title: Cerebral near infrared spectroscopy for the measurement of indocyanine green elimination in cirrhosis.
abstract: BACKGROUND
  Indocyanine green (ICG) clearance is a useful indicator of hepatic function but most measurement methods are invasive.
  
  
  OBJECTIVE
  To validate a less invasive technique using cerebral near infrared spectrophotometry (NIRS) to measure ICG elimination, and to compare it with the established methods for the determination of ICG clearance in a group of normal controls and patients with cirrhosis.
  
  
  METHODS
  NIRS was used to measure ICG elimination in 41 cirrhotic patients and nine healthy volunteers. The first 13 of the cirrhotic patients also had their ICG clearance measured by the conventional spectrophotometric technique.
  
  
  RESULTS
  NIRS ICG elimination rate (ICG-k) and spectrophotometry ICG-k values correlated strongly (r= 0. 828, P < 0.001, n=13). There was a significant reduction in the mean NIRS-k in cirrhotic patients and within Child-Pugh classes A, B, and C (P < 0.001).
  
  
  CONCLUSIONS
  Measurement of ICG elimination by the NIRS method is at least as reliable as the conventional spectrophotometric technique in normals and in patients with cirrhosis. This technique merits further development for use as a bedside, less invasive liver function test.
authors.affiliation: Liver Research Laboratories, Department of Medicine, Royal Infirmary of Edinburgh, Edinburgh, UK. G.Therapondos@ed.ac.uk
authors.forename: G
authors.initials: G
authors.lastname: Therapondos
authors.forename: J N
authors.initials: JN
authors.lastname: Plevris
authors.forename: A J
authors.initials: AJ
authors.lastname: Stanley
authors.forename: C J
authors.initials: CJ
authors.lastname: Peters
authors.forename: M
authors.initials: M
authors.lastname: Teig
authors.forename: P C
authors.initials: PC
authors.lastname: Hayes
mesh_terms: D004396:Coloring Agents / Q000032:analysis / Q000493:pharmacokinetics; D006801:Humans; D007208:Indocyanine Green / Q000032:analysis* / Q000493:pharmacokinetics; D008103:Liver Cirrhosis / Q000378:metabolism*; D008657:Metabolic Clearance Rate; D015203:Reproducibility of Results; D013055:Spectrophotometry, Infrared / Q000379:methods*
chemical_list: D004396:Coloring Agents; D007208:Indocyanine Green