Linked Life Data

9787688

Source:http://linkedlifedata.com/resource/pubmed/id/9787688

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1998-11-25
pubmed:abstractText
Airway closure during mixed apneas in preterm infants may be due to lack of tone in the upper airway followed by collapse and obstruction or diaphragmatic action inducing obstruction. We examine whether respiratory efforts are necessary for airway closure using a new method of detecting airway obstruction, based on the disappearance of an amplified cardiac pulse observed on the respiratory flow tracing. We analyzed 198 episodes of mixed apnea of various lengths (> or = 3 seconds) observed in 33 preterm infants (birth weight, 1.4 +/- 0.1 kg [mean +/- SEM]; study weight, 1.7 +/- 0.1 kg; gestational age, 29 +/- 1 weeks; post-natal age, 33 +/- 4 days). The great majority of these episodes (88%) had a central, followed by an obstructive, component. Infants were studied by using a nosepiece and a flow-through system. Respiratory efforts (abdominal and chest movements) were recorded. Of the apneas, 20 were < 5 seconds; 78, 5 to < 10 seconds; 45, 10 to < 15 seconds; 27, 15 to < 20 seconds; and 28, > or = 20 seconds. Of the 198 mixed apneas, 151 (76%) occurred in the absence of any respiratory effort; 43 (22%) showed a simultaneous cessation of the cardiac oscillation and respiratory effort; and 4 (2%) showed diaphragmatic activity appearing after cessation of the cardiac oscillation (airway occlusion). Respiratory efforts never preceded the cessation of the cardiac oscillation. The findings suggest that diaphragmatic action is not needed to occlude the airway in mixed apneas. The simultaneous cessation of cardiac oscillations (airway occlusion) and onset of respiratory efforts may indicate that such effort contributes to closure or is induced by the same stimulus that closes the airway. We speculate that the mechanism for airway closure in mixed apneas is most likely a lack of upper airway tone, which normally occurs with the cessation of a central drive to breathe.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0022-3476
pubmed:author
pubmed:issnType
Print
pubmed:volume
133
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
509-12
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Airway closure during mixed apneas in preterm infants: is respiratory effort necessary?
pubmed:affiliation
Department of Pediatrics, University of Manitoba, Winnipeg, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't