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

Tracking of the within-breath changes of respiratory mechanics using the forced oscillation technique may provide outcomes that characterise the dynamic behaviour of the airways during normal breathing.We measured respiratory resistance (Rrs) and reactance (Xrs) at 8 Hz in 55 chronic obstructive pulmonary disease (COPD) patients and 20 healthy controls, and evaluated Rrs and Xrs as functions of gas flow (V′) and volume (V) during normal breathing cycles. In 12 COPD patients, additional measurements were made at continuous positive airway pressure (CPAP) levels of 4, 8, 14 and 20 hPa.The Rrs and Xrsversus V′ and V relationships displayed a variety of loop patterns, allowing characterisation of physiological and pathological processes. The main outcomes emerging from the within-breath analysis were the Xrsversus V loop area (AXV) quantifying expiratory flow limitation, and the tidal change in Xrs during inspiration (ΔXI) reflecting alteration in lung inhomogeneity in COPD. With increasing CPAP, AXV and ΔXI approached the normal ranges, although with a large variability between individuals, whereas mean Rrs remained unchanged.Within-breath tracking of Rrs and Xrs allows an improved assessment of expiratory flow limitation and functional inhomogeneity in COPD; thereby it may help identify the physiological phenotypes of COPD and determine the optimal level of respiratory support.

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Bench Evaluation of Flow Limitation Detection by Automated Continuous Positive Airway Pressure Device

CHEST Journal ◽

10.1378/chest.130.2.343 ◽

2006 ◽

Vol 130 (2) ◽

pp. 343-349 ◽

Cited By ~ 22

Author(s):

Frédéric Lofaso ◽

Gilbert Desmarais ◽

Karl Leroux ◽

Vincent Zalc ◽

Redouane Fodil ◽

...

Keyword(s):

Continuous Positive Airway Pressure ◽

Airway Pressure ◽

Positive Airway Pressure ◽

Flow Limitation

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Continuous Positive Airway Pressure (CPAP) Therapy for the Treatment of Hypernasality: A Single Case Study

Perspectives on Speech Science and Orofacial Disorders ◽

10.1044/ssod24.2.48 ◽

2014 ◽

Vol 24 (2) ◽

pp. 48-58 ◽

Cited By ~ 3

Author(s):

Lakshmi Kollara ◽

Graham Schenck ◽

Jamie Perry

Keyword(s):

Continuous Positive Airway Pressure ◽

Airway Pressure ◽

Positive Airway Pressure ◽

Single Case ◽

Treatment Method ◽

Post Treatment ◽

Subjective Perception ◽

Cpap Therapy ◽

Long Term Follow Up

Studies have investigated the applications of Continuous Positive Airway Pressure (CPAP) therapy in the treatment of hypernasality due to velopharyngeal dysfunction (VPD; Cahill et al., 2004; Kuehn, 1991; Kuehn, Moon, & Folkins, 1993; Kuehn et al., 2002). The purpose of this study was to examine the effectiveness of CPAP therapy to reduce hypernasality in a female subject, post-traumatic brain injury (TBI) and pharyngeal flap, who presented with signs of VPD including persistent hypernasality. Improvements in mean velopharyngeal orifice size, subjective perception of hypernasality, and overall intelligibility were observed from the baseline to 8-week post-treatment assessment intervals. Additional long-term assessments completed at 2, 3, and 4 months post-treatment indicated decreases in immediate post-treatment improvements. Results from the present study suggest that CPAP is a safe, non-invasive, and relatively conservative treatment method for reduction of hypernasality in selected patients with TBI. More stringent long-term follow up may indicate the need for repeated CPAP treatment to maintain results.

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