title: Near-infrared spectroscopy in the routine diagnostic work-up of patients with leg ischaemia.
abstract: OBJECTIVE
  To examine the reproducibility and clinical applicability of near-infrared spectroscopy (NIRS) in patients with leg ischaemia.
  
  
  METHODS
  Prospective comparative diagnostic study.
  
  
  METHODS
  Routinely measured peripheral blood pressure and microcirculatory parameters were compared with tissue oxygen saturation (TsO(2)) measurements using a new NIRS device on the calf muscle and the foot. Healthy subjects (n=20) and patients in different stages of leg ischaemia (n=45) were investigated at rest and after provocation: a treadmill test, arterial occlusion and a change in posture. Healthy volunteers were used as an age-matched reference population.
  
  
  RESULTS
  Reproducibility of the NIRS was excellent (intraclass correlation coefficient at rest was 0.91 (95% confidence interval: 80-99). Resting TsO(2) (65%) in healthy controls did not differ significantly from that in patients (Fontaine 2: 66%; F3/4: 68%). After exercise, a significant reduction in TsO(2) was observed only in patients: Fontaine 1: 60%; Fontaine 2: 21%, Fontaine 3/4: 29%. The ankle/brachial index after exercise showed a good correlation (R=0.73) with TsO(2) at the end of the treadmill test. No correlation between NIRS and other micro- or macrocirculatory parameters was found.
  
  
  CONCLUSIONS
  NIRS is a very reproducible tool to assess tissue oxygen saturation, but is not useful for the routine work-up of patients with leg ischaemia.
authors.affiliation: Department of Surgery, Academic Medical Center, 1100 DE Amsterdam, The Netherlands. d.ubbink@amc.uva.nl
authors.forename: D T
authors.initials: DT
authors.lastname: Ubbink
authors.forename: B
authors.initials: B
authors.lastname: Koopman
mesh_terms: D000328:Adult; D000368:Aged; D001794:Blood Pressure; D016022:Case-Control Studies; D003955:Diagnostic Tests, Routine; D005080:Exercise Test; D005260:Female; D006801:Humans; D007511:Ischemia / Q000175:diagnosis*; D007866:Leg / Q000098:blood supply*; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D010100:Oxygen / Q000378:metabolism; D011187:Posture; D011446:Prospective Studies; D015203:Reproducibility of Results; D012146:Rest; D019265:Spectroscopy, Near-Infrared
chemical_list: D010100:Oxygen