Surgical Positions and Postoperative Atelectasis: A Lung Ultrasound Study

NCT07654153 | Not Yet Recruiting

• 1 other identifier: 2025-11/01
• Study Type: observational
• Target: 100
• Locations: 1 country
• Sites: 1

Brief Summary

The aim of this study is to prospectively evaluate the effect of surgical position on the development of postoperative atelectasis in patients undergoing surgery in supine, prone, lateral decubitus, and lithotomy positions using lung ultrasonography (LUS), and to investigate whether there is a difference between these positions.

Conditions

Lung Ultrasound; Atelectasis

Keywords

lung ultrasound

Outcome Measures

Primary Outcomes (1)

• Modified Lung Ultrasound Score

  MLUS Scoring: Each region will be scored between 0-3 according to lung ventilation (MLUS Score): * 0 Points: Normal ventilation (presence of A-line, fewer than 3 B-lines) * 1 Point: Minor ventilation loss (≥ 3 B-lines or subpleural consolidations ≤ 1 cm in diameter separated by a normal pleural line) * 2 Points: Moderate ventilation loss (Multiple small subpleural consolidations ≤ 1 cm in diameter separated by multiple and converging B-lines or a thickened/irregular pleural line) * 3 Points: Severe ventilation loss (At least one consolidation \> 1 cm in diameter or subpleural consolidations \> 1x2 cm in diameter) The total MLUS score will be obtained by summing the scores of the 12 regions (Minimum 0, Maximum 36). Atelectasis will be defined as "predisposition to atelectasis when each quadrant score is 2 or 3".

  The assessment will be performed at 3 different time points: 1. Preoperative (T0): Immediately before anesthesia induction, in the supine position (Baseline). 2. Postoperative 1st hour (T1): Immediately before the patient is awakened, in the supine posit

Study Arms (4)

Group 1

Supine position

Procedure: lung ultrasound

group 2

prone position

Procedure: lung ultrasound

group 3

lateral decubitus

Procedure: lung ultrasound

Group 4

lithotomy

Procedure: lung ultrasound

Interventions

lung ultrasound PROCEDURE

Lung Ultrasound (LUS) Protocol: The LUS evaluation will be performed by Dr. Burak Ağar using a Mindray ultrasound device \[Device brand/model and probe type, e.g., 3.5-5 MHz convex or 7-12 MHz linear probe\]

Group 1; Group 4; group 2; group 3

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Probability Sample

Study Population

The study will include a total of 100 patients in 4 groups, aged 18-65 years, with an ASA (American Society of Anesthesiologists) physical status between I and III, who are scheduled to undergo general anesthesia in supine, prone, lateral decubitus, and lithotomy positions.

You may qualify if:

• Being between 18-65 years of age
• Having ASA I-III status
• Planning elective surgery under general anesthesia
• Agreeing to participate in the study and signing the consent form

You may not qualify if:

• Patients requiring emergency surgery
• Patients with ASA IV or higher
• Presence of a known serious preoperative lung disease (COPD, Asthma, Pneumonia, Pleural effusion, Pneumothorax, Interstitial lung disease, Bronchiectasis, etc.)
• History of neuromuscular disease
• Body Mass Index (BMI) \> 35 kg/m² (Morbid obesity)
• Presence of chest wall deformity or skin lesions that would obstruct LUS imaging
• Cases with surgery duration \< 90 minutes
• Patients with alcohol or drug dependence
• Patients with significant anemia
• Pregnant and lactating patients
• Patients experiencing laryngospasm after extubation
• Refusal to give consent or inability to cooperate

Sponsors & Collaborators

• Cumhuriyet University: lead

Study Sites (1)

Sivas Cumhuriyet University

Sivas, Sivas, 58140, Turkey (Türkiye)

Location

MeSH Terms

Conditions

Pulmonary Atelectasis

Condition Hierarchy (Ancestors)

Lung Diseases; Respiratory Tract Diseases

Study Design

• Study Type: observational
• Observational Model: CASE ONLY
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor

Study Record Dates

• First Submitted: June 12, 2026
• First Posted: June 17, 2026
• Study Start (Estimated): July 20, 2026
• Primary Completion (Estimated): June 20, 2027
• Study Completion (Estimated): August 1, 2027
• Last Updated: June 17, 2026

Record last verified: 2026-06

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)