Bariatric Electrical Impedance Tomography

NCT ID: NCT05187039

Last Updated: 2023-03-09

Basic Information

• Recruitment Status: COMPLETED
• Total Enrollment: 30 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2021-10-19
• Study Completion Date: 2023-03-08

Brief Summary

This study investigates under controlled conditions the variation of poorly ventilated lung units (silent spaces) in obese patients scheduled for laparoscopic bariatric surgery in the perioperative phase.

Detailed Description

Eligible patients with written informed consent, scheduled for laparoscopic bariatric surgery. As for standard of care no premedication will be given for bariatric patients. Patients will be monitored according the local standard.

Thoracic electrical impedance tomography measurements (each measurement will last 1 min) will be performed at the following time points: before induction of the anaesthesia; before the surgical procedure when the induction is terminated and recruitment manoeuvers have been performed; after the termination of the surgical procedure; before transport to the Post anaesthesia Care Unit (PACU); before the discharge from the PACU after 2 hours of monitoring. An additional thoracic electrical impedance tomography measurement (duration 1 min) will be performed before discharge at home. For this, resulting potential differences are measured, and impedance distribution sampled at 30 Hz will be calculated by an automated linearized Newton-Raphson reconstruction algorithm. Relative change in poorly ventilated lung regions (silent spaces) and end-expiratory lung impedance (EELI) and measures of ventilation inhomogeneity such as the global inhomogeneity index will be calculated.

Conditions

Anesthesia

Study Design

• Observational Model Type: COHORT
• Study Time Perspective: PROSPECTIVE

Interventions

Electrical impedance tomography during anesthesia

Thoracic electrical impedance tomography measurements ( min each) will be performed at the following time points: before induction of the anaesthesia; before the surgical procedure when the induction is terminated and recruitment manoeuvers have been performed; after the termination of the surgical procedure; before transport to the Post anaesthesia Care Unit (PACU); before the discharge from the PACU after 2 hours of monitoring. An additional thoracic EIT-measurement will be performed before discharge at home. For this, resulting potential differences are measured, and impedance distribution sampled at 30 Hz will be calculated. Relative change in poorly ventilated lung regions (silent spaces) and end-expiratory lung impedance (EELI) and measures of ventilation inhomogeneity will be calculated using customised code (Matlab R2021a, The MathWorks, Nattick, Massachusetts, USA).

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• BMI >40
• ASA physical status 1 to 4
• Over 18 years of age providing written informed consent

Exclusion Criteria

• BMI <40
• Known severe pulmonary hypertension,
• Need of home oxygen therapy
• Known heart failure
• Suspected, or known recent pulmonal infections

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

Sponsors

Insel Gruppe AG, University Hospital Bern

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Matthias Braun, MD

Role: PRINCIPAL_INVESTIGATOR

University of Bern

Locations

University Hospital Bern

Bern, , Switzerland

Countries

Switzerland

Other Identifiers

2021-01473

Identifier Type: -

Identifier Source: org_study_id