0
Communications to the Editor |

Detection of Hypoventilation FREE TO VIEW

Douglas C. Johnson, MD
Author and Funding Information

Boston, MA

Correspondence to: Douglas C. Johnson, MD, Spaulding Rehabilitation Hospital, 125 Nashua St, Boston, MA 02114; e-mail: djohnson5@partners.org



Chest. 2005;128(6):4049. doi:10.1378/chest.128.6.4049
Text Size: A A A
Published online

To the Editor:

The study by Fu et al (November 2004)1documents well that supplemental oxygen impairs the detection of hypoventilation by pulse oximetry, as discussed in the accompanying editorial by Demers.2 We regularly perform overnight oximetry on inpatients to screen for sleep apnea/hypopnea and find that the results are very insensitive if performed using supplemental oxygen. Therefore, we perform overnight oximetry either using room air or, if the baseline awake oxygen saturation level is < 90%, using only enough oxygen to bring the awake saturation to approximately 90%.

Fortunately, it is now possible to directly assess hypoventilation using continuous transcutaneous carbon dioxide tension monitoring.3 We now routinely monitor transcutaneous carbon dioxide pressure in patients who are at high risk for hypoventilation in our ventilator weaning program. We find monitoring to be very helpful during the initial tracheostomy using a mask or during overnight periods when the patient is not receiving ventilation, as well as during bronchoscopies. The advantages of monitoring cutaneous carbon dioxide tension over monitoring with end-tidal carbon dioxide tension, which we also use, include allowing continuous measurement, not requiring deep exhalation, and making accurate measurements in patients with high dead space ventilation.

The device (CO-OXSYS Monitor, SenTec AG; Therwil, Switzerland) has been used in Europe45 and is now available in the United States (Aspen Medical Products Inc; Irvine, CA). The monitor allows us to closely follow transcutaneous carbon dioxide pressure using a small probe that clips on the ear lobe. It usually takes about 5 min to equilibrate and then tracks carbon dioxide pressure closely, along with oxygen saturation.

Fu, ES, Downs, JB, Schweiger, JW, Miguel, RV, et al (2004) Supplemental oxygen impairs detection of hypoventilation by pulse oximetry.Chest126,1552-1558. [CrossRef] [PubMed]
 
Demers, B The oximeter: boon or bane?Chest2004;126,1399-1401. [CrossRef] [PubMed]
 
Chhajed, PN, Heuss, LT, Tamm, M Cutaneous carbon dioxide tension monitoring in adults.Curr Opin Anaesthesiol2004;17,521-525. [CrossRef] [PubMed]
 
Heuss, LT, Chhajed, PN, Schnieper, P, Hirt, T, et al Combined pulse oximetry/cutaneous carbon dioxid tension monitoring during colonoscopies: pilot study with a smart ear clip.Digestion2004;70,152-158. [CrossRef] [PubMed]
 
Chhajed, PN, Rajasekaran, R, Kaegi, B, et al Cutaneous carbon dioxide tension monitoring might enhance patient safety during flexible bronchoscopy and medical thoracoscopy [abstract]. Chest. 2004;;126(suppl) ,.:822S
 

Figures

Tables

References

Fu, ES, Downs, JB, Schweiger, JW, Miguel, RV, et al (2004) Supplemental oxygen impairs detection of hypoventilation by pulse oximetry.Chest126,1552-1558. [CrossRef] [PubMed]
 
Demers, B The oximeter: boon or bane?Chest2004;126,1399-1401. [CrossRef] [PubMed]
 
Chhajed, PN, Heuss, LT, Tamm, M Cutaneous carbon dioxide tension monitoring in adults.Curr Opin Anaesthesiol2004;17,521-525. [CrossRef] [PubMed]
 
Heuss, LT, Chhajed, PN, Schnieper, P, Hirt, T, et al Combined pulse oximetry/cutaneous carbon dioxid tension monitoring during colonoscopies: pilot study with a smart ear clip.Digestion2004;70,152-158. [CrossRef] [PubMed]
 
Chhajed, PN, Rajasekaran, R, Kaegi, B, et al Cutaneous carbon dioxide tension monitoring might enhance patient safety during flexible bronchoscopy and medical thoracoscopy [abstract]. Chest. 2004;;126(suppl) ,.:822S
 
NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging & repositioning the boxes below.

CHEST Journal Articles
PubMed Articles
  • CHEST Journal
    Print ISSN: 0012-3692
    Online ISSN: 1931-3543