title: Reliable assessment of liver function using LiMAx.
abstract: BACKGROUND
  (13)C-liver function breath tests can facilitate the assessment of hepatic function in-vivo and may help surgeons to identify candidates for safe liver surgery. However, their acceptance into clinical practice is dependent on evaluation of technical efficacy and repeatability. The aims of this study were to evaluate the within-subject repeatability of the LiMAx (maximum liver function capacity) test in healthy individuals and in surgical patients to determine liver function in the perioperative workup.
  
  
  METHODS
  The LiMAx test, which is based on intravenous injection of (13)C-methacetin at a dosage of 2 mg/kg body weight was performed in eighty-six healthy subjects to determine a reference range. Twenty-four subjects underwent repeat LiMAx testing the following day to assess within-subject repeatability. Twenty-one patients undergoing elective extra-abdominal surgery under general anesthesia (GA group) received pre- and post-operative examinations.
  
  
  RESULTS
  The normal range of LiMAx was found to be 430 ± 86 μg/kg/h and revealed a one-sided cut-off value of 315 μg/kg/h. The intraclass correlation coefficient of the repeat LiMAx tests was 0.85 (95% confidence interval 0.69-0.93) in the control group and 0.81 (95% confidence interval 0.60-0.92) in the group of patients with GA.
  
  
  CONCLUSIONS
  The LiMAx test shows excellent reproducibility in subjects with normal liver function. GA has no effect on test results.
authors.affiliation: Department of General, Visceral and Transplantation Surgery, Charité - Universitätsmedizin Berlin -Campus Virchow-Klinikum, Berlin, Germany.
authors.forename: Maximilian
authors.initials: M
authors.lastname: Jara
authors.affiliation: Department of General, Visceral and Transplantation Surgery, Charité - Universitätsmedizin Berlin -Campus Virchow-Klinikum, Berlin, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Bednarsch
authors.affiliation: Department of General, Visceral and Transplantation Surgery, Charité - Universitätsmedizin Berlin -Campus Virchow-Klinikum, Berlin, Germany.
authors.forename: Erika
authors.initials: E
authors.lastname: Valle
authors.affiliation: Department of General, Visceral and Transplantation Surgery, Charité - Universitätsmedizin Berlin -Campus Virchow-Klinikum, Berlin, Germany.
authors.forename: Johan Friso
authors.initials: JF
authors.lastname: Lock
authors.affiliation: Department of General, Visceral and Transplantation Surgery, Charité - Universitätsmedizin Berlin -Campus Virchow-Klinikum, Berlin, Germany.
authors.forename: Maciej
authors.initials: M
authors.lastname: Malinowski
authors.affiliation: Department of General, Visceral and Transplantation Surgery, Charité - Universitätsmedizin Berlin -Campus Virchow-Klinikum, Berlin, Germany.
authors.forename: Antje
authors.initials: A
authors.lastname: Schulz
authors.affiliation: Department of General, Visceral and Transplantation Surgery, Charité - Universitätsmedizin Berlin -Campus Virchow-Klinikum, Berlin, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Seehofer
authors.affiliation: Center for Musculoskeletal Surgery, Charité - Universitätsmedizin Berlin - Campus Virchow-Klinikum, Berlin, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Jung
authors.affiliation: Department of General, Visceral and Transplantation Surgery, Charité - Universitätsmedizin Berlin -Campus Virchow-Klinikum, Berlin, Germany. Electronic address: martin.stockmann@charite.de.
authors.forename: Martin
authors.initials: M
authors.lastname: Stockmann
mesh_terms: D000005:Abdomen / Q000601:surgery; D000081:Acetamides; D000328:Adult; D001944:Breath Tests / Q000379:methods; D002245:Carbon Dioxide / Q000378:metabolism; D002247:Carbon Isotopes; D017558:Elective Surgical Procedures; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008111:Liver Function Tests / Q000379:methods* / Q000592:standards*; D008297:Male; D008954:Models, Biological; D011300:Preoperative Care / Q000379:methods / Q000592:standards; D012016:Reference Values; D015203:Reproducibility of Results; D055815:Young Adult
chemical_list: D000081:Acetamides; D002247:Carbon Isotopes; C035495:methacetin; D002245:Carbon Dioxide
keywords: Intra-individual repeatability; Liver function; Liver function test; Surgery; Within-subject repeatability