Chronic kidney disease
Chronic kidney disease used to be known as chronic renal failure. They changed the classifications and have thus changed the name. Which is annoying.
Definition
The permanent, progressive loss of kidney function.
Epidemiology
Pathophysiology
Basically, there's some sort of disease of the kidney that just doesn't go away. The most common culprits are:
- glomerulonephritis (25%)
- multisystem disease (e.g. diabetes)
- pyelonephritis/tubulointerstitial disease
- hypertension
- polycystic kidneys
- idiopathic (15%)
All these things are bad for kidneys. Mainly, because they can cause chronic kidney disease. Don't get them if you like your kidneys. (Hint: you should enjoy your kidneys - they're handy).
Risk Factors
These are risk factors that qualify you for testing in primary care so they'll do for a list of important risk factors:
- diabetes
- hypertension
- cardiovascular disease
- structural kidney disodres, renal calculi, prostatic hypertrophy
- multisystem disease with kidney involvment (e.g. SLE)
- FHx
- haemturia or proteinuria
Clinical Features
Basically there's loads of potential features of CKD so they're split up by system.
- GI - nausea, vomiting, diarrhoea and anorexia
- CVS - hypertension, peripheral vascular disease, heart failure and uraemic pericarditis
- Neuro - CNS: coma, confusion, fits; and peripheral neuropathy
- Haematological - anaemia: pallor, lethargy, breathless on exertion; and platelet abnormalities: epistaxis, bruising
Investigations
Primary Care: early identification
Basically use eGFR (estimated glomerular filtration rate) and ACR (albumin: creatinine ratio). There's loads of specifics for people with diabetes and without diabetes that I can't be bothered to do now. I will at some point...
Secondary Care
Bloods
- FBC - anaemia
- ESR -
- eGFR
- Glucose - diabetes
- Uric acid - diabetes, cardiovascular disease
- bone profile
- calcium↓
- phosphate↑
- alkaline phosphatase↑ (aka alk phos)
Management
There are lots of general things that you need to do for all people with CKD. Firstly, regular monitoring is really important. That means doing lots of blood tests and figuring out the eGFR on a regular basis and seeing how it's changed. General health stuff like telling them to do exercise, not smoke and eat healthily will all help. Limit sodium intake is also important - don't go caning the salt when you get chips and be very aware of how much you're taking in. But then there's other more medical stuff too:
- Avoid nephrotoxins: IV radiocontrast agents, NSAID, aminoglycosides
- Cardiovascular: consider aspirin, statins and above all control hypertension if they have it.
- ACE inhibitor if: urine PCR >100mg/mmol; diabetes and microalbuminuria; creatinine and potassium should be checked following therapy initation - look for creatinine rise after two weeks (renal artery stenosis) and hyperkalaemia.
Stage 3 Management
Further up the stages, there's more stuff that needs doing. You need annual monitoring of haemoglobin, potassium, calcium and phosphate. Make sure you do a USS if: lower urinary tract symptoms, hypertension w/o secondary cause, unexpected fall in GFR. Immunise against influenza and pneumococcus. Review medications and don't give NSAIDs and check hyper- and hypoparathyroidism.
Stage 4-5 Management
Refer - everything should be discussed with renal physicians. Seen 3 monthly for creatinine, Hb, calcium, phostphate, bicarb, parathyroid hormone. Diet needs assessing and immunise against hepatitis B. Correct phosphate problems and any hyperparathyroidism as well as correcting acidosis.
Dialysis where necessary and remember to do all the above stuff where appropriate as well.