OBJECTIVE: A large tidal volume (VT) and @entity891 and re-expansion may cause @entity21712 ( @entity21712 ) in @entity647 ( @entity647 ). A low VT and a positive end-expiratory pressure ( @entity9239 ) can prevent @entity21712 , but the more VT is reduced, the more dead space (VD) compromises gas exchange. We investigated how physiological, airway and @entity133 varied with @entity9239 and analysed possible links to respiratory mechanics. SETTING: Medical and surgical intensive care unit (ICU) in a university hospital. DESIGN: Prospective, non-randomised comparative trial. @entity1 . Ten consecutive @entity647 @entity1 . INTERVENTION: Stepwise increases in @entity9239 from zero to 15 cm @entity2507 . MEASUREMENTS AND RESULTS: Lung mechanics and VD were measured at each @entity9239 level. Physiological VD was 41-64% of VT at zero @entity9239 and increased slightly with @entity9239 due to a rise in airway VD. @entity133 was 11-38% of VT and did not vary systematically with @entity9239 . However, in individual @entity1 a decrease and increase of @entity133 paralleled a positive or negative response to @entity9239 with respect to oxygenation (shunt), respectively. VD fractions were independent of respiratory resistance and compliance. CONCLUSIONS: @entity133 is large and does not vary systematically with @entity9239 in @entity1 with various degrees of @entity647 . Individual measurements show a diverse response to @entity9239 . Respiratory mechanics were of no help in optimising @entity9239 with regard to gas exchange.

Effects of positive end-expiratory pressure on dead space and its partitions in XXXX .

@entity1 :: ('9606', 'Species') :: ['patients', 'PATIENTS'] @entity21712 :: ('MESH:D055397', 'Disease') :: ['VILI', 'ventilator-induced lung injury'] @entity133 :: ('MESH:D002282', 'Disease') :: ['Alveolar VD', 'alveolar VD'] @entity891 :: ('MESH:D001261', 'Disease') :: ['lung collapse'] @entity2507 :: ('CHEBI:33813', 'Chemical') :: ['H2O'] @entity9239 :: ('CHEBI:60683', 'Chemical') :: ['PEEP'] @entity647 :: ('MESH:D055371', 'Disease') :: ['acute lung injury', 'ALI']
@entity647 :: (MESH:D055371,Disease) :: ['acute lung injury']
