A portable fiberoptic ratiometric fluorescence analyzer provides rapid point-of-care determination of glomerular filtration rate in large animals

Kidney Int. 2012 Jan;81(1):112-7. doi: 10.1038/ki.2011.294. Epub 2011 Aug 31.


Measurement of the glomerular filtration rate (GFR) is the gold standard for precise assessment of kidney function. A rapid, point-of-care determination of the GFR may provide advantages in the clinical setting over currently available assays. Here we demonstrate a proof of principle for such an approach in a pig and dogs, two species that approximate the vascular access and GFR results expected in humans. In both animal models, a sub-millimeter optical fiber that delivered excitation light and collected fluorescent emissions was inserted into a peripheral vein (dog) or central venous access (pig) by means of commercial intravenous catheters. A mixture of fluorescent chimeras of a small freely filterable reporter and large non-filterable plasma volume marker were infused as a bolus, excited by light-emitting diodes, and the in vivo signals detected and quantified by photomultiplier tubes in both species in less than 60 min. Concurrent standardized 6-h iohexol plasma kidney clearances validated the accuracy of our results for both physiologic and a chronic kidney disease setting. Thus, our ratiometric technique allows for both measurement of plasma vascular volume and highly accurate real-time GFR determinations, enabling clinical decision making in real time.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Dogs
  • Equipment Design
  • Fluorescent Dyes
  • Glomerular Filtration Rate*
  • Iohexol
  • Kidney Function Tests / instrumentation
  • Kidney Function Tests / veterinary*
  • Optical Fibers*
  • Point-of-Care Systems
  • Radiometry / instrumentation
  • Radiometry / veterinary
  • Swine


  • Fluorescent Dyes
  • Iohexol