Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2010-2-1
pubmed:abstractText
Changes in end-expiratory lung volume (EELV) affect upper airway stability. The passive pharyngeal critical pressure (Pcrit), a measure of upper airway collapsibility, is determined using airway pressure drops. The EELV change during these drops has not been quantified and may differ between obese obstructive sleep apnea (OSA) patients and controls. Continuous positive airway pressure (CPAP)-treated OSA patients and controls were instrumented with an epiglottic catheter, magnetometers (to measure change in EELV), and a nasal mask/pneumotachograph. Subjects slept supine in a head-out plastic chamber in which the extrathoracic pressure could be lowered (to raise EELV) while on nasal CPAP. The magnitude of EELV change during Pcrit measurement (sudden reductions of CPAP for 3-5 breaths each minute) was assessed at baseline and with EELV increased approximately 500 ml. Fifteen OSA patients and 7 controls were studied. EELV change during Pcrit measurement was rapid and pressure dependent, but similar in OSA and control subjects (74 +/- 36 and 59 +/- 24 ml/cmH(2)O respectively, P = 0.33). Increased lung volume (mean +521 ml) decreased Pcrit by a similar amount in OSA and control subjects (-3.1 +/- 1.7 vs. -3.9 +/- 1.9 cmH(2)O, P = 0.31). Important lung volume changes occur during passive Pcrit measurement. However, on average, there is no difference in lung volume change for a given CPAP change between obese OSA subjects and controls. Changes in lung volume alter Pcrit substantially. This work supports a role for lung volume in the pathogenesis of OSA, and lung volume changes should be a consideration during assessment of pharyngeal mechanics.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
1522-1601
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
108
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
445-51
pubmed:meshHeading
pubmed-meshheading:19940097-Adult, pubmed-meshheading:19940097-Air Pressure, pubmed-meshheading:19940097-Anthropometry, pubmed-meshheading:19940097-Body Mass Index, pubmed-meshheading:19940097-Continuous Positive Airway Pressure, pubmed-meshheading:19940097-Female, pubmed-meshheading:19940097-Humans, pubmed-meshheading:19940097-Lung, pubmed-meshheading:19940097-Lung Compliance, pubmed-meshheading:19940097-Lung Volume Measurements, pubmed-meshheading:19940097-Male, pubmed-meshheading:19940097-Middle Aged, pubmed-meshheading:19940097-Obesity, pubmed-meshheading:19940097-Pharynx, pubmed-meshheading:19940097-Polysomnography, pubmed-meshheading:19940097-Respiratory Function Tests, pubmed-meshheading:19940097-Respiratory Mechanics, pubmed-meshheading:19940097-Sleep Apnea, Obstructive, pubmed-meshheading:19940097-Sleep Stages, pubmed-meshheading:19940097-Wakefulness
pubmed:year
2010
pubmed:articleTitle
The influence of end-expiratory lung volume on measurements of pharyngeal collapsibility.
pubmed:affiliation
Sleep Disorders Research Program, Div. of Sleep Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA. rowens@partners.org
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural