End-expiratory Pressure During Laparoscopic Surgery in the Trendelenburg Position by Electrical Impedance Tomography
NCT Number: NCT06481124
Acronym: CP-EIT
Status: NOT_YET_RECRUITING
Study Type: OBSERVATIONAL
Conditions: Pneumoperitoneum|Trendelenburg Position|Laparoscopic Surgery
Interventions: DEVICE: electrical impedance tomography
Sponsor: I.M. Sechenov First Moscow State Medical University
Sex: FEMALE
Age: ADULT, OLDER_ADULT
Enrollment: 30
Study Design: Observational Model: |Time Perspective: p
Start Date: 2024-06-24
Completion Date: 2024-12-31

Summary:
Pneumoperitoneum (PNP) and the position of the patient required for laparoscopic surgery lead to pathophysiological changes that complicate anesthesia. PNP is characterized by an increased intra-abdominal pressure (IAP), the cranial displacement of the diaphragm that can lead to the formation of intraoperative atelectasis and decrease end-expiratory lung volume (EELV). At the same time, PNP can reduce respiratory system compliance by 30-50% in healthy patients. During elective abdominal surgery under general anesthesia, atelectasis forms in almost 90% of patients and can become a focus of postoperative pneumonia. The negative effect of PNP is more prominent in Trendelenburg position. And one of the methods to avoid the effects of PNP and Trendelenburg position on lung tissue is to apply positive end-expiratory pressure (PEEP). PEEP is acknowledged as a component of lung protective ventilation (LPV) along with low tidal volume (TV) 6-8 ml/kg. On the other hand, excessive PEEP can lead to the overdistension of lung tissue and cause volutrauma and hemodynamic instability. It is necessary to use sufficient PEEP to minimize atelectasis, improve respiratory biomechanics and maintain oxygenation.

Electrical impedance tomography shows changes in ventilation and perfusion during mechanical ventilation with the different PEEP levels.

The study aimed to select optimum PEEP level based on optimum ventilation-to-perfusion match based on electrical impedance tomography measurements.

Primary Outcome Measures: Optimum positive end-expiratory pressure level by compliance win, Positive end-expiratory pressure level selected by maximal compliance win measured by electrical impedance tomography, 40 minutes|Optimum positive end-expiratory pressure level by heart-lung index, Positive end-expiratory pressure level selected by maximal heart-lung index measured by electrical impedance tomography, 40 minutes
Secondary Outcome Measures: Compliance win, Increase in compliance measured by electrical impedance tomography in percent, 3 minutes|Compliance loss, Decrease in compliance measured by electrical impedance tomography in percent, 3 minutes|Global inhomogeneity index, Global inhomogeneity index measured by electrical impedance tomography in percent, 3 minutes|Regional ventilation delay, Regional ventilation delay measured by electrical impedance tomography in percent, 3 minutes|Lung-heart index, Lung-heart index measured by electrical impedance tomography in percent, 3 minutes|Resistivity of Low Pass Band, Low pass band resistivity measured by electrical impedance tomography in Ohms\*m, 3 minutes|Resistivity of High Pass Band, High pass band resistivity measured by electrical impedance tomography in Ohms\*m, 3 minutes|End-expiratory volume index change, End-expiratory volume index change measured by electrical impedance tomography, 3 minutes|Plateau pressure, Pressure measured in circuit during the inspiratory pause in mbar, 3 minutes|Driving pressure, Difference between plateau pressure and positive end-expiratory pressure in mbar, 3 minutes