本文采用的英格恩产品: 增强型ECL发光液
Influence of ventilatory settings on pendelluft and expiratory muscle activity in hypoxemic patients resuming spontaneous breathing
Affiliations
- 1 Departamento de Medicina, Unidad de Pacientes Críticos, Hospital Clínico Universidad de Chile. Dr. Carlos Lorca Tobar 999, Independencia, Santiago, Chile. racornej@gmail.com.
- 2 Department of Intensive Care Adults, Erasmus MC University Medical Center, Rotterdam, The Netherlands. racornej@gmail.com.
- 3 Departamento de Medicina, Unidad de Pacientes Críticos, Hospital Clínico Universidad de Chile. Dr. Carlos Lorca Tobar 999, Independencia, Santiago, Chile.
- 4 Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Unity Health, Toronto, Canada.
- 5 Facultad de Medicina, Universidad de Chile, Santiago, Chile.
- 6 Unidade de Terapia Intensiva Adulto, Hospital das Clínicas Universidade Federal de Pernambuco, Recife, Brazil.
- 7 Divisao de Pneumologia, Faculdade de Medicina, Instituto do Coração, Hospital das Clinicas HCFMUSP, Universidade de São Paulo, São Paulo, Brazil.
- 8 Departamento de Kinesiología, Facultad de Medicina, Universidad de Chile, Santiago, Chile.
- 9 Departamento de Kinesiología, Facultad de Medicina, Universidad Andrés Bello, Santiago, Chile.
- 10 Departamento de Medicina Intensiva, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.
- 11 Department of Intensive Care Adults, Erasmus MC University Medical Center, Rotterdam, The Netherlands.
- 12 Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, ON, Canada.
- PMID: 41339937
- PMCID: PMC12781249
- DOI: 10.1186/s13054-025-05784-y
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.
Keywords: Acute respiratory distress syndrome; End-expiratory positive pressure; Expiratory muscle activation; Pendelluft; Pressure support ventilation.
