Sandbox/equations
< Sandbox
Equations
Nephrology
- Anion gap = ([Na+] + [K+]) − ([Cl−] + [HCO3−])
we can simplify it to: Na-(Cl+HCO3) (Typically= 12±2mEq)
- Delta-delta(ΔΔ) = Δanion gap(calculated anion gap-expected)/ΔHCO3(24-measured HCO3)
- Urine anion gap = Urine anion gap is calculated by subtracting the urine concentration of chloride (anions) from the concentrations of sodium plus potassium (cations)= Na+ + K+ − Cl−
- Calculated osmoles = 2[Na+] + [Glucose]/18 + [ BUN ]/2.8 ,where [Glucose] and [BUN] are measured in mg/dL.
- Calculated osmolarity= 2 Na + Glucose + Urea (all in mmol/L)
- Osmolal gap= measured osmoles - calculated osmoles
- Estimated creatinine clearance =
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- Glomerular filtration rate (GFR) = Urine concentration×Urine flow/Plasma concentration
- Fractional Excretion of sodium =
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- Corrected sodium in hyperglycemia = measured Na + 2.4[(measured glucose-100)/100]
- Total body water = 0.60 × IBW(ideal body weight) (× 0.85 if female and × 0.85 if elderly)
- Free water deficit = 0.6 x weight (kg) x [(Current Na/140) - 1]
- Trans-tubular potassium gradient (TTKG) =
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