A 58-year-old man with chronic kidney disease presents with fatigue and dyspnea. Vital signs: BP 156/92 mmHg, HR 88/min, RR 18/min, SpO2 98% on room air. Serum creatinine is 3.2 mg/dL; eGFR is 18 mL/min/1.73m². He denies hematuria. During a research study, inulin—a substance freely filtered at the glomerulus but neither reabsorbed, secreted, synthesized, nor metabolized by the kidney—is infused. The clearance of this substance equals which of the following?
- A)Filtration fraction
- B)Renal plasma flow
- C)Glomerular filtration rateGABARITO
- D)Urine flow rate
- E)Renal blood flow
Explicação
Inulin clearance is the gold standard measure of glomerular filtration rate because the filtered load exactly equals the excreted load. Since the substance undergoes no tubular handling, its clearance directly reflects filtration alone. Ver explicação completa e trilha adaptativa →