Renal Flashcards
(34 cards)
Define Acute Kidney Injury (AKI)
An abrupt decline in kidney function i.e. glomerular filtration rate (can be hours or days)
What are the 3 classifications of AKI?
- Pre-renal
- Post-renal
- Intrinsic
Define Pre-renal AKI
What is is caused by? (6)
- Blood flow to kidneys reduced, can cause ischaemic injury if not managed
- Reduced BP, hypovolaemia (blood loss), dehydration, GI bleed, sepsis and liver failure
Define Post-renal AKI
What can it be caused by?
- Obstruction to the outflow from kidneys
- Benign prostatic hypertrophy (BPH), prostate cancer, renal calculi, retroperitoneal fibrosis (scar tissue at back of abdomen)
Define Intrinsic AKI
- Damage to the function tissues of the kidney
- Acute interstitial nephritis (inflammation of renal interstitium), hypersensitivity reaction (often drug induced), myeloma (type of blood cancer), vasculitis (immunological renal disease
How can glomerular filtration rate measured?
- eGFR (ml/min/1.73m2)
- Creatinine clearance (ml/min)
What is the formulae used to calculate creatinine clearance
CrCl = F(140 - age) x weight / Serum Creatinine
F = 1.04 female F = 1.23 male
In what patients MUST creatinine clearance be calculated?
- Patients taking: Direct Oral Anticoagulants (DOACs) e.g. Dabigatran
Nephrotoxic drugs e.g. Cisplatin, Methotrexate, ACE
inhibs, Cyclosporine, NSAIDs, Tacrolimus
Drugs excreted renally e.g. antibiotics, beta-blockers,
diuretics, lithium, digoxin - > 75 years
- Extremes of muscle mass
- Narrow therapeutic index drugs e.g. Digoxin
What are the steps taken after a patient is found to have a low CrCl?
- Establish AKI or CKD
- Review all medications and assess adjustments e.g. always stop ACE inhibs in AKI, BUT not CKD as it is renal protective
- Check dosing based on eGFR
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Define Chronic Kidney Injury (CKD)
Abnormalities of kidney function or structure present, for > 3 months, with health implications
What is ACR?
- Albumin : Creatinine ratio
- Normally proteins are not filtered into tubules of nephron, they remain in blood due to size
- As CKD progresses, structure breaks down causing ‘leaks’ allowing protein to be filtered and into the urine where it can be detected
- Greater amount of albumin in urine = more severe CKD
What are the risk factors for CKD? (6)
- Hypertension (more strain on tubules)
- UTIs, especially recurrent ones
- Medication e.g. Lithium, NSAIDs
- CVD
- Age
- Malignancy
How is CKD testing prompted?
- Albumin, proteins or blood in urine
- Ultrasound or biopsy results
What are the clinical complications of CKD? (8)
- Acidosis
- Anaemia
- Dyslipidaemia
- Fluid overload
- Hyperkalaemia
- Hypertension
- Mineral & bone disorder
- Uraemia
What is acidosis?
How is it managed?
What are the SE of treatment?
- Result of blood becoming more acidic due to kidneys inability to excrete H+ and reabsorb HCO3-
- Long term sodium bicarbonate (1g TDS)
- Increase in Na = water retention (Na and water diffuse together)
What is renal anaemia?
What causes it?
How do you manage it?
- When quality or quantity of RBC are below normal
- Lack of circulating iron: by blood loss, dietary inadequacy, poor absorption of Fe due to uraemia or use of phosphate binders, impaired erythropoiesis due to lack of erythropoietin, long term use of immunosuppressants
- Pre-dialysis management: oral iron, 3 months MAX
- Dialysis patients: IV iron, given after dialysis
What is erythropoietin?
- A naturally occurring hormone produce by the kidneys
- Stimulates bone marrow to produce red blood cells (erythrocytes)
- CKD patients have little to no circulating EPO
How can you manage a lack of erythropoietin?
Erythropoietin stimulating agents (ESA)
- Eprex: recombinant human EPO, given SC once weekly
- Aransep: Given IV to dialysis patients, once weekly
What is dyslipidaemia?
How do you manage?
- Abnormal lipid metabolism in CKD
- Causes high rate of CVD in CKD
- Atorvastatin 20mg OD
How does fluid overload occur in CKD?
Due to kidneys inability to maintain Na and fluid balance
How would you manage fluid overload in CKD?
- Restrict Na diet (salt), and fluid intake
- Diuretic therapy: Loop diuretic e.g. furosemide in high dose
- If medication ineffective = dialysis
- AVOID meds with high Na e.g. effervescent medication
What can be the consequence of hyperkalaemia (high potassium)?
- Damaging to hear muscles and cause abnormal rhythms
How would you manage hyperkalaemia in CKD? (4)
Non-pharmacological: restrict dietary potassium
Pharmacological:
- Calcium resonium orally TDS
- IV Calcium gluconate
- Actrapid insulin (pushed K+ into cells, avoiding heart)
- Dialysis as last option
BEWARE drugs exacerbating hypokalaemia e.g. potassium sparing diuretics e.g. Spironolactone) Digoxin and NSAIDs
How would you manage hypertension in CKD?
- ACE inhibitor e.g. Ramipril
- Angiotensin Receptor Blockers (ARBs) e.g. _____sartan
RENOPROTECTIVE IN CKD
