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CHRONIC
KIDNEY DISEASE
(CKD) Chronic kidney disease, or
reduced kidney function, is extremely common and usually associated with no
symptoms at all until it is in its very advanced stages. Kidney function declines with
age, reducing by around 1% each year from the mid 30s. Kidney disease is
detected by the persistent presence of protein in the urine and a reduced eGFR
(effective glomerular filtration rate how much blood/urine is filtered by
the kidneys each minute). eGFR is
assessed routinely on a common biochemistry blood test it takes into account
the blood creatinine level and the age and gender of the person. There are a
number of factors which have an effect on the result (including dehydration,
race, muscle mass etc) and which need to be taken into account when evaluating a
result. In adults less than 70 years of age an eGFR persistently less
than 60 ml/min reflects early kidney disease, particularly if there is also
raised protein levels in the urine. An eGFR less than 30 ml/min is an indication
of severe CKD. The most
common causes of CKD are *diabetes, chronic glomerulonephritis,
hypertension and polycystic kidney disease (polycystic kidneys and some forms of
glomerulonephritis are inherited). -
age more than 50 years -
diabetes -
hypertension -
smokers -
obesity -
family history of CKD -
ATSI background The complications and treatment
goals for CKD, heart disease and diabetes are very similar. The most important
treatment strategy to slow the progression of CKD is to reduce blood pressure to
quite low levels. Management Goals for CKD 1 Control Blood Pressure
goal BP < 130/80 or < 125/75 if diabetic or there is significant
protein in the urine (more than 1gm/24 hours). Using an ACE or ARB
medication is usually advised as these have a renal protective effect as well as
reducing blood pressure. 2 Reduce Protein in urine
using blood pressure reducing strategies 3 Control Cholesterol
goal total cholesterol < 4 mm, LDL cholesterol < 2.5 mm 4 Excellent control of
Diabetes HbA1c < 7 5 Cease Smoking 6 Weight Control BMI
< 25 7 Regular Exercise
30 minutes walking per day 8 Low Salt Diet 9 No more than 1-2 Alcohol
drinks per day 10 Annual influenza vaccine
(and Pneumovax immunisation) In more advanced stages of CKD other
complications often arise, including -
anaemia -
mineral and bone disorders, including high phosphate levels
and secondary hyperparathyroidism -
high potassium levels -
restless leg syndrome (very common) -
sleep apnoea -
depression -
general itching -
loss of appetite and nausea -
frequent voiding during the night -
secondary gout These complications require
specific dietary modifications and medication. Medication
and CKD Many medications are excreted
from the body by the kidneys and when the kidneys are not functioning adequately
these medications can accumulate in the body and have adverse effects. These
medications either have to be taken in a reduced dose or avoided altogether in
CKD, especially when it is more advanced. The more common include: -
some diabetic medications : sulfonylureas, metformin,
glibenclamide, glimepiride (Glimel) -
Allopurinol and colchicine gout treatments -
*Anti-inflammatory medications for arthritis -
Digoxin -
Beta blockers : sotalol and atenolol ( metoprolol is an
alternate) -
*Radiographic contrast media -
*Lithium -
Gabapentin -
*Aminoglycosides including Gentamicin -
Antivirals (Zovirax, Famvir, Valtrex) -
Diamox -
*Combination of NSAID anti-inflammatory + diuretic + ACE *
these medications can cause further kidney damage. |