Combined oximetry-cutaneous capnography in patients assessed for long-term oxygen therapy

Chest. 2008 Jun;133(6):1421-1425. doi: 10.1378/chest.07-0960. Epub 2008 Mar 13.


Study aim: 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%.

Conclusion: 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.

MeSH terms

  • Aged
  • Blood Gas Analysis
  • Blood Gas Monitoring, Transcutaneous / methods*
  • Feasibility Studies
  • Female
  • Humans
  • Linear Models
  • Lung Diseases / blood
  • Lung Diseases / drug therapy*
  • Male
  • Oximetry / methods*
  • Oxygen / blood
  • Oxygen / therapeutic use*
  • Pulmonary Disease, Chronic Obstructive / blood
  • Pulmonary Disease, Chronic Obstructive / drug therapy*
  • Respiratory Function Tests


  • Oxygen