title: Measurement of indocyanine green plasma disappearance rate by two different dosages.
abstract: OBJECTIVE
  While using a transcutaneous system for assessment of liver function by indocyanine green plasma disappearance rate (ICG-PDR) in critically ill patients, we compared the agreement between ICG-PDR obtained by the recommended standard ICG dosage (0.5 mg/kg) and a reduced dosage (0.25 mg/kg).
  
  
  METHODS
  Clinical study.
  
  
  METHODS
  Intensive care unit of a university hospital.
  
  
  METHODS
  Critically ill patients ( n=16, 5 female, 11 male) who underwent liver function monitoring by ICG-PDR for clinical indication.
  
  
  RESULTS
  We analyzed 31 pairs of ICG-PDR measurements by applying the recommended dosage (0.5 mg/kg, ICG-PDR(0.5)) and a reduced dosage (0.25 mg/kg, ICG-PDR(0.25)). For each comparative measurement either first 0.5 mg/kg or 0.25 mg/kg of ICG was injected in a random fashion and followed by the corresponding dosage 60 min later. All patients were sedated and mechanically ventilated via a tracheal tube. Each patient was monitored by an ICG finger clip which was connected to a liver function monitoring system (LiMon, Pulsion Medical Systems, Germany). ICG-PDR(0.25) was 2.7-25.0 %/min and ICG-PDR(0.5) 4.5-24.5 %/min, respectively. Linear regression analysis revealed ICG-PDR(0.25)=1.13.ICG-PDR(0.5)-0.66 %/min (r=0.95, p<0.0001) with a mean bias 1.0 %/min (standard deviation 2.5 %/min). The 15 min residual rates were also highly correlated ( r=0.92, p<0.0001) with a mean bias of 0.3%.
  
  
  CONCLUSIONS
  A reduced dosage of ICG (0.25 mg/kg) is sufficiently accurate for transcutaneous measurement of ICG-PDR in critically ill patients.
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, Friedrich-Schiller-University of Jena, Bachstrasse 18, 07740 Jena, Germany. Samir.Sakka@med.uni-jena.de
authors.forename: Samir G
authors.initials: SG
authors.lastname: Sakka
authors.forename: Heiko
authors.initials: H
authors.lastname: Koeck
authors.forename: Andreas
authors.initials: A
authors.lastname: Meier-Hellmann
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007208:Indocyanine Green / Q000378:metabolism; D016014:Linear Models; D008111:Liver Function Tests / Q000379:methods*; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D015203:Reproducibility of Results
chemical_list: D007208:Indocyanine Green