0
Clinical Investigations: SLEEP AND BREATHING |

Abbreviated Method for Assessing Upper Airway Function in Obstructive Sleep Apnea*

An Boudewyns, MD, PhD; N. Punjabi, MD; P. H. Van de Heyning, MD, PhD; W. A. De Backer, MD, PhD; C. P. O’Donnell, PhD; H. Schneider, MD, PhD; P. L. Smith, MD; A. R. Schwartz, MD
Author and Funding Information

*From the Departments of Otorhinolaryngology, Head and Neck Surgery (Drs. Boudewyns and Van de Heyning) and Pulmonary Medicine (Dr. De Backer), University Hospital, Antwerp, Belgium; and the Department of Pulmonary Medicine (Drs. Punjabi, O’Donnell, Schneider, Smith, and Schwartz), Johns Hopkins University, Baltimore, MD.

Correspondence to: An Boudewyns, MD, PhD, University Hospital Antwerp, Department of Otorhinolaryngology, Head and Neck Surgery, Wilrijkstraat 10, 2650 Edegem, Belgium; e-mail: an.boudewijns@uza.uia.ac.be



Chest. 2000;118(4):1031-1041. doi:10.1378/chest.118.4.1031
Text Size: A A A
Published online

Study objectives: Previous studies have shown that the level of flow through the upper airway in patients with obstructive sleep apnea (OSA) is determined by the critical closing pressure (Pcrit) and the upstream resistance (Rn). We developed a standardized protocol for delineating quasisteady-state pressure-flow relationships for the upper airway from which these variables could be derived. In addition, we investigated the effect of body position and sleep stage on these variables by determining Pcrit and Rn, and their confidence intervals (CIs), for each condition.

Design: Pressure-flow relationships were constructed in the supine and lateral recumbent positions (nonrapid eye movement [NREM] sleep, n = 10) and in the supine position (rapid eye movement [REM] sleep, n = 5).

Setting: University Hospital Antwerp, Belgium.

Patients: Ten obese patients (body mass index, 32.0 ± 5.6 kg/m2) with severe OSA (respiratory disturbance index, 63.0 ± 14.6 events/h) were studied.

Interventions: Pressure-flow relationships were constructed from breaths obtained during a series of step decreases in nasal pressure (34.1 ± 6.5 runs over 3.6 ± 1.2 h) in NREM sleep and during 7.8 ± 2.2 runs over 0.8 ± 0.6 h in REM sleep.

Results: Maximal inspiratory airflow reached a steady state in the third through fifth breaths following a decrease in nasal pressure. Analysis of pressure-flow relationships derived from these breaths showed that Pcrit fell from 1.8 (95% CI,− 0.1 to 2.7) cm H2O in the supine position to −1.1 cm H2O (95% CI, −1.8 to 0.4 cm H2O; p = 0.009) in the lateral recumbent position, whereas Rn did not change significantly. In contrast, no significant effect of sleep stage was found on either Pcrit or Rn.

Conclusions: Our methods for delineating upper airway pressure-flow relationships during sleep allow for multiple determinations of Pcrit within a single night from which small yet significant differences can be discerned between study conditions.

Figures in this Article

Sign In to Access Full Content

MEMBER & INDIVIDUAL SUBSCRIBER

Want Access?

NEW TO CHEST?

Become a CHEST member and receive a FREE subscription as a benefit of membership.

Individuals can purchase this article on ScienceDirect.

Individuals can purchase a subscription to the journal.

Individuals can purchase a subscription to the journal or buy individual articles.

Learn more about membership or Purchase a Full Subscription.

INSTITUTIONAL ACCESS

Institutional access is now available through ScienceDirect and can be purchased at myelsevier.com.

Sign In to Access Full Content

MEMBER & INDIVIDUAL SUBSCRIBER

Want Access?

NEW TO CHEST?

Become a CHEST member and receive a FREE subscription as a benefit of membership.

Individuals can purchase this article on ScienceDirect.

Individuals can purchase a subscription to the journal.

Individuals can purchase a subscription to the journal or buy individual articles.

Learn more about membership or Purchase a Full Subscription.

INSTITUTIONAL ACCESS

Institutional access is now available through ScienceDirect and can be purchased at myelsevier.com.

Figures

Tables

References

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.

Sign In to Access Full Content

MEMBER & INDIVIDUAL SUBSCRIBER

Want Access?

NEW TO CHEST?

Become a CHEST member and receive a FREE subscription as a benefit of membership.

Individuals can purchase this article on ScienceDirect.

Individuals can purchase a subscription to the journal.

Individuals can purchase a subscription to the journal or buy individual articles.

Learn more about membership or Purchase a Full Subscription.

INSTITUTIONAL ACCESS

Institutional access is now available through ScienceDirect and can be purchased at myelsevier.com.

Related Content

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

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