Combined oximetry-cutaneous capnography in patients assessed for long-term oxygen therapy.
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.
Török
Salome Schafroth
SS
Department of Pulmonary Medicine, University Hospital, Basel, Switzerland.
Leuppi
Jörg D
JD
Department of Pulmonary Medicine, University Hospital, Basel, Switzerland.
Baty
Florent
F
Department of Pulmonary Medicine, University Hospital, Basel, Switzerland.
Tamm
Michael
M
Department of Pulmonary Medicine, University Hospital, Basel, Switzerland.
Chhajed
Prashant N
PN
Department of Pulmonary Medicine, University Hospital, Basel, Switzerland. Electronic address: pchhajed@uhbs.ch.
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
D010100:Oxygen