CKD Flashcards
Define CKD
CKD is longstanding, usually progressive, impairment in renal function (haematuria, proteinuria or anatomical abnormality) for more than 3 months
Define CKD in terms of GFR
Defined as a GFR < 60mL/min/1.73 m2 for more than 3 months with/without evidence of kidney damage (haematuria, proteinuria or anatomical abnormality)
What are the three main causes of CKD
Diabetes mellitus, Kidney diseases and Hypertension
Briefly describe the pathophysiology of CKD
Fewer functioning nephrons –> hyperfiltration of remaining nephrons –> glomerular hypertrophy –> increased pressure and stress –> damage is remaining nephrons
What is angiotensins role in the progression of CKD
Disrupts mesangial cells - which then lay down extracellular matrix in response to inflammation. Also stimulate TGF beta which adds to extracellular matrix accumulation. And stimulates PAI-1 so no proteolysis of matrix = excessive matrix and scarring in both the glomeruli and instistitum
What are the risk factors for CKD?
- Diabetes mellitus
- Hypertension
- Old age
- CVD e.g. ischaemic heart disease, peripheral vascular disease etc.
- Renal stones or benign prostatic hyperplasia (BPH)
- Recurrent UTI’s
- SLE
- Proteinuria
- AKI
- Smoking
- African, Afro-Caribbean or Asian origin
- Chronic use of NSAIDs
What is the epidemiology for CKD?
- More common in females
- Risk increases with age
Why are early stages of CKD often asymptomatic?
The Kidneys have a lot of reserve and symptoms aren’t common until the serum urea concentration exceeds 40mmol/L but many patients develop uraemic symptoms at lower levels of serum urea
What are the symptoms of CKD?
- Malaise
- Anorexia and weight loss
- Insomnia
- Nocturia and polyuria (>40ml/kg/24hours) due to impaired concentrating ability
- Itching
- Nausea, vomiting and diarrhoea
- Symptoms due to salt and water retention - peripheral or pulmonary oedema
- Amenorrhea in women and erectile dysfunction in men
What investigations would you do if you suspect CKD?
- ECG
- Urinalysis
- Urine microscopy
- Serum biochemistry
- Bloods
- Immunology
- Imaging
- Biopsy
Why would you perform an ECG in CKD?
Check for arrythmias due to hyperkalemia
Why would you test for auto-antibodies in CKD?
- Screening for SLE, scleroderma and Goodpastures
- Hep B, C, HIV and streptococcal antigen tests
Why is anaemia a complication associated with CKD?
Kidneys produce EPO so with reduced kidney function –> decreased EPO production –> normocytic anaemia
Why is renal osteodystrophy a complication associated with CKD?
Renal phosphate retention and impaired 1,25-dihydroxy vitamin D production lead to a fall in serum Ca2+ and thus a compensatory increase in PTH which can result in skeletal decalcification leading to bone disease
What skin disease is associated with CKD?
Pruritus due to nitrogenous waste products of urea - may be scratch marks
