Positional Effects on Lung Ventilation and Perfusion in Obesity

NCT07341113 | Completed

• 1 other identifier: 2025.510.IRB2.232
• Study Type: observational
• Target: 40
• Locations: 1 country
• Sites: 1

Brief Summary

Electrical Impedance Tomography (EIT) is a non-invasive, bedside monitoring tool that provides real-time information on regional ventilation and perfusion. In particular, EIT has the potential to guide individualized mechanical ventilation in obese patients by revealing how gravitational and positional factors alter regional lung behavior. Assessing the effects of different horizontal positions on both ventilation and perfusion may help optimize respiratory management strategies tailored to body habitus. By comparing obese and non-obese healthy participants across different positions, this study aims to provide novel insights into the postural effects on lung aeration and perfusion distribution, and to highlight the role of EIT in tailoring individualized ventilation strategies.

Conditions

Obesity (Disorder); Ventilation Homogeneity; Perfusion; Ventilation Perfusion Mismatch; Position Differences; Electrical Impedance Tomography (EIT)

Keywords

obesity; ventilation perfusion; electrical impedance tomography; body positions

Outcome Measures

Primary Outcomes (1)

• MI

  Match Index (MI, 0-100%): quantifying the spatial overlap of ventilation and perfusion distributions. MI values will be taken from the device's Match View. Change in Match Index (MI) between obese and non-obese participants across positions will be compared.

  Periprocedural

Secondary Outcomes (11)

• VV %

  Periprocedural

• DV %

  Periprocedural

• VP %

  Periprocedural

• DP %

  Periprocedural

• DI %

  Periprocedural

Study Arms (2)

Non-obese group

Non-obese healthy individuals with BMI between 18.5 - 25 kg/m²

Other: Standardized body positioning

Obese group

Obese healthy individuals with BMI between 30 - 40 kg/m²

Other: Standardized body positioning

Interventions

Standardized body positioning OTHER

Standardized changes in body position (supine, Trendelenburg, prone, and lateral positions) performed solely for physiologic assessment of ventilation and perfusion using electrical impedance tomography. This does not constitute a therapeutic or preventive intervention.

Non-obese group; Obese group

Eligibility Criteria

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

Study Population

Healthy non-obese and obese volunteers

You may qualify if:

• BMI between 18-25 kg/m² or 30-40 kg/m²

You may not qualify if:

• Individuals with a body mass index (BMI) between 25 and 30 kg/m²,
• Pregnancy
• Respiratory tract infection within the previous two weeks
• Anatomical abnormalities of the chest wall that may interfere with Electrical Impedance Tomography (EIT) measurements.

Sponsors & Collaborators

• Koç University: lead

Study Sites (1)

Koç University Hospital

Istanbul, 34010, Turkey (Türkiye)

Location

Related Publications (1)

• De Jong A, Wrigge H, Hedenstierna G, Gattinoni L, Chiumello D, Frat JP, Ball L, Schetz M, Pickkers P, Jaber S. How to ventilate obese patients in the ICU. Intensive Care Med. 2020 Dec;46(12):2423-2435. doi: 10.1007/s00134-020-06286-x. Epub 2020 Oct 23.

  PMID: 33095284 BACKGROUND

MeSH Terms

Conditions

Obesity

Condition Hierarchy (Ancestors)

Overweight; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Evren Şentürk, MD

  Koç University School of Medicine

  STUDY DIRECTOR

Study Design

• Study Type: observational
• Observational Model: CASE CROSSOVER
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: December 15, 2025
• First Posted: January 14, 2026
• Study Start: December 1, 2025
• Primary Completion: March 5, 2026
• Study Completion: March 5, 2026
• Last Updated: April 15, 2026

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF, CSR
• Time Frame: 6 months after the publication
• Access Criteria: Academic purposes

Locations

TU (1)