Atelectasis, Postoperative Pulmonary Complications
Conditions
Keywords
Inspired oxygen concentration, One-lung ventilation, Lung recruitment maneuver
Brief summary
This study aims to investigate whether using 50% FiO₂ during one-lung ventilation, compared with 100% FiO₂, reduces postoperative atelectasis in the non-dependent (healthy) lung of patients undergoing VATS pulmonary lobectomy, based on individualized PEEP titration. This is a single-center, prospective, assessor- and patient-blinded randomized controlled trial. A total of 100 patients (50 per group, including a pilot phase of 10 per group) will be enrolled and randomized 1:1 to the high-oxygen group (FiO₂=100%) and the low-oxygen group (FiO₂=50%). The primary endpoint is the percentage of atelectasis volume in the non-operated lung relative to the total non-operated lung volume, assessed by CT at 60±10 minutes after tracheal extubation.
Interventions
PROCEDURELow inspired oxygen concentration (FiO₂=50%) during one-lung ventilation
Ventilation with initial FiO₂=50% during one-lung ventilation, combined with individualized PEEP titration. Oxygen concentration is dynamically adjusted based on SpO₂; ventilation duration at each FiO₂ level and total oxygen exposure burden are recorded.
PROCEDUREHigh inspired oxygen concentration (FiO₂=100%) during one-lung ventilaion
Ventilation with FiO₂=100% throughout one-lung ventilation, combined with individualized PEEP titration (decremental PEEP titration selecting the highest PEEP corresponding to the lowest driving pressure).
Sponsors
Peking University People's Hospital
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
DOUBLE (Subject, Outcomes Assessor)
Masking description
Patients are blinded pre- and postoperatively; postoperative data collectors, CT readers, and biostatisticians are blinded to allocation; only the attending anesthesiologist is unblinded due to the nature of the intervention (setting FiO₂), but does not participate in data collection or outcome assessment
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
No
Inclusion criteria
Age 18-65 years Elective thoracoscopic (VATS) pulmonary lobectomy Anticipated one-lung ventilation duration \>1 hour ASA physical status I-III
Exclusion criteria
Previous pulmonary surgery (including lobectomy, lung volume reduction surgery, or other lung resection) Pre-existing significant atelectasis (large collapse on preoperative CT) Contraindications to PEEP: intracranial hypertension, bronchopleural fistula, hypovolemic shock, right heart failure, giant bullae, pneumothorax Preoperative continuous oxygen therapy or mechanical ventilation, moderate-severe COPD BMI ≥ 30 kg/m² Ischemic cardiovascular and cerebrovascular diseases, such as myocardial infarction, ischemic stroke, and patients with coronary or cerebrovascular stents Patient refusal to participate Withdrawal Criteria / Major Protocol Deviations: Surgery changed to simple wedge resection Severe pleural adhesions (found intraoperatively) One-lung ventilation duration \< 50 minutes Intraoperative blood loss \> 500 ml Severe hypotension (MAP \< 55 mmHg despite high-dose vasopressors) Unexpected non-thoracic surgical procedure Ventilation protocol interrupted (e.g., FiO₂ exposure \< 80% of planned time in the low-oxygen group) Postoperative CT not completed or image quality unusable Subject withdrawal of informed consent
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Non-operated lung atelectasis volume percentage | CT scans were performed at 60 ± 10 minutes after tracheal extubation to assess the volume ratio of atelectasis in the contralateral lung. | Chest CT at 60±10 minutes after tracheal extubation |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Incidence of intraoperative adverse events | Intraoperative (from induction to emergence) | Incidence of intraoperative adverse events including hypoxemia (SpO₂ \< 90%), hypotension (MAP decreased \> 20% from baseline for \> 3 minutes), new-onset arrhythmia, and cerebral oxygen desaturation (rSO₂ \< 50% or \> 20% decrease from baseline) |
| Oxidative stress marker (MDA) | 1 hour after one lung ventilation | Arterial blood malondialdehyde (MDA) level at 1 hour after one lung ventilation |
| Postoperative renal function (serum creatinine and eGFR) | Postoperative days 1 and 3 | Serum creatinine (SCr) and estimated glomerular filtration rate (eGFR) to assess postoperative acute kidney injury |
| Intraoperative oxygen saturation | Intraoperative (during one lung ventilation) | Oxygen saturation (pulse oxygen) |
| Incidence of postoperative pulmonary complications | Postoperative days 1-3 | PPC defined as Melbourne Postoperative Pulmonary Complication score ≥4 |
| QoR-15 quality of recovery score | Postoperative days 1-3 | 15-item Quality of Recovery questionnaire score |
| Oxygen concentration exposure burden | Intraoperative (during one lung ventilation) | Sum of FiO₂ × time; incidence and frequency of FiO₂ increase |
| Arterial blood gas analysis (oxygenation index) | Multiple time points: (1) preoperative preparation room; (2) 5 minutes after two-lung ventilation at induction; (3) 5 minutes after one-lung ventilation start; (4) 1 hour after one-lung ventilation; (5) 10 minutes after tracheal extubation | PaO₂/FiO₂ ratio, PaO₂, PaCO₂, and pH at five predefined time points |
Countries
China
Contacts
CONTACTYi Feng, Ph.D
Outcome results
None listed