Abstract
Purpose
To compare the capnography monitoring performance of the new OxyArm™ (OA) with the Capnoxygen mask (CM), a conventional oxygen mask with a carbon dioxide sampling port.
Methods
Eleven healthy volunteer adult subjects underwent capnographic monitoring (in a non-randomized, un-blinded crossover study) at baseline and while receiving oxygen at seven different flow rates (0.5, 1.0, 2.0, 4.0, 6.0, 8.0, and 10 L· min−1), applied first with the CM and then with the OA.
Results
Both the OA and CM produced acceptable capnographs with consistent waveforms. The measured end-tidal (ET) CO2 was equivalent for the two devices at all seven oxygen flow rates. On average, the ETCO2 measured with the OA was about 2 mmHg greater than that of the CM. Regression analysis showed an inverse relationship between oxygen therapy flow rate and measured ETCO2 whereby the measured value of CO2 decreased as the oxygen flow rate was increased (P < 0.001). Both the CM and OA produced consistent measurements of ETCO2 as illustrated by their reliability coefficients, 0.95 and 0.86 respectively. The biggest source of variation in measured CO2 for both devices was intersubject differences, followed by variable oxygen flow rates.
Conclusions
This study suggests that the OA and CM can prove useful for respiratory monitoring and oxygen delivery in spontaneously breathing volunteers, and the OA could potentially be used as an alternative to the conventional methods of oxygen delivery and CO2 sampling in patients.
Résumé
Objectif
Comparer les capacités de surveillance capnographique du nouveau OxyArm (OA) à celles du masque Capnoxygen (MC), un masque à oxygène traditionnel comportant un port de prélèvement du gaz carbonique.
Méthode
Onze volontaires adultes en bonne santé ont été placés sous surveillance capnographique pendant une étude croisée, sans aveugle et non randomisée. Des mesures de base ont été prises, puis répétées pendant l’oxygénothérapie selon sept différents débits (0,5, 1,0, 2,0, 4,0, 6,0, 8,0 et 10 L· min−1) administrée d’abord avec le MC, puis avec l’OA.
Résultats
Autant l’OA que le MC ont produit des capnographes acceptables et de forme cohérente. La valeur du CO2 télé-expiratoire (ET “end-tidal”) a été la même avec les deux appareils, pour les sept débits d’oxygène différents. En moyenne, les mesures du ETCO2 de l’OA ont été plus élevées que celles du MC, de 2 mmHg environ. L’analyse de régression a montré une relation inverse entre le débit de l’oxygénothérapie et le ETCO2 mesuré. La valeur du CO2 a diminué à mesure que le débit d’oxygène a augmenté (P < 0,001). Le MC et l’OA ont tous deux produit des mesures cohérentes de ETCO2 comme l’indiquent leurs coefficients de fiabilité, 0,95 et 0,86 respectivement. La plus importante source de variation des mesures de CO2 a été, pour les deux appareils, les différences entre les sujets de l’étude, puis ies différents débits d’oxygène.
Conclusion
Létude montre que l’OA et le MC peuvent servir à la surveillance respiratoire et à l’oxygénothérapie chez des volontaires respirant spontanément. L’OA pourrait sans doute remplacer l’oxygénothérapie et le prélèvement de CO2 traditionnels.
Article PDF
Similar content being viewed by others
References
Canadian Anesthesiologists’ Society. Guidelines to the practice of anesthesia. Revised edition 2000. Can J Anesth 1999; (Suppl) 46: 9.
Moon R, Camporesi E. Respiratory monitoring. In: Miller RD (Ed.). Anesthesiology, fourth edition, volume 1. New York: Churchill Livingstone Inc.; 1994: 1253–91.
Egleston CV, Aslam HB, Lambert MA. Capnography for monitoring non-intubated spontaneously breathing patients in an emergency room setting. J Accid Emerg Med 1997; 14: 222–4.
Loughnan TE, Monagle J, Copland JM, Ranjan P, Chen MF. A comparison of carbon dioxide monitoring and oxygenation between facemask and divided nasal cannula. Anaesth Intensive Care 2000; 28: 151–4.
Cheng KI, Tang CS, Tsai EM, Wu CH, Lee JN. Correlation of arterial and end-tidal carbon dioxide in spontaneously breathing patients during ambulatory gynecologic laparoscopy. J Formos Med Assoc 1999; 98: 814–9.
Ling E, McDonald L, Dinesen TR, DuVall D. The OxyArm™-a new minimal contact oxygen delivery system for mouth or nose breathing. Can J Anesth 2002; 49: 297–301.
Bland JM, Altman DG. Statistical methods for assessing agreement between two methods of clinical measurement. Lancet 1986; I: 307–10.
Streiner DL, Norman GR. Health Measurement Scales. A Practical Guide to Their Development and Use. Second Edition. New York: Oxford University Press; 1995.
Hills M, Armitage P. The two-period cross-over clinical trial. Br J Pharmac 1979; 8: 7–20.
Author information
Authors and Affiliations
Corresponding author
Additional information
The Capnographic OxyArm™ development was carried out at Southmedic Inc. and the study was carried out at Dr. S. McDonald’s office, 50 Alliance Blvd, Barrie, Ontario, Canada. Supported by a grant from Southmedic, Inc. of Barrie, Ontario, Canada.
Rights and permissions
About this article
Cite this article
Paul, J., Ling, E., Hajgato, J. et al. Both the OxyArm™ and Capnoxygen mask provide clinically useful capnographic monitoring capability in volunteers. Can J Anaesth 50, 137–142 (2003). https://doi.org/10.1007/BF03017845
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF03017845