CKD Flashcards
causes and diagnosis of adult polycystic kidney disease?
Diagnosis: Cysts grow with age, generally presents in adulthood (unless FH and screened)
Diagnoses with ultrasound
Genetic testing (expensive)
Prognosis depends on rate of increase in kidney size and age
Cause:
Mutation in either PKD 1 gene (85%) - earlier disease
Or PKD 2
Clinical disease in adult polycystic kidney disease
Cysts fluid filled and can cause secondary complications e.g. pain, bleeding into cyst, infection, renal stones/ stasis
Hypertension v common prior
Rate of decline variable
Increased incidence of intra-cranial aneurysms/ heart valve abnormalities
Management of adult polycystic kidney disease
Treat hypertension - block RAAS
Diet:
Fluids, low salt, normal but not excessive protein
Tolvaptan (new, vasopressin 2 receptor antagaonsit) ❌urinary frequency
Stages of CKD
1 - kidney damage with normal/ high GFR - GFR _>90
✅underlying condition and comorbidities
2 - mild, GFR 60-90
✅estimate rate of progression
3 moderate
a - GFR 45-59 (don’t automatically progress)
b - 30-44
✅ evaluate and treat complications
4 - severe, GFR 15-29
✅ prepare for renal transplant therapy
5- kidney failure, GFR <15 or dialysis
✅dialysis or transplantation if uraemia
Also albuminuria categories:
1 <30mg/g
2 30- 299 mg/g
3 _>300 mg/g
Definition of CKD
Irreversible and sometimes progressive loss of renal function over months- years
Renal injury causes renal tissue to be replaced by extracellular matrix in response to tissue damage
Causes of CKD
Diabetes - 45%
Hypertension - 33%
Immunologic - glomerulonephritis 10%
Infection - pyelonephritis
Genetic - adult polycystic kidney disease
Obstruction and reflux nephropathy
Vascular
Systemic diseases e.g. myeloma
what to consider in the Management of CKD
Define degree renal impairment, cause of renal impairment, diagnosis and prognosis, identify complications, plan long term treatment (delay progression and plan for dialysis and transplantation)
Always measure:
Blood pressure and urine dipstick
When is eGFR not appropriate?
Only accurate in adults, correction needed off black ppl
Not useful for AKD (intercurrent illness or haemodynamic problems) or pregnant ppl
Investigations CKD
Always measure:
Blood pressure and urine dipstick
Blood test - urea and electrolytes, bone biochemistry, liver function tests (albumin), FBC, CRP
+/- iron levels (ferritin, iron, reticulocyte Hb)
+/- PTH
If there is clinical suspicion of the following:
Auto-immune disease = auto-antibody screen/ complement levels
Vasculitis = Anti-neutrophil cytoplasmic antibody
Myeloma = serum immunoglobulin screen/ protein electrophoresis and serum free light chain measurement
Stones/ mass = CT scan
Mass = MRI scan
Renal artery stenosis = MR angiogram
USC - kidney size, obstruction
Kidney biopsy - unknown cause, haematuria/ proteinuria
Prevention and delaying progression of CKD
Modifiable risk factors: Lifestyle Smoking Obesity Lack of exercise
Control diabetes
Control hypertension 80-85% - ACE inhibitors / angiotensin receptor blockers, diuretics, fluid restriction unless high risk of hypovalaemia
Proteinuria
Lipids
Why do CKD patients often get nocturia?
Small glomerular filtrate but same solute load causes osmotic diuresis (reduced max concentrating ability and response to ADH)
Why do CKD patients often get hyperkalemia?
Can occur once eGFR <20mls/ min, less likely when good urine output maintained
May require:
- stopping ACE inhibitor/ angiotensin receptor blocker
- avoidance of other drugs that can increase K+ (amiloride, spironolactone, trimethoprim)
- altering diet to avoid food with high K+
Why do CKD patients often get acidosis? Symptoms
metabolic acidosis include:
impaired ammonia excretion,
decreased tubular reabsorption of bicarbonate,
insufficient production of bicarbonate
Symptoms:
Headache, coma, dyspnoea, arrhythmia, nausea, diarrhoea, seizures
✅NaHCO3 tablets
Causes of anaemia in CKD, how to treat
Decreased erythropoietin, iron deficiency (malnutrition and poor absorption), blood loss, short RBC lifespan, co-morbidities, bone marrow suppression, Medication, deficiency VB12 and folate, high hepcidin level, inflammation, infection
✅
- Always check iron stores first
- If iron low replace iron (oral/ IV)
- Re-check Hb
- Hb still low start erythropoietin stimulating agent (ESA/ EPO) 🤑
Aim: Hb 100g/L - 120
How does CKD lead to mineral bone disease?
ImpIred renal function -> decreased alpha-hydroxylase (converts non-active VD to calcitriol) -> impaired mineralisation of bone -> increased bone resorption -> increased PTH -> increases osteoclastic activity and bone resorption ->
stimulations of parathyroid glands leading to hyperplasia
