Evaluation of Regional Lung Mechanics in Obese Patients Undergoing Laparoscopic Surgery (OBESE-EIT)

Università degli Studi di Ferrara

Status: Enrolling

Conditions: Mechanical Ventilation Pressure High; Obesity; Intraoperative Respiratory Injury

Treatments: Procedure: PEEP titration trial

Study type: Interventional

Funder types: Other

Identifiers

NCT05554536

OBESE-EIT

Details and patient eligibility

About

This study will evaluate what is the impact of laparoscopy and Trendelenburg position on lung regional ventilation distribution in obese patients, focusing on the differences between the different phases of surgery.

Full description

Electrical impedance tomography (EIT) is a non invasive monitoring technique that allows to evaluate the regional distribution of ventilation. EIT has been used in different contexts, such as acute respiratory failure or intraoperative ventilation settings. Obesity, by increasing intrabdominal pressure, may reduce functional residual capacity after anesthesia and therefore require a more aggressive intraoperative ventilatory setting. In addition, laparoscopy, by increasing the volume of the abdomen, further pushes the diaphragm and increase the probability of lung collapse.

The aim of the current study is to describe the effect of 1) anesthesia and of 2) laparoscopy and trendelenburg position on regional ventilation distribution. Moreover, the investigators will evaluate if the best ventilatory parameters set after anesthesia induction are confirmed also when the condition changes (i.e. during pneumoperitoneum and trendellenburg).

Finally, the investigators will explore if the different parameters which can be provided by EIT agree in suggesting the best level of positive-end expiratory pressure in both moments of surgery.

Enrollment: 30 estimated patients

Sex: All

Ages: 18 to 80 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• age 18-90 years
• Body mass index > 30 kg/m2
• Major surgery
• Predicted duration of surgery > 2 hours
• Predicted presence of invasive arterial pressure monitoring

Exclusion criteria

• emergency surgery
• Refuse to participate from patient
• presence of Implantable cardiac device or pacemaker
• thoracic wounds
• thoracic surgery

Trial design

Primary purpose: Diagnostic

Allocation: N/A

Interventional model: Single Group Assignment

Masking: None (Open label)

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30 participants in 1 patient group

Single arm intervention

Other group

Description:

All patients will undergo a PEEP titration trial in each surgery step (before pneumoperitoneum, during pneumoperitoneum, after pneumoperitoneum). The PEEP titration trial will be done in steps of 2 cmH2O, starting from clinical PEEP 16 cmH2O and ending to PEEP 6 cmH2O. Each PEEP level will be kept for 2 minutes. The PEEP titration trial will be stopped in case of haemodynamic instability or severe desaturation (Spo2 \< 92%). Each PEEP titration trial will be recorded using Electrical impedance tomography (EIT).

Treatment:

Procedure: PEEP titration trial