Chronic Kidney Disease (CKD) Flashcards
How common is it>
1 in 10-50 people have CKD in the UK. CKD is present in 1 in 2 people aged over 75. However less than 1 in 1000 cases of CKD ever require RRT.
What causes it?
- Diabetes – Type II»_space; Type I
- Glomerulonephritis – commonly IgA nephropathy, also rarer disorders eg. mesangiocapillary GN, systemic disorders eg. SLE, vasculitis.
- Unknown – up to 20% in UK have no obvious cause. Many of these present late with small, shrunken kidneys where a biopsy would be uninformative.
- Hypertension or renovascular disease. 5. Pyelonephritis and reflux nephropathy.
Risk factors?
- Diabetes mellitus
- Hypertension
- Cardiovascular disease (IHD, peripheral vascular disease, cerberovascular disease)
- Structural renal disease, known stones or BPH
- Recurrent UTIs or those with childhood history of vesicoreteric reflux.
- Multisystem disorders which could involve kidney (eg. SLE)
- Family history of ESRF or known hereditary disease.
- Opportunistic detection of haematuria or proteinuria.
How does it present?
History
Possible cause – ask about risk factors basically. Systems review – be on lookout for rarer causes, symptoms suggestive of systemic disorder or malignancy.
Current state – uraemic symptoms such as anorexia, vomiting, restless legs, fatigue, weakness, pruritus, bone pain. In women ask about amenorrhoea, in men impotence. If slow onset many patients remain symptomless. Check for oliguria, dyspnoea and ankle swelling.
Examination
- First presentation – look for pallor, uraemic tinge to skin (yellowish), purpura, excoriations, ↑BP, cardiomegaly, signs of fluid overload and possible cause (eg ballotable polycystic kidneys).
Classification
- GFR<15 = Stage 5 CKD.
Investigations?
Blood – HB (normochromic, normocytic anaemia), ESR, U&E, glucose (DM), ↓Ca2+, ↑PO43-, ↑alk phos (renal osteodystrophy), ↑PTH if stage 3 CKD or more.
Urine – Dipstick, MC&S, albumin:creatinine ratio (ACR) or protein:creatinine (PCR) ratio.
Imaging – USS to check size, anatomy and corticomedullary differentiation. In CKD kidneys are usually small (<9cm) but can be enlarged in infiltrative disorders (amyloid, myeloma), APKD and DM.
Histology – Consider renal biopsy if rapidly progressive disease or unclear case and normal sized kidneys.
Treatments?
- Management of patients with CKD can be split into four main approaches:
1. Investigation - Identifying and treating reversible causes – relieve obstruction, stop nephrotoxic drugs, deal with high Ca2+ and CV risk (stop smoking, achieve a healthy weight), tight glucose control in DM.
- Limiting progression/complications - BP – Even a small BP drop may save significant renal function. - Renal bone disease – Check PTH and treat if raised. PO43- rises in CKD, which ↑PTH further and also precipitates in the kidney and vasculature. Restrict diet, give binders to reduce gut absorption. Vit D analogues and Ca2+ supplements reduce bone disease and hyperparathyroidism. - CV Modification – In CKD stages 1 and 2
risk of death from CVD is higher than risk of reaching ESRF. Give statins to those with raised lipids. Give apirin also. - Diet – Should be reviewed by a dietician for healthy, moderate protein diet, K+ restricted if hyperkalaemic, and avoidance of high phosphate foods (eg milk, cheese, eggs) - Symptom control - Anaemia – Check haemianitics and replace iron/B12/folate if required. If still anaemic consider recombinant human EPO. If Hb falls despite this, suspect red cell aplasia (anti-EPO Ab) and get help from haematology. - Acidosis – consider sodium bicarbonate supplements for patients with low sodium bicarb, improves symptoms and progression of CKD. Caution in patients with hypertension, as sodium load can ↑BP. - Oedema – high doses of loop diuretics and restriction of fluid and sodium intake. - Restless legs/cramps – check ferritin (low levels worsen symptoms), clonazepam or gabapentin may help. Quinine sulphate can help with cramps.
- Preparation for renal replacement therapy
