Acute Kidney Injury 2 Flashcards
What is the gold standard for GFR estimation?
Inulin clearance.
Why is inulin clearance not used routinely?
It is expensive and impractical for regular clinical use.
What is the traditional formula for estimating GFR in children?
Schwartz formula.
What are the age-dependent k values in the Schwartz formula?
Premature infant: 0.33, Term infant (up to 1 year): 0.45, Child/adolescent girl: 0.55, Adolescent boy: 0.7.
What is the adapted formula for enzymatic creatinine measurement?
CKiD Schwartz formula.
For what GFR range is the CKiD Schwartz formula accurate?
15–75 mL/min/1.73 m².
What is the reference GFR value for a premature infant?
<10 mL/min/1.73 m².
What is the GFR reference for term infants?
10–40 mL/min/1.73 m².
What is the GFR value for a 2-year-old child?
110–120 mL/min/1.73 m².
What factors affect the accuracy of serum creatinine as a GFR marker?
Non-steady kidney function, diet, hydration, medications, and hyperbilirubinemia.
What percentage of creatinine is secreted by the renal tubules?
10–40%.
What are the advantages of cystatin C over serum creatinine?
Independent of muscle mass, age, gender, and race; effective in early AKI detection.
What is a clinical use of cystatin C in AKI?
It predicts AKI 2 days before serum creatinine rise.
What are the limitations of cystatin C?
Lack of standardization in measurement.
Why is serum creatinine a limited marker for AKI?
Its rise is delayed and significant renal damage has occurred by the time of diagnosis.
What is the earliest biomarker for AKI?
Neutrophil Gelatinase-Associated Lipocalin (NGAL).
When does NGAL become detectable?
1–3 days before AKI diagnosis.
What does KIM-1 detect?
Acute tubular necrosis (ATN).
How long does KIM-1 remain elevated after AKI?
6–12 hours initially, stays high for 48 hours.
What injury does Interleukin-18 (IL-18) indicate?
Proximal tubular injury.
When does L-FABP appear in AKI?
Within 4 hours post-cardiopulmonary bypass (CPB) in children.
What does N-Acetyl-β-Glucosaminidase (NAG) indicate?
Tubular cell injury, such as nephrotoxicity or ischemia.
What is the benefit of combining biomarkers for AKI detection?
Increased sensitivity and specificity in early detection.
Which biomarkers are detectable early in AKI?
NGAL and L-FABP (2–4 hours).
What is the importance of sequential biomarker panels?
They enhance diagnostic accuracy, especially in critical care settings.
