Renal equations (Pg. 552-554) COPY Flashcards
Renal clearance
= UxV/Px
GFR equation
= Uinulin × V/Pinulin = Cinulin
= Kf [(PGC – PBS) – (πGC – πBS)]
Normal GFR
≈ 100 mL/min.
eRPF equation
= UPAH × V/PPAH = CPAH
Renal blood flow equation
= RPF/(1 − Hct).
Filtration fraction equation
= GFR/RPF
Normal filtration fraction
= 20%.
Filtered load equation
= GFR × Px
Excretion rate
= V × Ux
Reabsorption rate
= filtered – excreted
Secretion rate
= excreted – filtered
FeNa equation
= Na excreted / Na filtered
= UNa × V / GFR (UCr × V/ PCr ) × PNa
= UNa × PCr / UCr × PNa
Henderson-Hasselbach equation
pH = 6.1 + log ([HCO3-]/0.03 PCO2)
Winters formula?
For what?
PCO2 = 1.5 [HCO3-] + 8 +/- 2
Predicted respiratory compensation for a simple metabolic acidosis
If measured PCO2 > predicted PCO2 —> concomitant respiratory acidosis
If measured PCO2 < predicted PCO2 —> concomitant respiratory alkalosis
Anion Gap
NL?
> NL?
= Na - (Cl + HCO3)
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