A 45-year-old man with stage 3b chronic kidney disease (eGFR 34 mL/min/1.73m²) presents with BP 148/92 mmHg, HR 78/min, RR 16/min. Serum creatinine is 2.1 mg/dL with normal urinalysis. He takes lisinopril daily. A researcher administers an agent that selectively constricts the efferent arteriole. Renal plasma flow decreases modestly while glomerular capillary hydrostatic pressure initially rises. Which hemodynamic change occurs first?
- A)No change in filtration fraction
- B)Decrease in filtration fraction
- C)Increase in free water clearance only
- D)Complete loss of autoregulation with anuria
- E)Increase in filtration fractionGABARITO
Explicação
Mild efferent arteriolar constriction raises glomerular capillary hydrostatic pressure and tends to increase or preserve GFR while reducing renal plasma flow. Because filtration fraction equals GFR divided by RPF, the ratio rises under these conditions. Ver explicação completa e trilha adaptativa →