title: Optimal back-extrapolation method for estimating plasma volume in humans using the indocyanine green dilution method.
abstract: BACKGROUND
  The indocyanine green dilution method is one of the methods available to estimate plasma volume, although some researchers have questioned the accuracy of this method.
  
  
  METHODS
  We developed a new, physiologically based mathematical model of indocyanine green kinetics that more accurately represents indocyanine green kinetics during the first few minutes postinjection than what is assumed when using the traditional mono-exponential back-extrapolation method. The mathematical model is used to develop an optimal back-extrapolation method for estimating plasma volume based on simulated indocyanine green kinetics obtained from the physiological model.
  
  
  RESULTS
  Results from a clinical study using the indocyanine green dilution method in 36 subjects with type 2 diabetes indicate that the estimated plasma volumes are considerably lower when using the traditional back-extrapolation method than when using the proposed back-extrapolation method (mean (standard deviation) plasma volume = 26.8 (5.4) mL/kg for the traditional method vs 35.1 (7.0) mL/kg for the proposed method). The results obtained using the proposed method are more consistent with previously reported plasma volume values.
  
  
  CONCLUSIONS
  Based on the more physiological representation of indocyanine green kinetics and greater consistency with previously reported plasma volume values, the new back-extrapolation method is proposed for use when estimating plasma volume using the indocyanine green dilution method.
authors: Cardiovascular and Metabolism, Janssen Research & Development, LLC, 3210 Merryfield Row, San Diego, CA 92121, USA. dpolido1@its.jnj.com.
authors: David
authors: D
authors: Polidori
authors: Clarence
authors: C
authors: Rowley
mesh_terms: D000328:Adult; D000368:Aged; D003198:Computer Simulation; D003710:Demography; D004395:Dye Dilution Technique; D005260:Female; D006801:Humans; D007208:Indocyanine Green; D008099:Liver / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D010953:Plasma Volume / Q000502:physiology*
chemical_list: D007208:Indocyanine Green