Change search
ReferencesLink to record
Permanent link

Direct link
Adjusting tidal volume to stress index in an open lung condition optimizes ventilation and prevents overdistension in an experimental model of lung injury and reduced chest wall compliance
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Hedenstierna laboratory.
Show others and affiliations
2015 (English)In: Critical Care, ISSN 1364-8535, E-ISSN 1466-609X, Vol. 19, 9Article in journal (Refereed) Published
Abstract [en]

Introduction: The stress index ( SI), a parameter derived from the shape of the pressure-time curve, can identify injurious mechanical ventilation. We tested the hypothesis that adjusting tidal volume (VT) to a non-injurious SI in an open lung condition avoids hypoventilation while preventing overdistension in an experimental model of combined lung injury and low chest-wall compliance (Ccw). Methods: Lung injury was induced by repeated lung lavages using warm saline solution, and Ccw was reduced by controlled intra-abdominal air-insufflation in 22 anesthetized, paralyzed and mechanically ventilated pigs. After injury animals were recruited and submitted to a positive end-expiratory pressure (PEEP) titration trial to find the PEEP level resulting in maximum compliance. During a subsequent four hours of mechanical ventilation, VT was adjusted to keep a plateau pressure (Pplat) of 30 cmH2O (Pplat-group, n = 11) or to a SI between 0.95 and 1.05 (SI-group, n = 11). Respiratory rate was adjusted to maintain a 'normal' PaCO2 (35 to 65 mmHg). SI, lung mechanics, arterial-blood gases haemodynamics pro-inflammatory cytokines and histopathology were analyzed. In addition Computed Tomography (CT) data were acquired at end expiration and end inspiration in six animals. Results: PaCO2 was significantly higher in the Pplat-group (82 versus 53 mmHg, P = 0.01), with a resulting lower pH (7.19 versus 7.34, P = 0.01). We observed significant differences in VT (7.3 versus 5.4 mlKg-1, P = 0.002) and Pplat values (30 versus 35 cmH2O, P = 0.001) between the Pplat-group and SI-group respectively. SI (1.03 versus 0.99, P = 0.42) and end-inspiratory transpulmonary pressure (PTP) (17 versus 18 cmH2O, P = 0.42) were similar in the Pplat-and SI-groups respectively, without differences in overinflated lung areas at end-inspiration in both groups. Cytokines and histopathology showed no differences. Conclusions: Setting tidal volume to a non-injurious stress index in an open lung condition improves alveolar ventilation and prevents overdistension without increasing lung injury. This is in comparison with limited Pplat protective ventilation in a model of lung injury with low chest-wall compliance.

Place, publisher, year, edition, pages
2015. Vol. 19, 9
National Category
Anesthesiology and Intensive Care
URN: urn:nbn:se:uu:diva-251854DOI: 10.1186/s13054-014-0726-3ISI: 000351853500001OAI: diva2:808252
Available from: 2015-04-27 Created: 2015-04-24 Last updated: 2015-04-27Bibliographically approved

Open Access in DiVA

fulltext(1544 kB)36 downloads
File information
File name FULLTEXT01.pdfFile size 1544 kBChecksum SHA-512
Type fulltextMimetype application/pdf

Other links

Publisher's full text

Search in DiVA

By author/editor
Suarez-Sipmann, Fernando
By organisation
Hedenstierna laboratory
In the same journal
Critical Care
Anesthesiology and Intensive Care

Search outside of DiVA

GoogleGoogle Scholar
Total: 36 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 227 hits
ReferencesLink to record
Permanent link

Direct link