Bariatric Electrical Impedance Tomography

Anesthesia Clinical Trial

Official title:

Evaluation of Atelectasis Formation and Regression With Electrical Impedance Tomography in the Perioperative Phase of Obese Patients Scheduled for Laparoscopic Bariatric Surgery

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT05187039
• Other study ID #: 2021-01473
• Status: Completed
• Start date: October 19, 2021
• Est. completion date: March 8, 2023

Study information

• Verified date: March 2023
• Source: University Hospital Inselspital, Berne
• Contact: n/a
• Is FDA regulated: No
• Study type: Observational

Clinical Trial 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.

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 30
• Est. completion date: March 8, 2023
• Est. primary completion date: November 1, 2022
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years and older

Eligibility

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

Related Conditions & MeSH terms

• Anesthesia

Intervention

Other:
• 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).

Locations

Country	Name	City	State
Switzerland	University Hospital Bern	Bern

Sponsors (1)

Lead Sponsor	Collaborator
University Hospital Inselspital, Berne

Country where clinical trial is conducted

Switzerland, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Proportion of poorly ventilated lung areas (silent spaces)	Proportion of poorly ventilated lung areas (silent spaces) by using electrical impedance tomography (EIT) before the discharge from PACU (two hours after admission to PACU).	2 hours
Secondary	EIT-Measurement after the end of induction before the surgical procedure	Detection of changes in silent spaces, ventilation inhomogeneity and end-expiratory lung impedance (EELI) by using electrical impedance tomography (EIT)	2 minutes after the end of anesthesia induction
Secondary	EIT-Measurement at the end of the surgical procedure	Detection of changes in silent spaces, ventilation inhomogeneity and end-expiratory lung impedance (EELI) by using electrical impedance tomography (EIT)	5 minutes after Capnoperitoneum
Secondary	EIT-Measurement 2 minutes after the end of anaesthesia, before the transport in PACU	Detection of changes in silent spaces, ventilation inhomogeneity and end-expiratory lung impedance (EELI) by using electrical impedance tomography (EIT)	2 minutes after the end of anaesthesia, before the transport to PACU.
Secondary	EIT-Measurement before discharge from the PACU	Detection of changes in silent spaces, ventilation inhomogeneity and end-expiratory lung impedance (EELI) by using electrical impedance tomography (EIT)	Two hours after admission of the patient at PACU, before first mobilisation and before discharge from PACU
Secondary	EIT-Measurement before discharging the patient at home	Detection of changes in silent spaces, ventilation inhomogeneity and end-expiratory lung impedance (EELI) by using electrical impedance tomography (EIT)	At hospital discharge, up to 3 days
Secondary	Duration of surgical procedure.	Duration of surgical procedure.	Up to 90 to 150 minutes
Secondary	Duration of anaesthesia	Duration of anaesthesia	Up to 90 to 180 minutes
Secondary	Desaturation below 90%.	Difference of formation and course of silent lung areas in patients with and without pre-existing CPAP-therapy	During anaesthesia monitoring, from 1 to 10 minutes
Secondary	Follow up at 14 days	Follow-up by phone, regarding respiratory complications or need for rehospitalization.	14 days