Renal Flashcards
AKI
major side effect of other medical procedures, diverse spectrum of molecular, biochemical and structural processes that characterize the AKI syndrome
The RIFLE Classification of AKI
Risk for renal dysfunction –Injury to kidney –Failure of kidney function –Loss of kidney function –End stage renal disease
These classes represent degrees of injury
R = Risk for renal dysfunction I = Injury to the kidney F = Failure of kidney function
These classes represent outcome measures
L = Loss of kidney function, E = End stage renal disease (ESRD)
R = Risk for renal dysfunction
Increase in serum creatinine ≥ 1.5× baseline, Decrease in GFR ≥ 25%, UO < 0.5 mL/kg/h for 6 h
I = Injury to the kidney
Increase in serum creatinine ≥ 2.0× baseline, Decrease in GFR ≥ 50% < 0.5 mL/kg/h for 12 h
F = Failure of kidney function
Increase in serum creatinine ≥ 3.0× baseline OR serum creatinine ≥ 4.0mg/dL in the setting of an acute rise ≥ 0.5 mg/dL, Decrease in GFR ≥ 75%, < 0.3 mL/kg/h for 24 h or anuria for 12 h
L = Loss of kidney function
Persistent failure > 4 weeks
E = End stage renal disease (ESRD)
Persistent failure > 3 months
AKIN criteria
• To further refine the definition of AKI • Proposed a modified version of the RIFLE classification, known as the AKIN• An abrupt (within 48 h) reduction in kidney function as measured by an absolute increase in serum creatinine ≥ 0.3 mg/dL, • A percentage increase in serum creatinine ≥ 50%, • Or documented oliguria (
AKIN with RIFLE
AKIN replaces the three levels of severity R, I and F with stages 1, 2 and 3.
Besides Establishing the Early Diagnosis Biomarkers are needed to determine:
- Location of injury
- Duration of AKI
- AKI subtypes
- AKI etiologies
- Differentiate from other forms of acute kidney disease
- Risk stratification and prognostication
- Defining course of AKI
- Monitoring interventions
Biomarkers also used for
Also- desperately needed for use as surrogate endpoints in clinical trials evaluating potential therapeutics for AKI
validation
This linking of the surrogate endpoint to the clinical endpoint is referred to as validation and is an essential step in the biomarker discovery process
the most important AKI biomarkers remain
those that are clinically applicable and can lead to early diagnosis and treatment of AKI
prevalence of CKD in the general population
10-13% A complex disease that often affects multiple organ systems and often coexists with numerous associated conditions, such as cardiovascular disease, diabetes mellitus, lupus, & chronic inflammation
The ‘gold standard’ measurement for CKD
is the ‘true’ glomerular filtration rate (GFR) as tracked by 24-h urine isotope clearance, Method is quite expensive and not always practical in the clinical
setting
A commonly used clinical surrogate for nuclear GFR
serum creatinine clearance, the accuracy of serum creatinine is greatly affected by a number of patient dependent and -independent variables, Serum creatinine may fall to one-third of its normal level in advanced kidney disease, unrelated to its renal clearance, Serial 24-h creatinine measurements fail to determine risk progression in approximately 20% of CKD patients
CKD Definition
The presence of kidney damage or a glomerular filtration rate less than 60 mL/min/1.73 for 3 months or greater, regardless of cause However, significant increases in cardiovascular disease risk occur at
more subtle loss of kidney function (75) so it needs to be caught earlier
AKI definition
abrupt reduction in GFR –> Acumulation of nitrogenous wastes, disturbed f+e balance, and abnormal volume status. Can be polyuric, nonliguric, anuric - can do AKIN or RIFLE. Increase in sCr by 50% in 7 days, or increase by 0.3 in 2 days or oliguria
AKD
Classifies patients who may need intervention to restore kidney function or reverse kidney damage. GFR < 60 for < 3 months
Proteinuria
Shown to directly represent kidney damage and higher levels of proteinuria correlate well with a more rapid progression of kidney disease, The earliest known marker of kidney damage in glomerular diseases, diabetes and hypertension, and is the most common marker of kidney damage in the adult population Early diagnosis would entail routinely screening asymptomatic patients
However, proteinuria has limitations
May occur long after the renal injury has occurred
• Not always present in many types of renal disease
Stages of chronic kidney disease
stages 1-5.