Renal Flashcards
How is AKI diagnosed?
Serum creatinine levels
What is the diagnostic criteria for AKI?
Rise in creatinine > 25micromol/L in 48h
Rise in creatinine > 50% in 7d
Urine output < 0.5ml/kg/h over 6h
List risk factors for AKI
> 65y
Sepsis
CKD
HF
Diabetes
Liver disease
Cognitive impairment- Decreased fluid intake
Medications (NSAIDs, gentamicin, diuretics and ACE-is)
Radiocontrast agents (CT scans)
List pre-renal causes of renal impairment
Insufficient blood supply to kidneys reducing filtration of blood
- Dehydration
- Shock (septic or acute blood loss)
- HF
List renal causes of renal impairment
Intrinsic disease in kidneys
- Acute tubular necrosis
- Glomerulonephritis
- Acute interstitial nephritis
- HUS
- Rhabdomyolysis
List post-renal causes of renal impairment
Obstruction to outflow of urine
- Kidney stones
- Tumours
- Strictures of ureters or urethra
- BPH
- Neurogenic bladder
What is acute tubular necrosis?
Damage and death of epithelial cells of renal tubules
What are the causes of acute tubular necrosis?
Ischaemia due to hypoperfusion (dehydration, shock, HF)
Nephrotoxins (gentamicin, radiocontrast, cisplatin)
What is seen on urinalysis in acute tubular necrosis?
Muddy brown casts
Renal tubular epithelial cells
What is the prognosis of acute tubular necrosis?
Epithelial cells regenerate = Reversible
Recovery in 1-3wks
What does urinalysis +ve for protein and blood suggest?
Acute nephritis
How to test for obstructive cause of AKI
US
Outline management of AKI
IV fluids
Withhold meds that worsen condition- NSAIDs, ACE-is
Withhold meds that may accumulate with reduced renal function- Metformin and opiates
Catheter if obstruction
Dialysis if severe
List complications of AKI
Fluid overload, HF, pulmonary oedema
Hyperkalaemia
Metabolic acidosis
Uraemia (high urea)- Can lead to encephalopathy and pericarditis
Define CKD
Chronic reduction in kidney function sustained over 3mths- Permanent and progressive
List causes of CKD
Diabetes
HTN
Meds- NSAIDs or lithium
Glomerulonephritis
PKD
Outline presentation of CKD
Fatigue
Pallor (anaemia)
Foamy urine (protein)
Nausea
Loss of appetite
Pruritis
Oedema
HTN
Peripheral neuropathy
What is eGFR based on?
Serum creatinine
Age
Gender
What is GFR?
Rate at which fluid is filtered from blood into Bowman’s capsule
How do you quantify proteinuria?
Urine albumin : Creatinine ratio (ACR)
Outline diagnostic criteria of CKD
eGFR sustained below 60mL/min/1.73m2
Urine ACR sustained above 3mg/mmol
Outline G score
Based on eGFR- Marker of CKD
- G1>90
- G2 60-89
- G3a 45-59
- G3b 30-44
Outline A stage
Based on ACR- Marker of CKD
- A1 <3mg/mmol
- A2 3-30mg/mmol
- A3 >30mg/mmol
What is accelerated progression in CKD?
Sustained decline in eGFR within 1yr of either 25% or 15mL/min/1.73m2