Effect of Periodic Alveolar Recruitment Maneuvers on Intraoperative Atelectasis and Dynamic Respiratory Mechanics Assessed by Lung Ultrasound in Adult Patients Undergoing Elective Lumbar Spine Surgery in the Prone Position: A Randomized Controlled Trial
试验速览
- 阶段
- 不适用
- 状态
- 尚未招募
- 发起方
- 入组人数
- 60
- 主要终点
- Incidence of Significant Intraoperative Atelectasis Assessed by Lung Ultrasound
研究概览
简要总结
During general anesthesia, especially when patients are placed in the prone (face-down) position for spine surgery, parts of the lungs may partially collapse. This condition, called atelectasis, can reduce oxygen levels and affect breathing during and after surgery. Although anesthesiologists routinely use a breathing technique known as an alveolar recruitment maneuver to reopen collapsed lung areas, performing this maneuver only once at the beginning of surgery may not be sufficient to keep the lungs open throughout longer procedures.
The purpose of this study is to determine whether performing alveolar recruitment maneuvers at regular intervals during surgery can better prevent lung collapse compared with performing a single maneuver at the start of surgery. The study will include adult patients undergoing elective lumbar spine surgery under general anesthesia in the prone position.
All participants will receive standard anesthesia care and a baseline alveolar recruitment maneuver after being positioned for surgery. Participants will then be randomly assigned to one of two groups. One group will receive additional alveolar recruitment maneuvers approximately once every hour during surgery, while the other group will not receive further recruitment maneuvers beyond the initial one. Lung aeration will be assessed using lung ultrasound, a non-invasive imaging method that does not involve radiation.
The main outcome of the study is the presence of significant lung collapse immediately before removal of the breathing tube at the end of surgery. Secondary outcomes include measurements of breathing mechanics, oxygen levels, and the occurrence of temporary drops in oxygen saturation. The results of this study may help determine the most effective way to maintain lung function during prone spine surgery and improve respiratory safety during anesthesia.
详细描述
Detailed Description
General anesthesia and mechanical ventilation are known to reduce functional residual capacity and promote the development of atelectasis, particularly during prolonged surgical procedures. The prone position, which is commonly required for lumbar spine surgery, may further exacerbate these effects by altering chest wall mechanics and increasing intraabdominal and intrathoracic pressures. Intraoperative atelectasis has been associated with impaired oxygenation and adverse respiratory outcomes in the perioperative period.
Alveolar recruitment maneuvers are routinely used in anesthetic practice to reopen collapsed lung units and improve lung aeration. However, evidence from pediatric populations suggests that a single recruitment maneuver followed by standard positive end-expiratory pressure may be insufficient to maintain lung aeration during prolonged prone positioning. Whether a strategy of repeated, periodic recruitment maneuvers provides additional benefit in adult patients undergoing prone spine surgery remains unclear.
This prospective, single-center, randomized controlled trial is designed to evaluate the effect of periodic intraoperative alveolar recruitment maneuvers on lung aeration and respiratory mechanics in adult patients undergoing elective lumbar spine surgery in the prone position. After induction of standardized general anesthesia and placement of the patient in the prone position, lung aeration will be assessed using lung ultrasound. Lung ultrasound is a bedside, radiation-free imaging modality that allows regional evaluation of lung aeration and detection of atelectasis through validated scoring systems.
All participants will receive a baseline ultrasound-guided alveolar recruitment maneuver after the initial lung ultrasound assessment in the prone position. Following this baseline intervention, participants will be randomized to one of two parallel groups. In the periodic recruitment group, alveolar recruitment maneuvers will be repeated at regular intervals during surgery, approximately once per hour. In the control group, no additional recruitment maneuvers will be performed beyond the initial baseline maneuver. Ventilation settings and anesthetic management will otherwise be standardized and consistent between groups.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Prevention
- 盲法
- Single (Outcomes Assessor)
盲法说明
Lung ultrasound examinations and outcome assessments will be performed by an investigator who is blinded to group allocation. The anesthesiology team providing intraoperative care and performing the recruitment maneuvers will not be blinded due to the nature of the intervention. Participants will be under general anesthesia and therefore will not be aware of group assignment.
入排标准
- 年龄范围
- 18 Years 至 65 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Adults aged 18 to 65 years
- •Scheduled for elective lumbar spine surgery under general anesthesia
- •Surgery planned to be performed in the prone position
- •Expected surgical duration of at least 90 minutes
- •American Society of Anesthesiologists (ASA) physical status I-II
- •Ability to provide written informed consent
排除标准
- •Body mass index (BMI) greater than 30 kg/m²
- •History of thoracic surgery
- •Known or suspected chronic pulmonary disease (e.g., chronic obstructive pulmonary disease, restrictive lung disease)
- •Clinically significant cardiac disease
- •Pregnancy or breastfeeding
- •Known airway anomalies
- •Intraoperative conversion to a surgical duration shorter than 90 minutes
- •Refusal or inability to provide informed consent
研究组 & 干预措施
Periodic Alveolar Recruitment Maneuver Group
Participants assigned to this arm will receive standard general anesthesia and mechanical ventilation. After placement in the prone position, a baseline ultrasound-guided alveolar recruitment maneuver will be performed in all participants. In this arm, additional alveolar recruitment maneuvers will be applied at regular intervals during surgery, approximately once every hour, in order to maintain lung aeration throughout the procedure.
干预措施: Alveolar Recruitment Maneuver (Procedure)
Single Baseline Alveolar Recruitment Maneuver Group
Participants assigned to this arm will receive standard general anesthesia and mechanical ventilation. After placement in the prone position, a single baseline ultrasound-guided alveolar recruitment maneuver will be performed. No additional alveolar recruitment maneuvers will be applied during the remainder of the surgical procedure, and ventilation will otherwise follow standard intraoperative management.
干预措施: Alveolar Recruitment Maneuver (Procedure)
结局指标
主要结局
Incidence of Significant Intraoperative Atelectasis Assessed by Lung Ultrasound
时间窗: Immediately before tracheal extubation at the end of surgery
Significant intraoperative atelectasis will be defined as the presence of lung consolidation detected by lung ultrasound, corresponding to a lung ultrasound aeration score of 2 or higher in at least one predefined lung region. Lung ultrasound examinations will be performed using a standardized scanning protocol, and images will be evaluated by an outcome assessor blinded to group allocation.
次要结局
- Peak Inspiratory Pressure(Intraoperatively, at predefined time points during surgery)
- Dynamic Lung Compliance(Intraoperatively, at predefined time points during surgery)
- Peripheral Oxygen Saturation(Intraoperatively and during early postoperative recovery (up to 30 minutes in the post-anesthesia care unit))
- Incidence of Oxygen Desaturation(Intraoperatively and during early postoperative recovery (up to 30 minutes in the post-anesthesia care unit))
研究者
SERAP KARACALAR
Professor of Anesthesiology and Reanimation
Prof. Dr. Cemil Tascıoglu Education and Research Hospital Organization