Effect of End-inspiratory Pause on Gas Exchange During Mediastinal Mass Excision With CO2 Insufflation and One-lung Ventilation
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: EIP-first, EIP-later.
- Who it may be relevant to
- Registry conditions: Mediastinal Mass Requiring Video-assisted Surgical Excision. Basic parameters: 20 years — 80 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- South Korea
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Overview
" Mediastinal mass excision is typically performed via video-assisted thoracoscopic surgery (VATS). To secure a clear surgical field, the ipsilateral lung must be deflated, achieved through one-lung ventilation (OLV) and intrathoracic CO₂ insufflation. However, OLV increases intrapulmonary shunt due to continued perfusion of the non-ventilated lung, potentially leading to hypoxemia and hypercapnia. When performed in the supine position, gas exchange becomes more challenging compared to lateral decubitus due to limited gravitational redistribution of blood flow. Although CO₂ insufflation aids surgical exposure through passive lung deflation, it may also increase CVP and PCWP, reduce cardiac output, and raise PaCO₂, contributing to respiratory acidosis. End-inspiratory pause (EIP), a ventilatory setting that pauses airflow at end-inspiration, prolongs alveolar gas exchange and improves ventilation-perfusion matching. Prior studies show EIP can enhance gas exchange, reduce microatelectasis, and improve CO₂ clearance in patients with acute lung injury. We therefore aimed to assess the effect of EIP application during VATS mediastinal mass excicion.
Interventions
- Procedure EIP-first
EIP is applied for 20 minutes immediately after the initiation of one-lung ventilation, followed by conventional mechanical ventilation. - Procedure EIP-later
Conventional mechanical ventilation is applied for 20 minutes after the initiation of one-lung ventilation, followed by EIP application.
Primary outcome measures
- PaCO₂ at 20 minutes after each ventilation method [Time frame: PaCO₂ is assessed at 20 minutes after each ventilation method]
Eligibility criteria
Inclusion criteria
- Adult patients aged 20 to 80 years scheduled for video-assisted thoracoscopic mediastinal tumor resection.
- American Society of Anesthesiologists (ASA) physical status classification of II (patients with mild systemic disease) or III (patients with severe systemic disease limiting activity).
Exclusion criteria
- Moderate to severe chronic obstructive pulmonary disease (COPD) according to GOLD criteria: defined as FEV₁/FVC < 0.7 and FEV₁ ≤ 80% of predicted on pulmonary function testing.
- Diffusion capacity of the lung for carbon monoxide (DLCO) < 80% of predicted.
- History of pneumothorax or presence of bullae or blebs on preoperative imaging.
- Inability to read or understand the subject information sheet and consent form.
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Allocation
- Randomized
- Model
- Crossover
- Masking
- Triple blind
- Primary purpose
- Supportive care
Study locations
South Korea · 1 center
- Severance hospital — Seoul
Identifiers
NCT: NCT06956079 · 4-2025-0232