Acute Kidney Injury Flashcards
(49 cards)
Definition of acute kidney injury?
Sudden acute drop in kidney function
How is acute kidney injury diagnosed?
Measuring serum creatinine
What is AKI characterized by?
-Rapid increase in blood urea & creatinine concentration caused by decreased glomerular filtration rate
Criteria for AKI?
- Rise in creatinine of >26.4micromol/L in 48 hours
- Rise in creatinine of >50%
- Urine output of <0.5ml/kg/hour for more than 6 hours
Who can commonly get AKI?
Common for patients already in hospital
Risk factors for AKI?
- CKD
- Heart fialure
- Diabetes
- Liver diseasse
- Older age (>65)
- Cognitive impairment
- Nephrotoxic medications: lithium, haldol
Classifying causes of acute renal injury?
Pre-renal
Renal/Intrarenal
Post-renal
Which is the most common type of cause of AKI?
Pre-renal
What is pre-renal caused AKI due to?
Inadequate supply to kidneys reducing filtration of blood
What can cause the inadequate blood supply resulting in pre-renal AKI?
- Dehydration
- Hypotension (shock/volume depletion)
- Heart failure (reduced effective circulating volume)
- Renal artery stenosis
- Renal hyperfusion
- Pharmacological (NSAIDs, ACEi)
What is renal AKI?
Where intrinsic disease in kidney is leading to reduced filtration of blood
Possible causes of Renal AKI?
- Ischaemic injury
- Nephrotoxic injury
- Immune-mediated injury
- Vasculitis/vascular disease
- Interstitial nephritis
- Glomerulonephritis
- Acute tubular necrosis
What is the cause of post-renal AKI?
Obstruction to outflow of urine from kidney, causing back-pressure into kidney and reduced kidney function
What is the cause of post-renal AKI called?
Obstructive uropathy
What can renal obstruction be caused by?
- Kidney stones
- Blood clots
- AAA
- Masses eg cancer (usually retroperitoneal)
- Ureter or ureteral strictures
- Enlarged prostate/prostate cancer
- Bladder issues (malignancy, blood clot)
- strictures
Signs/symptoms of AKI?
Non-specific:
- Anorexia, wt loss, fatigue, lethargy
- N/V
- Itch
- Fluid overload
Signs:
- Uraemia including itch
- Pericarditis
- Oliguria
What may pre-renal AKI presnet with?
- Hypovolaemia
- Hypotension
What does hypotension/hypovolaemia present as?
- Thirst
- Dizziness
- Weakness
- Diarrhoea
Investigations for AKI?
- Urinalysis: protein, blood, glucose, nitrates
- U&Es
- FBC and coags
- Immunology: ANA, ANCAM, GBM
- Protein electrophoresis
How many stages in KDIGO staging and what is it?
3 stages
Kidney disease Improving Global Outcomes criteria
Stage 1 KDIGO?
Serum Creatinine: -Increase >26 micromol/L within 48 hours OR -1.5 fold increase in serum creatinine OR - -GFR decrease
or
Urine output criteria:
- <0.5ml’Kg/h for 6 hours
Stage 2 KDIGO?
Serum creatinine criteria:
- 2 fold increase in serum creatinine
- GFR decrease >50%
OR
Urine output criteria:
-<0.5ml/Kg/h for >12 hours
Stage 3 KDIGO?
Serum creatinine criteria: - 3 fold increase in serum creatinine OR -Increase >354 micromol/L OR -GFR decrease >75% OR started on renal replacement therapy
OR
Urine output criteria:
- <0.3mL/Kg/hr for >24 hours of 12 hours for anuria
Prevention of CKD?
- Avoiding nephrotoxic meds where possible
- Ensuring adequate fluid input in unwell patients