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Image Acquisition Method for the Sonographic Assessment of the Inferior Vena Cava
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Inferior vena cava respiratory variability changes during jet ventilation in rigid bronchoscopy: a prospective
Mingyuan Yang1,2, Yuxue Yao2, Hong Li2
1Department of Anesthesiology, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China.
BMC Anesthesiology
|July 2, 2026
Summary
Inferior vena cava (IVC) respiratory variability significantly decreases during rigid bronchoscopy with jet ventilation. This suggests IVC indices are unreliable for assessing fluid status in this specific ventilatory setting.
Area of Science:
- Critical Care Medicine
- Anesthesiology
- Cardiovascular Physiology
Background:
- Inferior vena cava (IVC) respiratory variability is a common method for assessing fluid responsiveness.
- Its interpretation is context-dependent, especially during specific ventilatory techniques like jet ventilation used in rigid bronchoscopy.
- The impact of jet ventilation on IVC-derived indices is not well understood.
Purpose of the Study:
- To investigate the changes in IVC-derived respiratory variability during rigid bronchoscopy.
- To evaluate the effect of transitioning from mask-assisted positive-pressure ventilation to open jet ventilation on IVC parameters.
- To determine the reliability of IVC indices for fluid status assessment in this context.
Main Methods:
- A prospective, self-controlled observational study involving 60 adult patients undergoing rigid bronchoscopy.
- Measurements of IVC parameters using M-mode ultrasonography were taken at three time points: baseline, mask ventilation, and jet ventilation.
- The primary outcome was the change in IVC distensibility index (dIVC) between mask and jet ventilation phases.
Main Results:
- The IVC distensibility index (dIVC) significantly decreased from 86.29% during mask ventilation to 22.08% during jet ventilation (P < 0.001).
- A large effect size (Cohen's d = 1.79) was observed for the change in dIVC.
- Changes included increased minimum IVC diameter and reduced IVC diameter variation, while heart rate and mean arterial pressure remained stable.
Conclusions:
- Transitioning to open jet ventilation during rigid bronchoscopy causes a marked change in IVC-derived respiratory variability.
- IVC indices are sensitive to ventilation mode and airway openness, questioning their utility for direct intravascular volume status assessment in this scenario.
- Conventional IVC interpretation thresholds should be used cautiously during open jet ventilation due to altered physiological conditions.
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