Renal Flashcards
What is acute kidney injury?
A significant deterioration in renal function
What causes AKI?
Pre-renal: hypoperfusion (severe drop in BP) - ischaemia, sepsis, drugs, cardiogenic shock
Renal: intrinsic renal disease - glomerulonephritis, infection, drugs
Post-renal: obstruction to urine flow - benign prostatic hyperplasia
How does AKI present?
Oliguria, pulmonary oedema, fatigue, shortness of breath
Hyperkalaemia - medical emergency
How is AKI diagnosed?
Blood: elevated serum urea an creatinine (>50%)
Decrease in urine output
Imaging
How is AKI managed?
Hypovolaemia - give crystalloid for volume replacement
Hypervoleaemia - fluid restriction and diuretics
Treat sepsis, stop NSAIDs, ACEi
Consider gastroprotection (H2 antagonist and PPI)
What is chronic kidney disease?
Irreversible loss of nephrons
What classifies CKD?
GFR <15 is kidney failure
What are some abnormalities of kidney function/structure?
Decreased glomerular filtration rate (GFR)
Increased albuminuria
Urinary sediment abnormalities
Electrolyte and other abnormalities due to tubular disorders
What are some causes of CKD?
Acute renal failure, hypertension, diabetes, kidney disease e.g. PKD
Describe the pathology of CKD
Injury may primarily affect glomeruli or vessels but eventually it leads to reduction in nephron mass with reduction in renal function.
The reduction in nephron mass then causes haemodynamic stress in remaining nephrons, leading to further nephron loss.
How does CKD present?
Early disease is asymptomatic
Loss of appetite, fatigue, bone pain
End-stage renal failure - fluid overload and metabolic derangement (vomiting and diarrhoea)
How is CKD diagnosed?
Bloods - glucose, increased PTH, low calcium
Urine dipstick - albumin:creatinine ratio
Imaging - US for size and to exclude obstruction
How is CKD renal disease progression slowed?
Target to lower blood pressure, offer treatment with renin-angiotensin system antagonist (ACEi)
How are renal complications of CKD managed?
Anaemia: treat underlying cause
Acidosis: consider sodium bicarbonate supplements
Oedema: restrict fluid and sodium intake
CKD bone mineral disorders: give vitamin D supplements
What are the 2 biggest complications of CKD?
CVD due to hypertension, vascular calcification and hyperlipidaemia - patients more likely to die of CVD than need RRT
Renal bone disease (hyper-parathyroid bone disease, osteomalacia and osteoporosis)
What is renal replacement therapy?
Haemodialysis, peritoneal dialysis, haemofiltration
What symptoms of renal failure indicate the need for long-term dialysis?
Inability to control volume status or blood pressure
Acid-base or electrolyte abnormalities
Cognitive impairment
What is haemodialysis?
Blood is passed over a semi-permeable membrane against dialysis fluid flowing in the opposite direction.
Access if via an AV fistula
3+ times a week
What is peritoneal dialysis?
Uses the peritoneum as a semi-permeable membrane. Catheter is inserted into the peritoneal cavity and fluid infused. Solutes diffuse slowly across.
Continuous process with intermittent drainage and refilling at home
What is haemofiltration?
Water cleared by positive pressure, dragging solutes into the waste by convention. The ultra filtrate is replaced with an appropriate volume of clean fluid
What are the complications of RRT?
CVD: increased BP, calcium/phosphate disregulation
Renal bone disease, infection
What immunosuppression is provided at the time of a kidney transplant?
Monoclonal antibodies e.g. daclizumab
What is polycystic kidney disease?
An inherited disorder in which clusters of cysts develop primarily within your kidneys, causing your kidneys to enlarge and lose function over time
What causes polycystic kidney disease?
Inherited mutation in PKD1 gene. Defects in the function of the PKD1 protein lead to cystic change in renal tubules and loss of normal renal tissue
