A 68-year-old man with stage 3b chronic kidney disease (eGFR 34 mL/min/1.73m²) presents for research study participation. Vital signs: BP 142/88 mmHg, HR 76/min, RR 14/min, Temp 37°C. Recent labs show serum creatinine 1.8 mg/dL and BUN 28 mg/dL. Researchers administer para-aminohippuric acid at low plasma concentration to measure renal clearance. The PAH is nearly completely removed during single-pass renal circulation. Which parameter does PAH clearance best approximate under these conditions?
- A)Renal plasma flowGABARITO
- B)Renal blood flow
- C)Free water clearance
- D)Glomerular filtration rate
- E)Filtration fraction
Explicação
At low plasma concentrations, PAH is both filtered and avidly secreted by the proximal tubule, so nearly all PAH delivered in the renal plasma is excreted. Therefore its clearance approximates effective renal plasma flow. Ver explicação completa e trilha adaptativa →