Renal Flashcards
(185 cards)
What is an acute kidney injury?
-An abrupt loss of kidney function (within 48 hours) resulting in the retention of urea and other waste products = dysregulation of extracellular volume and electrolytes
What are the 3 criteria that defines AKI?
- Increase in serum creatinine of >26.4μmol/L above baseline
- Increase in serum creatinine of >50%
- Oliguira <0.5mL/kg/hr for >6hr
Who are high risk patients for AKI?
- CKD
- Diabetics
- Diffuse atherosclerotic disease
- CCF
- Multiple myeloma
- Elderly
How can the causes of AKI be classified?
- Pre-renal
- Renal
- Post renal
What are the pre renal causes of AKI?
- Volume depletion ie bleeding, D+V, burns
- Oedematous states ie Cardiac failure, cirrhosis, neprhotic syndrome
- Hyptension ie sepsis, shock
- CV
- Medications ie NSAID, COX-2, ACEi, ARB
What are the renal causes of AKI?
- Glomoerular disease ie glomerulonephritis, thrombosis
- Tubular injury ie prolonged ischaemia, nephrotoxins
- Acute interstitial nephritis ie drugs, infection, autoimmune disease
- Vascular disease ie Polyarteritis nodosa, vasculitis, renal artery stenosis
- Eclampsia
What are the post renal causes of AKI?
- Prostatic hypertrophy
- Calculus
- Blood clot
- Urethral stricture
- Tumour
- Pelvic malignancy
- Radiation fibrosis
What are the drugs known to cause AKI?
- NSAIDS
- gentamycin
- antifungals
- antivirals
- radio-iodine contrast
Who is most commonly affected by AKI?
-Elderly
What are risk factors for AKI?
- Age >65
- CKD with eGFR <60
- Past history of AKI
- CO-existing illness eg cardiac failure, liver disease, diabetes
- Neuroimpairment
- Hypovolaemia
- Symptoms of urological obstruction
- Sepsis
- Use of contrast
- Nephrotoxic Medications
- Perioperative period
How does AKI present?
-Decreasing urine volume and rise in serum creatinine
What are symptoms of an AKI?
- Decrease in urine output ie oliguria, anuria
- Nausea and vomiting
- Dehydration
- Confusion
What are signs of AKI?
- Hypertension
- Large painless bladder
- Fluid overload: ^JVP, pulmonary and peripheral oedema
- Postural hypotension and dehydration
- Pallor, rash, bruising
What investigations are required for an AKI?
- Urinalysis and urine microscopy
- Creatinine blood test along with other normals
- Blood film
- Immunology ie bence jones protein, ANCA, complement
- US (if obstruction suspected)
- Other radiology for systemic disease
- BIOPSY
How does CKD differ from AKI?
CKD:
- long duration of symptoms
- nocturia
- absence of illness
- anaemia
- hyperphosphatemia
- reduced renal size
How is AKI managed?
-Supportive treatment: >treat underlying cause >stop nephrotoxic drugs >monitor fluid and electrolytes >treat acute complications ie K+^, acidosis, pulmonary oedema, bleeding
What are the indications for dialysis (renal replacement therapy)
- Hyperkalaemia
- Pulmonary oedema refractory to medical management
- Severe metabolic acidaemia due to kidney failure
- Progressive renal failure (^creatinine)
- Uraemic complications ie pericarditis, altered mental state)
- Fluid overload
- Renal transplant
- CKD 4 or 5
What is the management bundle for AKI?
- Haemodynamic restoration (fluids and inotropes)
- Treatment of K+
- Input/output charting and frequent obs
- Urinalysis
- Stop nephrotoxins, drugs with haemodynamic effect, reduce doses of renally excreted drugs
What is CKD?
-Abnormal kidney function ie eGFR <60ml/min/1.73m^2 for longer than 3 months
or
-Kidney damage
What is are risk factors for CKD?
- Increasing age
- Diabetes
- CVD
- Proteinuria
- AKI
- Hypertension
- Smoking
- African, afro-carribean or asian ethnicity
- Chronic use of NSAIDs
- Untreated outflow obstruction
Classification of CKD?
- Stage 1: normal - eGFR >90 ml/minute/1.73 m2 with other evidence of chronic kidney damage (see below).
- Stage 2: mild impairment - eGFR 60-89 ml/minute/1.73 m2 with other evidence of chronic kidney damage.
- Stage 3a: moderate impairment - eGFR 45-59 ml/minute/1.73 m2.
- Stage 3b: moderate impairment - eGFR 30-44 ml/minute/1.73 m2.
- Stage 4: severe impairment - eGFR 15-29 ml/minute/1.73 m2.
- Stage 5: established renal failure (ERF) - eGFR less than 15 ml/minute/1.73 m2 or on dialysis.
What persistent findings may indicate CKD?
- Persistent microalbuminuria
- Persistent proteinuria
- Persistent haematuria
- Structural abnormalities ie PCKD
- Biopsy proven glomerulonephritis
How does CKD present?
- Usually incidentally on a routine blood or urine test
- Long/progressive disease
What are the symptoms of severe CKD?
Anorexia Nausea Vomiting Fatigue Pruritus Peripheral oedema Dyspnoea Insomnia Muscle cramps Pulmonary oedema Nocturia Headache Sexual dysfunction Very severe Hiccups Pericarditis Coma Seizures