Journal article
Biomechanical Implications of Mass Loading in a Swine Model of Acute Hypoxemic Respiratory Failure
Journal of applied physiology (1985), Vol.139(3), pp.849-862
09/01/2025
DOI: 10.1152/japplphysiol.00377.2025
PMID: 40864615
Abstract
In obesity, excess weight of the chest and abdomen (mass loading) decreases lung volume and can worsen acute hypoxemic respiratory failure (AHRF). We investigated whether positive end-expiratory pressure (PEEP) fully reverses the effects of mass loading on lung volume and respiratory mechanics in an AHRF swine model. Eighteen Yorkshire pigs were studied: six healthy, eight pre- and post-injury, and four post-injury only. We randomly tested three mass loading conditions: without mass loading, with abdominal loading (6kg weight), and with combined abdominal and chest mass loading (12kg total weight). We performed a recruitment maneuver in each condition followed by a decremental PEEP trial and identified the best-PEEP as that with the greatest respiratory system compliance (C
). Airway pressure, esophageal pressure, and thoracic impedance by electrical impedance tomography) were continuously monitored. After lung injury, best-PEEP increased with loading. C
at best-PEEP decreased from 20.6 ± 3.4 ml/cmH
O without loading to 17.7 ± 3.0 ml/cmH
O with abdominal loading (mean difference 2.9, 95% CI 1.6-4.2) and to 14.2 ± 2.8 ml/cmH
O with abdominal and chest loading (mean difference 6.3, 95% CI 5.0-7.7). Any amount of loading decreased end-expiratory lung volume assessed by computed tomography (CT) at best-PEEP and PEEP 3 cmH
O. Combined abdominal-chest loading decreased the vertical lung dimension on CT compared to unloaded and abdominal loading at both levels of PEEP. With mass loading, PEEP did not restore values of C
and lung aeration to their unloaded values. In AHRF with mass loading, geometrical constraints may limit PEEP efficacy even when optimally titrated.
Details
- Title: Subtitle
- Biomechanical Implications of Mass Loading in a Swine Model of Acute Hypoxemic Respiratory Failure
- Creators
- Alice Nova - Harvard UniversityYi Xin - Mass General BrighamMarcus Victor - Mass General BrighamTimothy G Gaulton - Mass General BrighamGlasiele C Alcala - Mass General BrighamTilo Winkler - Mass General BrighamSarah E Gerard - University of IowaRehab Khalid - Mass General BrighamRajiv Gupta - Mass General BrighamEmanuele Rezoagli - Azienda Ospedaliera San GerardoLorenzo Berra - Mass General BrighamMarcelo B P Amato - Hospital das Clínicas da Faculdade de Medicina da Universidade de São PauloJason H T Bates - University of VermontMaurizio Cereda - Mass General Brigham
- Resource Type
- Journal article
- Publication Details
- Journal of applied physiology (1985), Vol.139(3), pp.849-862
- DOI
- 10.1152/japplphysiol.00377.2025
- PMID
- 40864615
- NLM abbreviation
- J Appl Physiol (1985)
- ISSN
- 8750-7587
- eISSN
- 1522-1601
- Publisher
- AMER PHYSIOLOGICAL SOC
- Grant note
- R01HL171199 / HHS | National Institutes of Health (NIH) R01HL137389 / HHS | National Institutes of Health (NIH)
- Language
- English
- Electronic publication date
- 08/27/2025
- Date published
- 09/01/2025
- Academic Unit
- Roy J. Carver Department of Biomedical Engineering; Anesthesia
- Record Identifier
- 9984958611702771
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