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

Abstract

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.

• Authors: Exing Wang, Daniel J Meier, Ruben M Sandoval, Vanessa E Von Hendy-Willson, Barrak M Pressler, Robert M Bunch, Mouhamad Alloosh, Michael S Sturek, George J Schwartz, Bruce A Molitoris
• Journal: Kidney international (Kidney Int) Vol. 81 Issue 1 Pg. 112-7 (Jan 2012) ISSN: 1523-1755 [Electronic] United States
• PMID: 21881552 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Fluorescent Dyes
• Iohexol

Topics

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