2. Anatomy and Physiology

Renal And Fluid Balance — Quiz

Test your understanding of renal and fluid balance with 5 practice questions.

Practice Questions

Question 1

A nurse administers 1 L of 0.45% NaCl intravenously. Assuming standard fluid distribution (ECF = 1/3 TBW, ICF = 2/3 TBW), approximately how much of the infused volume enters the ICF?

Question 2

Calculate the fractional excretion of sodium (FeNa) given urine sodium 20 mEq/L, plasma sodium 140 mEq/L, urine creatinine 50 mg/dL, and plasma creatinine 1 mg/dL using $FeNa=\frac{U_{Na}\times P_{Cr}}{P_{Na}\times U_{Cr}}\times100\\%$.

Question 3

Using the Henderson–Hasselbalch equation $pH=pKa+\log_{10}\frac{[HCO_3^-]}{0.03P_{CO_2}}$, calculate the pH for $[HCO_3^-]=18\,$mEq/L and $P_{CO_2}=50\,$mmHg (assume $pKa=6.1$).

Question 4

For a patient with metabolic acidosis and serum bicarbonate of 12 mEq/L, what is the expected $PaCO_2$ (mmHg) using Winter’s formula $PaCO_2=1.5[HCO_3^-]+8\pm2$?

Question 5

Which statement correctly contrasts the effects of loop diuretics and thiazide diuretics on renal calcium handling?