L2 AKI CKD Flashcards
what is AKI
Abrupt decline in renal function leading to an increase in serum concentrations of urea, creatinine & other substances (occurs over a period of days)
what r the major risk factor for AKI
PATIENT FACTORS: - old age (>75) - diabetes - atheroclerosis - chronic HT MEDICATIONS AND AGENTS RISK FACTOR - NSAIDS -ARB (angiotensin receptor blockers) - ACEIs (angiotensin converting enzyme inhibitors)
what r the current use biomarkers of AKI?
- increased serum creatinine
- increased urea nitrogen
how to diagnose AKI
Estimating Kidney Function in AKI
– Difficult because commonly used SCr based equation are not appropriate (assume stable SCr)
– Other equations such as Brater and Jeliffe may be more accurate than Cockcroft-Gault but less tested
what r the types of AKI and its pathophysiology
what causes different types of AKI
differential diagnosis by pathophysiology of AKI
clinical manifestation of AKI
AKI prevention
Identification of high-risk individuals
Optimisation of renal perfusion
– volume expansion and/or fluid therapy where appropriate
– vasopressors (e.g. adrenaline, dopamine) may be used once intravascular volume has been restored (patchy evidence however)
Avoidance of nephrotoxins wherever possible (and close monitoring when not)
– includes drugs, and combinations of drugs, e.g. triple whammy
Specific circumstances (examples)
– once daily dosing of aminoglycosides
– allopurinol and rasburicase to prevent tumour lysis syndrome
– Amphotericin whenever possible; limiting dose, rate of infusion.
Recognise that patients with pre-existing renal impairment are at higher risk of developing further renal insufficiency—treat and monitor accordingly
Temporarily withhold nephrotoxins (especially ACE-I, ARBs, NSAIDs) and diuretics (to prevent dehydration) when patients become unwell—either in the community or in hospital
Ensure that patients remain adequately hydrated, to maintain renal perfusion
AKI prevention (med perspective)
– Remember to monitor renal function after starting, or increasing the dose, of ACE-I or ARBs (check one to two weeks later)
– Where necessary, adjust drug doses in patients with renal impairment
– Monitor drug levels when using aminoglycoside (gentamicin) and/or glycopeptide (vancomycin) antibiotics - and adjust dose accordingly
– Hydrate the patient and consider using N-acetyl cysteine before procedures entailing radiological contrast media
how to manage pre-renal, intrinsic and post-renal AKI?
The most important step is to reverse the cause (which will depend on the type of AKI)
Pre-renal
– improve perfusion, remove offending medications
Intrinsic
– treatment of ATN primarily supportive
• no specific therapeutic intervention has been found to hasten recovery of kidney function
– use of diuretics to convert patients from oliguric to non-oliguric ATN not associated with improved outcomes
• may be helpful in volume management (need high doses e.g. >160mg frusemide), but cease if no response
– for AIN, avoid offending agent in future
Post-renal
– relieve obstruction
– All patients with significant AKI also require attentive management of volume, electrolyte (esp K+) and acid-base status, and nutrition
– Renal replacement therapy (RRT, dialysis) may be required in cases of severe AKI (hyperkalaemia, volume overload, severe acidosis, or overt uraemia)
what r the indication for renal replacement therapy
management of hyperkalemia
– Severe hyperkalaemia (K+ >6.5 mmol/L) is a medical emergency because of the risk of life threatening cardiac arrhythmias
principle of management AKI
drug dose consideration in AKI
– Optimising drug therapy for patients with AKI is challenging
– Factors that need considerations include; residual drug clearance, accumulation of fluids, and dialysis.
– For renally cleared drugs (>30% elimination unchanged in the urine), particularly for drugs with narrow therapeutic range, serum drug concentration and pharmacodynamic response is necessary.
what is CKD
– CKD is defined as kidney damage or GFR below 60ml/min/1.73m2 for 3 months or more irrespective of the cause.
– CKD is
– a long-term health condition (months/years),
preventable in many cases
– glomerular & tubular damage
– asymptomatic until much of the kidney function is lost
• compensatory and adaptive mechanisms maintain acceptable health until GFR is ~10 to 15 ml/min
evidence for CKD
– Evidence for CKD
– Proteinuria
– Reduced renal function
stages of CKD
CKD risk factors
CKD major cause