Effect of Periodic Alveolar Recruitment Maneuvers on Intraoperative Atelectasis in Adult Patients Undergoing Prone Lumbar Spine Surgery

NCT ID: NCT07325812

Last Updated: 2026-01-08

Basic Information

• Recruitment Status: NOT_YET_RECRUITING
• Clinical Phase: NA
• Total Enrollment: 60 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2026-01-31
• Study Completion Date: 2026-06-30

Brief Summary

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.

Detailed Description

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.

Lung ultrasound examinations will be performed at predefined intraoperative time points by an investigator who is blinded to group allocation. Lung aeration will be quantified using a standardized lung ultrasound scoring approach, allowing comparison of the incidence and severity of atelectasis between groups. In addition to lung ultrasound findings, intraoperative respiratory mechanics, including peak inspiratory pressure and dynamic lung compliance, will be recorded at predefined time points. Oxygen saturation will be monitored continuously, and episodes of oxygen desaturation will be documented.

The primary objective of the study is to compare the incidence of significant intraoperative atelectasis between patients receiving periodic alveolar recruitment maneuvers and those receiving a single baseline maneuver. Secondary objectives include evaluation of differences in respiratory mechanics, oxygenation parameters, and the occurrence of transient intraoperative or early postoperative respiratory events. Safety outcomes related to recruitment maneuvers, such as transient hypotension or oxygen desaturation, will also be monitored.

By assessing lung aeration with lung ultrasound and focusing on a practical ventilation strategy that can be easily implemented during routine anesthesia care, this study aims to provide clinically relevant data on optimizing intraoperative respiratory management in adult patients undergoing prone lumbar spine surgery.

Conditions

Atelectasis; Mechanical Ventilation; General Anesthesia; Prone Position

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: PREVENTION
• Blinding Strategy: SINGLE

Study Groups

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.

Group Type: EXPERIMENTAL

Alveolar Recruitment Maneuver

Intervention Type: PROCEDURE

An alveolar recruitment maneuver will be applied under general anesthesia using a closed ventilatory system. Following prone positioning, a baseline recruitment maneuver will be performed by applying continuous positive airway pressure of approximately 30-40 cmH₂O for 5-10 seconds. Depending on group assignment, the recruitment maneuver will either be repeated at regular intraoperative intervals (approximately once every hour) or applied only once as a single baseline maneuver.

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.

Group Type: ACTIVE_COMPARATOR

Alveolar Recruitment Maneuver

Intervention Type: PROCEDURE

An alveolar recruitment maneuver will be applied under general anesthesia using a closed ventilatory system. Following prone positioning, a baseline recruitment maneuver will be performed by applying continuous positive airway pressure of approximately 30-40 cmH₂O for 5-10 seconds. Depending on group assignment, the recruitment maneuver will either be repeated at regular intraoperative intervals (approximately once every hour) or applied only once as a single baseline maneuver.

Interventions

Alveolar Recruitment Maneuver

An alveolar recruitment maneuver will be applied under general anesthesia using a closed ventilatory system. Following prone positioning, a baseline recruitment maneuver will be performed by applying continuous positive airway pressure of approximately 30-40 cmH₂O for 5-10 seconds. Depending on group assignment, the recruitment maneuver will either be repeated at regular intraoperative intervals (approximately once every hour) or applied only once as a single baseline maneuver.

Intervention Type: PROCEDURE

Other Intervention Names

Lung Recruitment Maneuver

Eligibility Criteria

Inclusion Criteria

• 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

Exclusion Criteria

• 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

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 65 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Prof. Dr. Cemil Tascıoglu Education and Research Hospital Organization

OTHER

Sponsor Role: lead

Responsible Party

SERAP KARACALAR

Professor of Anesthesiology and Reanimation

Responsibility Role: PRINCIPAL_INVESTIGATOR

Other Identifiers

CTERHO-SOZER-LUS-ARM-PRONE-001

Identifier Type: -

Identifier Source: org_study_id