Articles |

Relative Occurrence of Flow Limitation and Snoring During Continuous Positive Airway Pressure Titration FREE TO VIEW

Indu Ayappa; Robert G. Norman; Jean-Jacques Hosselet; Roger A. Gruenke; Joyce A. Walsleben; David M. Rapoport
Author and Funding Information

Affiliations: From the Division of Pulmonary and Critical Care Medicine, Lenexa, KS.,  From the Division of New York University Medical Center, New York, NY and Nellcor Puritan Bennett, Lenexa, KS.

David M. Rapoport, MD, Department of Medicine, New York University Medical Center, 550 First Ave, New York, NY 10016

1998 by the American College of Chest Physicians

Chest. 1998;114(3):685-690. doi:10.1378/chest.114.3.685
Text Size: A A A
Published online


Objectives: To examine the relative temporal appearance of flow limitation and snoring during continuous positive airway pressure (CPAP) titration, compare their sensitivity as indicators of airway obstruction, and assess their relative utility as feedback variables for automatic titration of CPAP.

Design: Retrospective review of data.

Setting: University teaching hospital.

Patients: Fifty-three patients diagnosed as having obstructive sleep apnea or upper airway resistance syndrome undergoing CPAP titration.

Measurements and results: We used a prototype automatic CPAP device that adjusts pressure in response to apnea, snoring, and/or flow limitation. The present study takes advantage of the frequent automatic decreases in pressure from a therapeutic level, as well as any technicianinitiated decreases in pressure. We tabulated, for each pressure decrease of >0.4 cm H2O, the occurrences of snoring alone, flow limitation alone, or simultaneous appearance of both. Of 2,177 automatic pressure decreases, 64% resulted in flow limitation alone, 8% in snoring alone, and 22% in the simultaneous occurrence of both. Overall, 86% of decreases resulted in flow limitation alone or were simultaneous with snoring, whereas 30% of decreases resulted in snoring alone or were simultaneous with flow limitation. In 10 of 35 patients, snoring alone occurred in >10% of the pressure decreases. In all but 5 of 133 manual pressure decreases, flow limitation developed at or above the pressure at which snoring developed.

Conclusions: While detection of snoring occasionally provided additional information, overall flow limitation was the earliest indicator of obstruction during decreases in CPAP.




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.

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