Airway closure in anesthetized infants and children: influence of inspiratory pressures and volumes.

2.50
Hdl Handle:
http://hdl.handle.net/2336/30559
Title:
Airway closure in anesthetized infants and children: influence of inspiratory pressures and volumes.
Authors:
Thorsteinsson, A; Werner, O; Jonmarker, C; Larsson, A
Citation:
Acta Anaesthesiol Scand. 2002, 46(5):529-36
Issue Date:
1-May-2002
Abstract:
BACKGROUND: Cyclic opening and closing of lung units during tidal breathing may be an important cause of iatrogenic lung injury. We hypothesized that airway closure is uncommon in children with healthy lungs when inspiratory pressures are kept low, but paradoxically may occur when inspiratory pressures are increased. METHODS: Elastic equilibrium volume (EEV) and closing capacity (CC) were measured with a tracer gas (SF(6)) technique in 11 anesthetized, muscle-relaxed, endotracheally intubated and artificially ventilated healthy children, aged 0.6-13 years. Airway closing was studied in a randomized order at two inflation pressures, +20 or +30 cmH(2)O, and CC and CC/EEV were calculated from the plots obtained when the lungs were exsufflated to -20 cmH(2)O. (CC/EEV >1 indicates that airway closure might occur during tidal breathing). Furthermore, a measure of uneven ventilation, multiple breath alveolar mixing efficiency (MBAME), was obtained. RESULTS: Airway closure within the tidal volume (CC/EEV >1) was observed in four and eight children (not significant, NS) after 20 and 30 cmH(2)O inflation, respectively. However, CC(30)/EEV was >CC(20)/EEV in all children (P< or = 0.001). The MBAME was 75+/-7% (normal) and did not correlate with CC/EEV. CONCLUSION: Airway closure within tidal volumes may occur in artificially ventilated healthy children during ventilation with low inspiratory pressure. However, the risk of airway closure and thus opening within the tidal volume increases when the inspiratory pressures are increased.
Description:
To access publisher full text version of this article. Please click on the hyperlink in Additional Links field
Additional Links:
http://www.blackwell-synergy.com/doi/abs/10.1034/j.1399-6576.2002.460510.x

Full metadata record

DC FieldValue Language
dc.contributor.authorThorsteinsson, A-
dc.contributor.authorWerner, O-
dc.contributor.authorJonmarker, C-
dc.contributor.authorLarsson, A-
dc.date.accessioned2008-06-27T11:49:23Z-
dc.date.available2008-06-27T11:49:23Z-
dc.date.issued2002-05-01-
dc.date.submitted2008-06-27-
dc.identifier.citationActa Anaesthesiol Scand. 2002, 46(5):529-36en
dc.identifier.issn0001-5172-
dc.identifier.pmid12027847-
dc.identifier.doi10.1034/j.1399-6576.2002.460510.x-
dc.identifier.urihttp://hdl.handle.net/2336/30559-
dc.descriptionTo access publisher full text version of this article. Please click on the hyperlink in Additional Links fielden
dc.description.abstractBACKGROUND: Cyclic opening and closing of lung units during tidal breathing may be an important cause of iatrogenic lung injury. We hypothesized that airway closure is uncommon in children with healthy lungs when inspiratory pressures are kept low, but paradoxically may occur when inspiratory pressures are increased. METHODS: Elastic equilibrium volume (EEV) and closing capacity (CC) were measured with a tracer gas (SF(6)) technique in 11 anesthetized, muscle-relaxed, endotracheally intubated and artificially ventilated healthy children, aged 0.6-13 years. Airway closing was studied in a randomized order at two inflation pressures, +20 or +30 cmH(2)O, and CC and CC/EEV were calculated from the plots obtained when the lungs were exsufflated to -20 cmH(2)O. (CC/EEV >1 indicates that airway closure might occur during tidal breathing). Furthermore, a measure of uneven ventilation, multiple breath alveolar mixing efficiency (MBAME), was obtained. RESULTS: Airway closure within the tidal volume (CC/EEV >1) was observed in four and eight children (not significant, NS) after 20 and 30 cmH(2)O inflation, respectively. However, CC(30)/EEV was >CC(20)/EEV in all children (P< or = 0.001). The MBAME was 75+/-7% (normal) and did not correlate with CC/EEV. CONCLUSION: Airway closure within tidal volumes may occur in artificially ventilated healthy children during ventilation with low inspiratory pressure. However, the risk of airway closure and thus opening within the tidal volume increases when the inspiratory pressures are increased.en
dc.language.isoenen
dc.publisherBlackwell Munksgaarden
dc.relation.urlhttp://www.blackwell-synergy.com/doi/abs/10.1034/j.1399-6576.2002.460510.xen
dc.subject.meshAdolescenten
dc.subject.meshAir Pressureen
dc.subject.meshAirway Obstructionen
dc.subject.meshCalibrationen
dc.subject.meshChilden
dc.subject.meshChild, Preschoolen
dc.subject.meshElasticityen
dc.subject.meshFemaleen
dc.subject.meshFunctional Residual Capacityen
dc.subject.meshHumansen
dc.subject.meshInfanten
dc.subject.meshIntraoperative Complicationsen
dc.subject.meshLung Volume Measurementsen
dc.subject.meshMaleen
dc.subject.meshRespiration, Artificialen
dc.subject.meshSulfur Hexafluorideen
dc.titleAirway closure in anesthetized infants and children: influence of inspiratory pressures and volumes.en
dc.typeArticleen
dc.contributor.departmentDepartment of Anesthesia and Intensive Care, Landspitalinn University Hospital, Hringbraut, Iceland. adalbjn@landspitali.isen
dc.identifier.journalActa anaesthesiologica Scandinavicaen

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