Effects of Low Chloride versus High Chloride Infusion on Glomerular Filtration Rate and Renal Plasma Flow in Healthy Volunteers—A Randomized, Controlled, Crossover Study

Abstract

Background: Previous studies have shown that chloride liberal fluids may be associated with worse renal outcomes. Deterioration of kidney function during hyperchloremia/chloride overload is believed to be induced by disturbances in renal perfusion, but exact mechanisms of chloride nephrotoxicity are unclear. The purpose of this randomized, crossover study was to investigate the effect of chloride loading on renal plasma flow (RPF), filtration fraction (FF) and glomerular filtration rate (GFR) in order to elucidate potential nephrotoxic mechanisms of chloride infusion. Methods: Fifteen healthy males were investigated twice after treatment with 2L isotonic saline and plasma-lyte with a wash-out period of at least 10 days. Within 15 mins after completion of infusion, the kidney parameters (RPF, FF and GFR) were estimated by Technetium-99m diethylenetriamine penta-acetic acid (99-mTc-DTPA) renography. Results: 99-mTc-DTPA renography showed reduction in both mean GFR (114 ± 13 ml/min vs.119 ± 12 ml/min, p = 0.04) and RPF (977 ± 272 ml/min vs. 1066 ± 197 ml/min, p = 0.19) and increasing FF (12% ± 2% vs. 11% ± 2%, p = 0.19) after 0.9% saline comparing to Plasmalyte, but only GFR reduction was statistically significant. Reduction in GFR and RPF and increasing in FF after 0.9% saline was observed in 10 subjects while in 5 others the reverse trend was shown. There were no statistically significant differences between mean systolic and diastolic blood pressure (BP) before and after each infusion except baseline diastolic BP. Weight changes (Δ weight) were similar after each infusion. Conclusions: We have demonstrated that high chloride infusion can affect kidney function in healthy subjects and seems to lead to impairment in both RPF and GFR.