An observational study in Lung Ultrasound and Atelectasis, sponsored by Cumhuriyet University. Not yet recruiting at 1 site in Turkey (Türkiye). Open to participants aged 18 Years to 80 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-07-21.
Sponsored by Cumhuriyet University · Observational
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.
Study Groups: Patients will be divided into 4 groups according to the surgical position to be given during the operation:
Lung Ultrasonography (LUS) Protocol: LUS evaluation, Dr. The ultrasound will be performed by 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]. LUS will be performed using a 12-zone protocol consisting of 6 standard zones (upper and lower quadrants of the anterior, lateral, and posterior regions) for both hemithoraxes. The evaluation will be performed at 3 different time points:
Postoperative (T2): 20 minutes after the patient is transferred to the PACU. MLUS Scoring: Each region will be scored between 0-3 according to lung ventilation (MLUS Score):
377 studies on the registry are indexed under Pulmonary Atelectasis; 93 are open to participants now.
This study's planned enrollment of 100 is above the median of 76 across 100 observational studies indexed under Pulmonary Atelectasis.
Browse Pulmonary Atelectasis studies →Cumhuriyet University is the lead sponsor of 133 studies on the registry; 26 are open to participants now.
Counted across the registry records on this site, refreshed daily.
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.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
ASA physical status
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
COPD
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Supine position
Procedure: lung ultrasound
prone position
Procedure: lung ultrasound
lateral decubitus
Procedure: lung ultrasound
lithotomy
Procedure: lung ultrasound
Lung Ultrasound (LUS) Protocol: The LUS evaluation will be performed by Dr. Burak Ağar using a Mindray ultrasound device \[Device brand/model and probe type, e.g., 3.5-5 MHz convex or 7-12 MHz linear probe\]
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"
Time frame: 1. (T0):Immediately before anesthesia induction, in the supine position 2.(T1): Immediately before the patient is awakened, in the supine posit 3.(T2):Twenty minutes after the patient was admitted to the PACU (Post-Anesthesia Care Unit)
Plan to share: No
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