Effect of Inspired Oxygen Concentration on Postoperative Atelectasis After VATS Lobectomy

N/ANot Yet RecruitingNCT07721558

Peking University People's Hospital100 enrolled

Overview

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.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

DOUBLE

Enrollment

100

Conditions

Atelectasis Postoperative Pulmonary Complications

Interventions

High inspired oxygen concentration (FiO₂=100%) during one-lung ventilaionPROCEDURE

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).

Eligibility

Sex: ALLMin age: 18 YearsMax age: 65 Years

Medical Language ↔ Plain English

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

Outcomes

Primary Outcomes

Non-operated lung atelectasis volume percentage

Chest CT at 60±10 minutes after tracheal extubation

Time frame: CT scans were performed at 60 ± 10 minutes after tracheal extubation to assess the volume ratio of atelectasis in the contralateral lung.

Secondary Outcomes

Incidence of postoperative pulmonary complications

PPC defined as Melbourne Postoperative Pulmonary Complication score ≥4

Time frame: Postoperative days 1-3

QoR-15 quality of recovery score

15-item Quality of Recovery questionnaire score

Time frame: Postoperative days 1-3

Arterial blood gas analysis (oxygenation index)

PaO₂/FiO₂ ratio, PaO₂, PaCO₂, and pH at five predefined time points

Time frame: 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

Intraoperative oxygen saturation

Oxygen saturation (pulse oxygen)

Time frame: Intraoperative (during one lung ventilation)

Oxygen concentration exposure burden

Sum of FiO₂ × time; incidence and frequency of FiO₂ increase

Time frame: Intraoperative (during one lung ventilation)

Incidence of intraoperative adverse events

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)

Time frame: Intraoperative (from induction to emergence)

Oxidative stress marker (MDA)

Arterial blood malondialdehyde (MDA) level at 1 hour after one lung ventilation

Time frame: 1 hour after one lung ventilation

Postoperative renal function (serum creatinine and eGFR)

Serum creatinine (SCr) and estimated glomerular filtration rate (eGFR) to assess postoperative acute kidney injury

Time frame: Postoperative days 1 and 3