Effects of Periodic Recruitment Maneuvers on Atelectasis and Respiratory Mechanics During Elective Spine Surgery Assessed by Lung Ultrasonography

NCT07325812 | Recruiting

• 1 other identifier: CTERHO-SOZER-LUS-ARM-PRONE-001
• Study Type: interventional
• Target: 60
• Locations: 1 country
• Sites: 1

Brief Summary

During general anesthesia, particularly in patients undergoing spine surgery in the prone (face-down) position, increased intrathoracic and abdominal pressure may reduce lung compliance and promote the development of atelectasis (partial lung collapse). Atelectasis can impair intraoperative oxygenation and may increase the risk of postoperative pulmonary complications. Alveolar recruitment maneuvers (ARM) are routinely used in anesthesia practice to reopen collapsed lung regions; however, it remains unclear whether periodic application of ARM throughout surgery provides additional benefit compared with standard single-time application. This prospective, randomized controlled clinical study aims to evaluate whether periodic alveolar recruitment maneuvers applied during elective spine surgery in the prone position reduce intraoperative atelectasis and improve respiratory mechanics compared with the standard approach of performing ARM only after positioning and before extubation. Adult patients undergoing elective spine surgery under general anesthesia will be randomly assigned to either a periodic ARM group or a standard ARM group. Lung aeration will be assessed using lung ultrasound, a non-invasive and radiation-free bedside imaging method. The primary outcome is the incidence of intraoperative atelectasis assessed before extubation. Secondary outcomes include lung ultrasound aeration scores, respiratory mechanics parameters (such as airway pressures and compliance), oxygenation indices, and the occurrence of transient intraoperative respiratory or hemodynamic events. The findings of this study may help optimize intraoperative ventilation strategies in prone spine surgery and contribute to improved perioperative respiratory safety.

Conditions

Prone Position; General Anesthesia; Atelectasis; Mechanical Ventilation

Keywords

Atelectasis; Alveolar Recruitment Maneuver; Lung Ultrasound; Prone Position; Respiratory Mechanics

Outcome Measures

Primary Outcomes (1)

• Incidence of Significant Intraoperative Atelectasis Assessed by Lung Ultrasound

  Significant intraoperative atelectasis will be defined as the presence of significant loss of lung aeration identified by transthoracic lung ultrasound, corresponding to a regional score of 2 or higher in at least one predefined lung region using a standardized 12-region semi-quantitative lung ultrasound aeration scoring system. In this system, each region is scored from 0 to 3, with higher scores indicating greater loss of lung aeration. Lung ultrasound examinations will be performed according to a predefined scanning protocol, and image interpretation will be conducted by an assessor blinded to group allocation.

  Immediately prior to tracheal extubation under general anesthesia at the completion of surgery.

Secondary Outcomes (8)

• Peak Inspiratory Pressure

  Assessed 15 minutes after prone positioning, at approximately hourly intraoperative intervals, and immediately prior to tracheal extubation.

• Dynamic Lung Compliance

  Assessed 15 minutes after prone positioning, at approximately hourly intraoperative intervals, and immediately prior to tracheal extubation.

• Peripheral Oxygen Saturation

  Assessed 15 minutes after prone positioning, at approximately hourly intraoperative intervals, and immediately prior to tracheal extubation.

• Incidence of Oxygen Desaturation

  From induction of anesthesia until 30 minutes after arrival in the post-anesthesia care unit (PACU).

• Total Lung Ultrasound Aeration Score

  Assessed 15 minutes after prone positioning, immediately prior to tracheal extubation, and within 30 minutes after arrival in the post-anesthesia care unit (PACU).

Study Arms (2)

Periodic Alveolar Recruitment Maneuver Group

EXPERIMENTAL

Participants assigned to this arm will receive standardized general anesthesia and mechanical ventilation according to routine clinical practice. After prone positioning, all participants will undergo a baseline alveolar recruitment maneuver performed within established clinical safety limits. In this experimental arm, additional alveolar recruitment maneuvers will be applied approximately once per hour throughout the intraoperative period to help maintain lung aeration. A final recruitment maneuver will also be performed before extubation as part of standard anesthetic care. Apart from the timing of recruitment maneuvers, intraoperative anesthetic and ventilatory management will be conducted according to routine clinical practice and individualized based on patient requirements.

Procedure: Alveolar Recruitment Maneuver

Standard Alveolar Recruitment Maneuver Group

ACTIVE COMPARATOR

Participants assigned to this arm will receive standardized general anesthesia and mechanical ventilation according to routine clinical practice. After prone positioning, a baseline alveolar recruitment maneuver will be performed within established clinical safety limits. No additional recruitment maneuvers will be applied during the intraoperative period apart from a final recruitment maneuver performed before extubation as part of standard anesthetic care. Intraoperative anesthetic and ventilatory management will otherwise follow routine clinical practice and will be guided by patient safety considerations.

Procedure: Alveolar Recruitment Maneuver

Interventions

Alveolar Recruitment Maneuver PROCEDURE

Alveolar recruitment maneuvers will be performed under general anesthesia using standard mechanical ventilation techniques within routine clinical safety limits. After prone positioning, a baseline recruitment maneuver will be applied by stepwise increasing positive end-expiratory pressure (PEEP) from 8 cmH₂O to 10 cmH₂O and 15 cmH₂O while maintaining an upper airway pressure limit of ≤30 cmH₂O for approximately 10 seconds. Following the maneuver, mechanical ventilation will continue with a PEEP level of approximately 8 cmH₂O according to routine clinical practice. In the periodic recruitment group, additional recruitment maneuvers will be repeated approximately once per hour during the intraoperative period. In the standard recruitment group, no additional intraoperative maneuvers will be applied apart from a final recruitment maneuver performed before extubation as part of routine anesthetic care.

Also known as: Lung Recruitment Maneuver

Periodic Alveolar Recruitment Maneuver Group; Standard Alveolar Recruitment Maneuver Group

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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 2 hours
• American Society of Anesthesiologists (ASA) physical status I-II
• Ability to provide written informed consent

You may not qualify if:

• 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 surgical duration shorter than 2 hours
• Refusal or inability to provide informed consent

Sponsors & Collaborators

• Prof. Dr. Cemil Tascıoglu Education and Research Hospital Organization: lead

Study Sites (1)

Prof. Dr. Cemil Tascıoglu Education and Research Hospital Organization

Istanbul, Turkey (Türkiye)

RECRUITING

Related Publications (7)

• York J, Nugent K. Using lung ultrasound to guide PEEP determination in mechanically ventilated patients. Southwest Respir Crit Care Chron. 2023;11(47):10-20.

  BACKGROUND

• Lee JM, Lee SK, Kim KM, Kim YJ, Park EY. Comparison of volume-controlled ventilation mode and pressure-controlled ventilation with volume-guaranteed mode in the prone position during lumbar spine surgery. BMC Anesthesiol. 2019 Jul 27;19(1):133. doi: 10.1186/s12871-019-0806-7.

  PMID: 31351445 BACKGROUND

• Gunenc FS, Seyidova I, Ozbilgin S, Ur K, Hanci V. Comparison of pressure controlled, volume controlled, and volume guaranteed pressure controlled modes in prone position in patients operated for lumbar disc herniation: A randomized trial. Medicine (Baltimore). 2024 Feb 9;103(6):e37227. doi: 10.1097/MD.0000000000037227.

  PMID: 38335373 BACKGROUND

• Jang YE, Ji SH, Kim EH, Lee JH, Kim JT, Kim HS. Effect of regular alveolar recruitment on intraoperative atelectasis in paediatric patients ventilated in the prone position: a randomised controlled trial. Br J Anaesth. 2020 May;124(5):648-655. doi: 10.1016/j.bja.2020.01.022. Epub 2020 Mar 10.

  PMID: 32169254 BACKGROUND

• Acosta CM, Maidana GA, Jacovitti D, Belaunzaran A, Cereceda S, Rae E, Molina A, Gonorazky S, Bohm SH, Tusman G. Accuracy of transthoracic lung ultrasound for diagnosing anesthesia-induced atelectasis in children. Anesthesiology. 2014 Jun;120(6):1370-9. doi: 10.1097/ALN.0000000000000231.

  PMID: 24662376 BACKGROUND

• Guldner A, Kiss T, Serpa Neto A, Hemmes SN, Canet J, Spieth PM, Rocco PR, Schultz MJ, Pelosi P, Gama de Abreu M. Intraoperative protective mechanical ventilation for prevention of postoperative pulmonary complications: a comprehensive review of the role of tidal volume, positive end-expiratory pressure, and lung recruitment maneuvers. Anesthesiology. 2015 Sep;123(3):692-713. doi: 10.1097/ALN.0000000000000754.

  PMID: 26120769 BACKGROUND

• Hartland BL, Newell TJ, Damico N. Alveolar recruitment maneuvers under general anesthesia: a systematic review of the literature. Respir Care. 2015 Apr;60(4):609-20. doi: 10.4187/respcare.03488. Epub 2014 Nov 25.

  PMID: 25425708 BACKGROUND

MeSH Terms

Conditions

Pulmonary Atelectasis

Condition Hierarchy (Ancestors)

Lung Diseases; Respiratory Tract Diseases

Study Officials

• Serap KARACALAR, MD (Doctor of Medicine)

  Prof. Dr. Cemil Tascıoglu Education and Research Hospital Organization

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Serap KARACALAR, MD (Doctor of Medicine)

CONTACT

+90 532 395 93 03; skaracalar@yahoo.com

Serencan OZER, MD (Doctor of Medicine)

CONTACT

+90 506 423 96 68; serencanozalp@gmail.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Masking Details: Lung ultrasound examinations and outcome assessments will be performed by an investigator blinded to group allocation in order to minimize assessment bias. Due to the nature of the intervention, the anesthesiology team responsible for intraoperative management and recruitment maneuver application cannot be blinded. Participants will be under general anesthesia during the intervention period and therefore will not be aware of group assignment.
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor of Anesthesiology and Reanimation

Model Details: Participants will be randomized in a 1:1 ratio using a computer-generated block randomization scheme to one of two parallel groups. Following standardized general anesthesia induction and prone positioning, all participants will receive a baseline alveolar recruitment maneuver performed within routine clinical safety limits. In the intervention group, additional alveolar recruitment maneuvers will be applied approximately once per hour throughout the intraoperative period, whereas participants in the control group will receive no additional recruitment maneuvers beyond the baseline intervention until the standard pre-extubation maneuver performed in both groups. Participants will remain in their assigned group throughout the study without crossover. Lung ultrasound assessments will be performed by an investigator blinded to group allocation.

Study Record Dates

• First Submitted: December 25, 2025
• First Posted: January 8, 2026
• Study Start: April 1, 2026
• Primary Completion (Estimated): July 1, 2026
• Study Completion (Estimated): July 1, 2026
• Last Updated: April 8, 2026

Record last verified: 2026-04

Locations

TU (1)