A patient is infused with paraaminohippuric acid (PAH) to measure renal blood flow (RBF). She has a urine flow rate of $1 \mathrm{~mL} / \mathrm{min}$, a plasma [PAH] of $1 \mathrm{mg} / \mathrm{mL}$, a urine $[\mathrm{PAH}]$ of $600 \mathrm{mg} / \mathrm{mL}$, and a hematocrit of $45 \%$. What is her "effective" RBF?

Question

Quizplus · Accepted Answer

[II B 2, 3]. Effective renal plasma flow (RPF) is calculated from the clearance of para-aminohippuric acid (PAH) $\left[\mathrm{C}_{\mathrm{PAH}}=\mathrm{U}_{\mathrm{PAH}} \times \mathrm{V} / \mathrm{P}_{\mathrm{PAH}}=600 \mathrm{~mL} / \mathrm{min}\right]$. Renal blood flow $(\mathrm{RBF})=\mathrm{RPF} / 1-$ hematocrit $=1091 \mathrm{~mL} / \mathrm{min}$.

A Patient Is Infused with Paraaminohippuric Acid (PAH) to Measure 1 mL/min1 \mathrm{~mL} / \mathrm{min}1 mL/min

A Patient Is Infused with Paraaminohippuric Acid (PAH) to Measure $1 \mathrm{~mL} / \mathrm{min}$