Clinical trial NCT05187039: Bariatric Electrical Impedance Tomography
Official title: Evaluation of Atelectasis Formation and Regression With Electrical Impedance Tomography in the Perioperative Phase of Obese Patients Scheduled for Laparoscopic Bariatric Surgery
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Anesthesia
Keywords: Bariatric
Obese
Laparoscopic
Electrical impedance tomography
Lead sponsor: Insel Gruppe AG, University Hospital Bern
Sponsor class: OTHER
First posted: 2022-01-11
Enrollment: 30
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: PROBABILITY_SAMPLE
Study population: The investigators will include obese patients exceeding body mass index (BMI) 40, scheduled for laparoscopic bariatric surgery at the University Hospital - Inselspital in Bern

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.

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

Primary outcomes:
measure: Proportion of poorly ventilated lung areas (silent spaces)
timeFrame: 2 hours
Secondary outcomes:
measure: EIT-Measurement after the end of induction before the surgical procedure
timeFrame: 2 minutes after the end of anesthesia induction
measure: EIT-Measurement at the end of the surgical procedure
timeFrame: 5 minutes after Capnoperitoneum
measure: EIT-Measurement 2 minutes after the end of anaesthesia, before the transport in PACU
timeFrame: 2 minutes after the end of anaesthesia, before the transport to PACU.
measure: EIT-Measurement before discharge from the PACU
timeFrame: Two hours after admission of the patient at PACU, before first mobilisation and before discharge from PACU
measure: EIT-Measurement before discharging the patient at home
timeFrame: At hospital discharge, up to 3 days
measure: Duration of surgical procedure.
timeFrame: Up to 90 to 150 minutes
measure: Duration of anaesthesia
timeFrame: Up to 90 to 180 minutes
measure: Desaturation below 90%.
timeFrame: During anaesthesia monitoring, from 1 to 10 minutes
measure: Follow up at 14 days
timeFrame: 14 days
Other outcomes:
Locations:
city: Bern
country: Switzerland
facility: University Hospital Bern
Study officials:
affiliation: University of Bern
name: Matthias Braun, MD
role: PRINCIPAL_INVESTIGATOR
References: