Influence of ventilatory settings on pendelluft and expiratory muscle activity in hypoxemic patients resuming spontaneous breathing

Rodrigo A. Cornejo; Roberto Brito; Carla Rivera; Caio C.A. Morais; Daniel H. Arellano; Marioli T. Lazo; Alejandro Fuentes; Eduardo Paredes; Verónica Rojas; María F. Bravo; María J. Martin; Luz Miranda; Juan N. Medel; Alejandro R. Bruhn; Jan Bakker; Marcelo B.P. Amato; Laurent J. Brochard; Nivia R. Estuardo

doi:10.1186/s13054-025-05784-y

Influence of ventilatory settings on pendelluft and expiratory muscle activity in hypoxemic patients resuming spontaneous breathing

Rodrigo A. Cornejo^*
, Roberto Brito
, Carla Rivera
, Caio C.A. Morais
, Daniel H. Arellano
, Marioli T. Lazo
, Alejandro Fuentes
, Eduardo Paredes
, Verónica Rojas
, María F. Bravo
, María J. Martin
, Luz Miranda
, Juan N. Medel
, Alejandro R. Bruhn
, Jan Bakker
, Marcelo B.P. Amato
, Laurent J. Brochard
, Nivia R. Estuardo

^*Corresponding author for this work

Intensive Care

Universidad de Chile
Erasmus University Rotterdam
University of Toronto
Universidade Federal de Pernambuco
Universidade de São Paulo
Universidad Andrés Bello
Pontificia Universidad Católica de Chile

Research output: Contribution to journal › Article › Academic › peer-review

4 Citations (Scopus)

10 Downloads (Pure)

Abstract

Background:

Pendelluft and expiratory muscle activity during spontaneous breathing should be minimized to reduce potential harmful effects. This study aimed to describe pendelluft and expiratory muscle activity in hypoxemic patients recovering spontaneous breathing after ≥ 72 h of lung-protective, fully controlled mechanical ventilation (MV) and assess the effect of pressure support ventilation (PSV) and positive end-expiratory pressure (PEEP).

Methods:

A physiological, randomized crossover study was conducted in hypoxemic patients receiving three levels of PSV: 5, 10, and 15 cmH₂O, and two PEEP levels: based on electrical impedance tomography before spontaneous breathing (PEEP_EIT) or according to PEEP-FiO₂ tables (PEEP_ARDS). Pendelluft was defined as the percentage of volume displaced from non-dependent to dependent lung regions during inspiration. Expiratory muscle activity was assessed by the expiratory rise in gastric pressure (ΔPga_EXP), and inspiratory effort was estimated using muscular pressure (Pmus). Statistical analyses included linear mixed-effects models and mediation analyses.

Results:

Fifteen patients were enrolled (mean PaO₂/FiO₂ ratio: 262 ± 51 mmHg; median duration of MV: 9 [5–13] days; 6 females). PEEP_EIT was 11 [10–13] cmH₂O and PEEP_ARDS 6 [5–7] cmH₂O. Expiratory muscle activity was observed in 13 patients. Compared to PS 5 cmH₂O, PS to 10 and 15 cmH₂O, adjusted for PEEP, significantly reduced both pendelluft and ΔPga_EXP (p < 0.001). When adjusted for PS, PEEP_EIT was associated with a slight reduction in pendelluft (p = 0.039) but a concomitant increase in ΔPga_EXP (p = 0.007) compared to PEEP_ARDS. The mediation analysis revealed a significant negative mediating effect of ΔPga_EXP on the relationship between PEEP_EIT and pendelluft (p < 0.001). Pmus, which was also significantly associated with pendelluft magnitude (p < 0.001), mediated the effect of PS on reducing pendelluft (p = 0.048), but not that of PEEP (p = 0.46).

Conclusions:

In patients with ARDS transitioning to spontaneous breathing, increasing PS reduces pendelluft and expiratory muscle activity. Higher PEEP can decrease pendelluft, but its effect can be counteracted by increased expiratory activity.

Original language	English
Article number	13
Journal	Critical Care
Volume	30
Issue number	1
DOIs	https://doi.org/10.1186/s13054-025-05784-y
Publication status	Published - 7 Jan 2026

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Publisher Copyright:
© The Author(s) 2025.

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Influence of ventilatory settings on pendelluft and expiratory muscle activity in hypoxemic patients resuming spontaneous breathingFinal published version, 1.49 MBLicence: CC BY-NC-ND

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Cornejo, R. A., Brito, R., Rivera, C., Morais, C. C. A., Arellano, D. H., Lazo, M. T., Fuentes, A., Paredes, E., Rojas, V., Bravo, M. F., Martin, M. J., Miranda, L., Medel, J. N., Bruhn, A. R., Bakker, J., Amato, M. B. P., Brochard, L. J., & Estuardo, N. R. (2026). Influence of ventilatory settings on pendelluft and expiratory muscle activity in hypoxemic patients resuming spontaneous breathing. Critical Care, 30(1), Article 13. https://doi.org/10.1186/s13054-025-05784-y

@article{ec3ce26d01e1463290546c5b1f185bfd,

title = "Influence of ventilatory settings on pendelluft and expiratory muscle activity in hypoxemic patients resuming spontaneous breathing",

abstract = "Background: Pendelluft and expiratory muscle activity during spontaneous breathing should be minimized to reduce potential harmful effects. This study aimed to describe pendelluft and expiratory muscle activity in hypoxemic patients recovering spontaneous breathing after ≥ 72 h of lung-protective, fully controlled mechanical ventilation (MV) and assess the effect of pressure support ventilation (PSV) and positive end-expiratory pressure (PEEP). Methods: A physiological, randomized crossover study was conducted in hypoxemic patients receiving three levels of PSV: 5, 10, and 15 cmH₂O, and two PEEP levels: based on electrical impedance tomography before spontaneous breathing (PEEPEIT) or according to PEEP-FiO2 tables (PEEPARDS). Pendelluft was defined as the percentage of volume displaced from non-dependent to dependent lung regions during inspiration. Expiratory muscle activity was assessed by the expiratory rise in gastric pressure (ΔPgaEXP), and inspiratory effort was estimated using muscular pressure (Pmus). Statistical analyses included linear mixed-effects models and mediation analyses.Results: Fifteen patients were enrolled (mean PaO2/FiO2 ratio: 262 ± 51 mmHg; median duration of MV: 9 [5–13] days; 6 females). PEEPEIT was 11 [10–13] cmH₂O and PEEPARDS 6 [5–7] cmH₂O. Expiratory muscle activity was observed in 13 patients. Compared to PS 5 cmH2O, PS to 10 and 15 cmH2O, adjusted for PEEP, significantly reduced both pendelluft and ΔPgaEXP (p < 0.001). When adjusted for PS, PEEPEIT was associated with a slight reduction in pendelluft (p = 0.039) but a concomitant increase in ΔPgaEXP (p = 0.007) compared to PEEPARDS. The mediation analysis revealed a significant negative mediating effect of ΔPgaEXP on the relationship between PEEPEIT and pendelluft (p < 0.001). Pmus, which was also significantly associated with pendelluft magnitude (p < 0.001), mediated the effect of PS on reducing pendelluft (p = 0.048), but not that of PEEP (p = 0.46).Conclusions: In patients with ARDS transitioning to spontaneous breathing, increasing PS reduces pendelluft and expiratory muscle activity. Higher PEEP can decrease pendelluft, but its effect can be counteracted by increased expiratory activity.",

author = "Cornejo, \{Rodrigo A.\} and Roberto Brito and Carla Rivera and Morais, \{Caio C.A.\} and Arellano, \{Daniel H.\} and Lazo, \{Marioli T.\} and Alejandro Fuentes and Eduardo Paredes and Ver{\'o}nica Rojas and Bravo, \{Mar{\'i}a F.\} and Martin, \{Mar{\'i}a J.\} and Luz Miranda and Medel, \{Juan N.\} and Bruhn, \{Alejandro R.\} and Jan Bakker and Amato, \{Marcelo B.P.\} and Brochard, \{Laurent J.\} and Estuardo, \{Nivia R.\}",

note = "Publisher Copyright: {\textcopyright} The Author(s) 2025.",

year = "2026",

month = jan,

day = "7",

doi = "10.1186/s13054-025-05784-y",

language = "English",

volume = "30",

journal = "Critical Care",

issn = "1364-8535",

publisher = "BioMed Central Ltd.",

number = "1",

}

Cornejo, RA, Brito, R, Rivera, C, Morais, CCA, Arellano, DH, Lazo, MT, Fuentes, A, Paredes, E, Rojas, V, Bravo, MF, Martin, MJ, Miranda, L, Medel, JN, Bruhn, AR, Bakker, J, Amato, MBP, Brochard, LJ & Estuardo, NR 2026, 'Influence of ventilatory settings on pendelluft and expiratory muscle activity in hypoxemic patients resuming spontaneous breathing', Critical Care, vol. 30, no. 1, 13. https://doi.org/10.1186/s13054-025-05784-y

TY - JOUR

T1 - Influence of ventilatory settings on pendelluft and expiratory muscle activity in hypoxemic patients resuming spontaneous breathing

AU - Cornejo, Rodrigo A.

AU - Brito, Roberto

AU - Rivera, Carla

AU - Morais, Caio C.A.

AU - Arellano, Daniel H.

AU - Lazo, Marioli T.

AU - Fuentes, Alejandro

AU - Paredes, Eduardo

AU - Rojas, Verónica

AU - Bravo, María F.

AU - Martin, María J.

AU - Miranda, Luz

AU - Medel, Juan N.

AU - Bruhn, Alejandro R.

AU - Bakker, Jan

AU - Amato, Marcelo B.P.

AU - Brochard, Laurent J.

AU - Estuardo, Nivia R.

PY - 2026/1/7

Y1 - 2026/1/7

N2 - Background: Pendelluft and expiratory muscle activity during spontaneous breathing should be minimized to reduce potential harmful effects. This study aimed to describe pendelluft and expiratory muscle activity in hypoxemic patients recovering spontaneous breathing after ≥ 72 h of lung-protective, fully controlled mechanical ventilation (MV) and assess the effect of pressure support ventilation (PSV) and positive end-expiratory pressure (PEEP). Methods: A physiological, randomized crossover study was conducted in hypoxemic patients receiving three levels of PSV: 5, 10, and 15 cmH₂O, and two PEEP levels: based on electrical impedance tomography before spontaneous breathing (PEEPEIT) or according to PEEP-FiO2 tables (PEEPARDS). Pendelluft was defined as the percentage of volume displaced from non-dependent to dependent lung regions during inspiration. Expiratory muscle activity was assessed by the expiratory rise in gastric pressure (ΔPgaEXP), and inspiratory effort was estimated using muscular pressure (Pmus). Statistical analyses included linear mixed-effects models and mediation analyses.Results: Fifteen patients were enrolled (mean PaO2/FiO2 ratio: 262 ± 51 mmHg; median duration of MV: 9 [5–13] days; 6 females). PEEPEIT was 11 [10–13] cmH₂O and PEEPARDS 6 [5–7] cmH₂O. Expiratory muscle activity was observed in 13 patients. Compared to PS 5 cmH2O, PS to 10 and 15 cmH2O, adjusted for PEEP, significantly reduced both pendelluft and ΔPgaEXP (p < 0.001). When adjusted for PS, PEEPEIT was associated with a slight reduction in pendelluft (p = 0.039) but a concomitant increase in ΔPgaEXP (p = 0.007) compared to PEEPARDS. The mediation analysis revealed a significant negative mediating effect of ΔPgaEXP on the relationship between PEEPEIT and pendelluft (p < 0.001). Pmus, which was also significantly associated with pendelluft magnitude (p < 0.001), mediated the effect of PS on reducing pendelluft (p = 0.048), but not that of PEEP (p = 0.46).Conclusions: In patients with ARDS transitioning to spontaneous breathing, increasing PS reduces pendelluft and expiratory muscle activity. Higher PEEP can decrease pendelluft, but its effect can be counteracted by increased expiratory activity.

AB - Background: Pendelluft and expiratory muscle activity during spontaneous breathing should be minimized to reduce potential harmful effects. This study aimed to describe pendelluft and expiratory muscle activity in hypoxemic patients recovering spontaneous breathing after ≥ 72 h of lung-protective, fully controlled mechanical ventilation (MV) and assess the effect of pressure support ventilation (PSV) and positive end-expiratory pressure (PEEP). Methods: A physiological, randomized crossover study was conducted in hypoxemic patients receiving three levels of PSV: 5, 10, and 15 cmH₂O, and two PEEP levels: based on electrical impedance tomography before spontaneous breathing (PEEPEIT) or according to PEEP-FiO2 tables (PEEPARDS). Pendelluft was defined as the percentage of volume displaced from non-dependent to dependent lung regions during inspiration. Expiratory muscle activity was assessed by the expiratory rise in gastric pressure (ΔPgaEXP), and inspiratory effort was estimated using muscular pressure (Pmus). Statistical analyses included linear mixed-effects models and mediation analyses.Results: Fifteen patients were enrolled (mean PaO2/FiO2 ratio: 262 ± 51 mmHg; median duration of MV: 9 [5–13] days; 6 females). PEEPEIT was 11 [10–13] cmH₂O and PEEPARDS 6 [5–7] cmH₂O. Expiratory muscle activity was observed in 13 patients. Compared to PS 5 cmH2O, PS to 10 and 15 cmH2O, adjusted for PEEP, significantly reduced both pendelluft and ΔPgaEXP (p < 0.001). When adjusted for PS, PEEPEIT was associated with a slight reduction in pendelluft (p = 0.039) but a concomitant increase in ΔPgaEXP (p = 0.007) compared to PEEPARDS. The mediation analysis revealed a significant negative mediating effect of ΔPgaEXP on the relationship between PEEPEIT and pendelluft (p < 0.001). Pmus, which was also significantly associated with pendelluft magnitude (p < 0.001), mediated the effect of PS on reducing pendelluft (p = 0.048), but not that of PEEP (p = 0.46).Conclusions: In patients with ARDS transitioning to spontaneous breathing, increasing PS reduces pendelluft and expiratory muscle activity. Higher PEEP can decrease pendelluft, but its effect can be counteracted by increased expiratory activity.

UR - https://www.scopus.com/pages/publications/105026966657

U2 - 10.1186/s13054-025-05784-y

DO - 10.1186/s13054-025-05784-y

M3 - Article

C2 - 41339937

AN - SCOPUS:105026966657

SN - 1364-8535

VL - 30

JO - Critical Care

JF - Critical Care

IS - 1

M1 - 13

ER -

Influence of ventilatory settings on pendelluft and expiratory muscle activity in hypoxemic patients resuming spontaneous breathing

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