
No proteinuria or other marker of kidney disease
Urine dipstick tests
What are they? What do they detect?
What are they associated with?
- Basic test to shows kidney damage (presence and severity)
- Haematuria (blood in urine)
- Associated with more rapid decline in kidney function
- Proteinuria/ albuminuria (protein in urine)
- Ratio of protein or albumin to creatinine is measured.
- ACR recommended for people with diabetes
What is CKD? Prevalence?
What can it result in?
What complications can it cause?
Estimated to affects about 10% of the general population
Long term, often progressive loss of normal kidney function
May, (but does not always) result in end-stage kidney failure
Usually asymptomatic until renal function severely reduced
Commonly leads to cardiovascular disease (CVD) and other complications
As kidney function deteriorates, the incidence of complications increases eg anaemia, CVD, disordered bone mineral metabolism and calcification of blood vessels.
Risk factors for CKD (clinical conditions)
Diabetes Systemic Hypertension Acute kidney injury Cardiovascular disease Structural renal tract disease, recurrent renal calculi, prostatic hypertrophy Multisystem disease with potential kidney involvement, eg SLE Family history of end stage kidney disease Detection of haematuria Proteinuria Dyslipidaemia Smoking Obesity Alcohol consumption Low socio-economic status Drugs and herbs/analgesic abuse auto-immune disease/obstructive uropathy/stones
Unmodifiable risk factors for CKD
- old age
- male sex
- race/ethnicity
- genetic predisposition
- family history
- low birth weight
Clinical disease causes of CKD
Diabetes
Chronic (untreated) high blood pressure.
glomerulonephritis (inflammation of the kidney)
pyelonephritis (infection in the kidney)
polycystic kidney disease (an inherited condition where both kidneys are larger than normal due to the gradual growth of masses of cysts)
failure of normal kidney development in an unborn baby while developing in the womb
systemic lupus erythematosus (a condition of the immune system where the body attacks the kidney as if it were foreign tissue)
long-term, regular use of medicines, such as (non-steroidal anti-inflammatory drugs (NSAIDs), including aspirin and ibuprofen
blockages, for example due to kidney stones or prostate disease
Discuss the importance of early detection of CKD
Early detection of CKD and its complications can delay or prevent progression to ESRD
Early intervention
Blood pressure control
Glycaemic control for diabetes
Reduce proteinuria
Control of rate of kidney disease progression via:
Blood pressure
Drugs
- Ideally, blood pressure reading should be systolic below 140mmHg Target range 120-139mmHg) and diastolic below 90mmHg
- kidney disease, diabetes or a condition that affects heart and circulation, target blood pressure should be below 130/80mmHg.
- 3 or more anti-hypertensives usual
Choice of anti-hypertensive in CKD
Combinations not recommended
Monitoring requirements
Choice of agent:
Low cost renin angiotensin antagonist
Do not use combination of ACE and ARB
ACE inhibition/ A2RB/aldosterone blockade
Lower Bp, reduce proteinuria, preserve renal function
Measure serum potassium and estimate GFR before starting
Repeat after 1-2 weeks
Do not give if potassium >5mmol/l pre treatment
Stop if potassium on treatment is >6mmol/l
