Chronic kidney disease Flashcards
Define CKD
Reduction in kidney function or structural damage (or both) present for >3 months, with implications for health.
Causes of CKD
Diabetes - most common Hypertension Glomerular disease PKD Pyelonephitis Other e.g. nephrotoxic drugs, toxins, SLE, vasculitis, myeloma, HIV
Consequences + complications of CKD
AKI
Anaemia (reduced EPO production)
Hypertension (increased renin due to falling GFR)
Osteodystrophy (low calcium due to not activating vit D, causes PTH release and so bone resorption –> secondary hyperparathyroidism)
Hyperkalaemia (kidneys normally excrete potassium)
Azotemia (high urea)
Dyslipidaemia Cardiovascular disease Peripheral neuropathy and myopathy Malnutrition Malignancy End-stage renal disease All-cause mortality
Signs/symptoms/consequences of high urea
Nausea and loss of appetite
Encephalopathy - asterixis, coma, death
Pericarditis
Bleeding (urea makes platelets less sticky), Uremic frost (crystals deposit in skin)
How does hypertension lead to CKD?
Walls of artery supplying kidney become narrow
- -> less blood + oxygen to kidney
- -> ischaemic injury to glomeruli
- -> Immune cells (macrophages and foam cells) secrete growth factors
- -> mesangial cells secrete extracellular matrix
- -> glomerulosclerosis
- -> nephrons have diminished ability to filter blood
How does diabetes lead to CKD?
Excess glucose
- -> non-enzymatic glycation
- -> efferent arteriole becomes stiff and narrow
- -> more difficult for blood trying to leave glomerulus
- -> increased pressure within glomerulus, causing hyperfiltration
- -> mesangial cells produce more and more matrix
- -> glomerulosclerosis
- -> nephrons have diminished ability to filter blood
CKD should be diagnosed in people with…?
1) Markers of kidney damage e.g. urinary albumin:creatinine ratio (ACR) >3 mg/mmol, urine sediment abnormalities, electrolyte and other abnormalities due to tubular disorders, abnormalities detected by histology, structural abnormalities detected by imaging, and a history of kidney transplantation
AND/OR
2) A persistent reduction in renal function
e. g. eGFR <60
What to ask in history?
PC/HPC - lethargy, itch, SOB, cramps, sleep disturbance, bone pain, loss of appetite, vomiting, weight loss, taste disturbance
ROS - urine output, mood
PMH - previous AKI, risk factors for CKD, previous CVD/stroke
DH - any nephrotoxic drugs?
FH - renal disease e.g. ADPKD
SH
Signs of CKD on examination
Uraemic odour (ammonia-like smell of the breath, may be present in advanced disease).
Pallor
Cachexia
Cognitive impairment
Dehydration or hypovolaemia
Tachypnoea (fluid overload, anaemia, or co-morbid ischaemic heart disease)
Hypertension
Palpable bilateral flank masses with possible hepatomegaly (polycystic kidney disease)
Palpable distended bladder (obstructive uropathy)
Peripheral oedema (renal sodium retention, hypoalbuminaemia, or co-morbid heart failure)
Peripheral neuropathy or myopathy
Frothy urine (may indicate proteinuria)
Define G1
eGFR >= 90
Define G2
eGFR 60-89
Define G3a
eGFR 45-59
Define G3b
eGFR 30-44
Define G4
eGFR 15-29
Define G5
eGFR <15