Scholarlink

Purpose <p>Passive leg raising (PLR) increases intrathoracic blood volume by redistributing blood from the lower to the upper body area. While inspiratory effort is hypothesized to have a similar effect due to pressure differences between the intrathoracic and extrathoracic cavities, direct evidence is scarce. Therefore, this study evaluated whether excessive inspiratory effort increases intrathoracic blood volume using end-expiratory lung impedance (EELI).</p> Methods <p>Volunteers, fitted with electrical impedance tomography (EIT) belts, underwent a spontaneous breathing procedure in the supine position (control step). They breathed through a specialized face mask with separated inspiration and expiration routes (one-way valves) and their EELI was continuously recorded. First, PLR was performed. Subsequently, resistors (3-mm and 2-mm) were sequentially added to the mask’s inspiration route, requiring volunteers to increase inspiratory effort. A reference EELI was established during spontaneous breathing, and changes in EELI (ΔEELI) were calculated for each step (control, PLR, 3-mm, and 2-mm). ΔEELI values were compared using the Friedman test and Wilcoxon signed-rank test with Holm’s <i>P</i> value adjustment.</p> Results <p>Across 11 participants, the mean ΔEELI decreased by 13, 18, and 19 units for PLR, 3-mm, and 2-mm resistors, respectively. The Friedman test and Wilcoxon signed-rank test revealed significant differences between the control and each aforementioned intervention.</p> Conclusion <p>PLR and increased inspiratory effort augment thoracic blood volume, thereby reducing EELI.</p> Registration <p>UMIN000054238. April/23/2024.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Inspiratory effort increases blood volume in the thoracic cavity and decreases end-expiratory lung impedance: a preliminary prospective study

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2025年4月3日

查看全文
  • Kazuhiro Takahashi,
  • Ayaka Koyama,
  • Daisuke Irimada,
  • Akihiro Kanaya,
  • Daisuke Konno,
  • Yu Kaiho,
  • Yusuke Takei,
  • Kazutomo Saito,
  • Yutaka Ejima,
  • Masanori Yamauchi

摘要

Purpose

Passive leg raising (PLR) increases intrathoracic blood volume by redistributing blood from the lower to the upper body area. While inspiratory effort is hypothesized to have a similar effect due to pressure differences between the intrathoracic and extrathoracic cavities, direct evidence is scarce. Therefore, this study evaluated whether excessive inspiratory effort increases intrathoracic blood volume using end-expiratory lung impedance (EELI).

Methods

Volunteers, fitted with electrical impedance tomography (EIT) belts, underwent a spontaneous breathing procedure in the supine position (control step). They breathed through a specialized face mask with separated inspiration and expiration routes (one-way valves) and their EELI was continuously recorded. First, PLR was performed. Subsequently, resistors (3-mm and 2-mm) were sequentially added to the mask’s inspiration route, requiring volunteers to increase inspiratory effort. A reference EELI was established during spontaneous breathing, and changes in EELI (ΔEELI) were calculated for each step (control, PLR, 3-mm, and 2-mm). ΔEELI values were compared using the Friedman test and Wilcoxon signed-rank test with Holm’s P value adjustment.

Results

Across 11 participants, the mean ΔEELI decreased by 13, 18, and 19 units for PLR, 3-mm, and 2-mm resistors, respectively. The Friedman test and Wilcoxon signed-rank test revealed significant differences between the control and each aforementioned intervention.

Conclusion

PLR and increased inspiratory effort augment thoracic blood volume, thereby reducing EELI.

Registration

UMIN000054238. April/23/2024.