title: Combined oximetry-cutaneous capnography in patients assessed for long-term oxygen therapy.
abstract: OBJECTIVE
  To evaluate the feasibility of combined oximetry (pulse oximetric saturation [Spo(2)]) and cutaneous capnography (transcutaneous carbon dioxide tension [Ptcco(2)]) for oxygen titration in patients requiring long-term oxygen therapy.
  
  
  METHODS
  Twenty patients with obstructive or restrictive lung disease underwent oxygen titration using a combined cutaneous oximetry-capnography sensor. The goal of titration was to achieve an oxygen saturation of > 90% without a significant rise in carbon dioxide. Spo(2) and Ptcco(2) measurements at the end of titration were compared with blood gas levels using Bland-Altman analysis and linear regression analysis.
  
  
  RESULTS
  The mean (+/- SE of the estimate) Pao(2) while breathing room air was 53.2 +/- 8.1 mm Hg and increased to 75.9 +/- 13.3 mm Hg with oxygen supplementation (p < 0.0001). The mean Paco(2) was 45.9 +/- 8.7 mm Hg at baseline and 47.8 +/- 9.0 mm Hg after oxygen titration (p = 0.003). Bland-Altman analysis for comparison of Ptcco(2) and Paco(2) showed a bias of 0.86 mm Hg with a precision of 3.48 mm Hg. Bland-Altman analysis for the comparison of Spo(2) and arterial oxygen saturation showed a bias of 0.14% with a precision of 1.13%.
  
  
  CONCLUSIONS
  Combined oximetry and cutaneous capnography is feasible during oxygen titration in patients needing long-term oxygen therapy. This noninvasive approach has the potential to reduce the number of arterial blood gas samplings performed.
authors.affiliation: Department of Pulmonary Medicine, University Hospital, Basel, Switzerland.
authors.forename: Salome Schafroth
authors.initials: SS
authors.lastname: Török
authors.affiliation: Department of Pulmonary Medicine, University Hospital, Basel, Switzerland.
authors.forename: Jörg D
authors.initials: JD
authors.lastname: Leuppi
authors.affiliation: Department of Pulmonary Medicine, University Hospital, Basel, Switzerland.
authors.forename: Florent
authors.initials: F
authors.lastname: Baty
authors.affiliation: Department of Pulmonary Medicine, University Hospital, Basel, Switzerland.
authors.forename: Michael
authors.initials: M
authors.lastname: Tamm
authors.affiliation: Department of Pulmonary Medicine, University Hospital, Basel, Switzerland. Electronic address: pchhajed@uhbs.ch.
authors.forename: Prashant N
authors.initials: PN
authors.lastname: Chhajed
mesh_terms: D000368:Aged; D001784:Blood Gas Analysis; D001785:Blood Gas Monitoring, Transcutaneous / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D016014:Linear Models; D008171:Lung Diseases / Q000097:blood / Q000188:drug therapy*; D008297:Male; D010092:Oximetry / Q000379:methods*; D010100:Oxygen / Q000097:blood / Q000627:therapeutic use*; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood / Q000188:drug therapy*; D012129:Respiratory Function Tests
chemical_list: D010100:Oxygen