Untitled Flashcard Set

BUN Assay

BUN = (A Unknown ÷ A Standard) × 30, used to determine BUN concentration.

Creatinine Assay

Creatinine = (ΔA Unknown ÷ ΔA Standard) × 5, used to determine creatinine concentration.

Urea Conversion

Urea = BUN × 2.14, used to convert BUN to Urea.

BUN Conversion

BUN = Urea ÷ 2.14, used to convert Urea to BUN.

BUN/Creatinine Ratio

BUN ÷ Creatinine, evaluates renal perfusion/function.

Anion Gap (with K)

Na + K − (Cl + HCO3), used for metabolic acidosis evaluation.

Anion Gap (without K)

Na − (Cl + HCO3), the most common AG calculation.

Calculated Osmolality

2(Na) + Glucose/20 + BUN/3, estimates serum osmolality.

Alternative Osmolality

1.86(Na) + Glucose/18 + BUN/2.8 + 9, a more precise estimate of osmolality.

Osmolal Gap

Measured − Calculated Osmolality, detects unmeasured osmoles.

Sodium (Na) Reference Range

135–145 mmol/L, normal range for sodium.

Potassium (K) Reference Range

3.5–5.0 mmol/L, normal range for potassium.

Chloride (Cl) Reference Range

96–106 mmol/L, normal range for chloride.

Bicarbonate (HCO3) Reference Range

22–29 mmol/L, normal range for bicarbonate.

Calcium (Ca) Reference Range

8.5–10.5 mg/dL, normal range for calcium.

Creatinine Female Reference Range

0.6–1.1 mg/dL, reflects GFR in females.

Creatinine Male Reference Range

0.7–1.3 mg/dL, reflects GFR in males.

Creatinine Clearance Female

95 ± 20 mL/min, indicates kidney filtration in females.

Creatinine Clearance Male

105 ± 20 mL/min, indicates kidney filtration in males.

Uric Acid Reference Range

2.6–7.2 mg/dL, related to purine metabolism.

Ammonia Reference Range

19–60 mg/dL, related to liver and nitrogen metabolism.