Furosemide and Creatinine Tubular Stress Test in Order to Measure Proximal Tubule Residual Function: is It Better Than GFR?

Detailed Summary

This is a two phase study. The first part will take place at the National Institute of Cardiology in Mexico, the second phase will be made in collaboration with the University of California San Diego and University of Minnesota. This is a non blind experimental study, 72 patients with different stages of CKD from the outpatient unit of the institute will be included. Each patient will receive a furosemide stress test of 1 mg/kg in non diuretic users and 1.5 mg/kg in diuretic users, in addition of 5 grams of creatinine oral intake, as well as Iohexol 5ml IV to measure GFR. After the intervention, blood and urine samples will be drawn at baseline, 60 minutes, 180 minutes, and 240 min. Urine output will be maintained during the study by the intravenous administration of Hartman's solution 1 -2 ml/kg body weight every hour, in addition to the volume of urine output in the preceding hour plus oral water ingestion as tolerated. Blood and urine will be analized to measure creatinine (blood and urine), then samples will be processed for measurement of furosemide (HPLC-Uv vis), indoxyl sulphate, p-cresol, hippurate, and iohexol (mass spectometry). The aim of this stiudy is to asses the differences between GFR and proximal tubule function.

Study Details

Timeline

Interventions