Optimization of PEEP During Laparoscopic Surgery

Study Overview
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Brief Summary
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Lung-protective ventilation (LPV) during general anesthesia can trigger the development of early postoperative pulmonary complication (PPC) and ventilator associated lung injury. One of the proven components of the LPV is low tidal volume (TV). Data on the positive end-expiratory pressure (PEEP) parameters adjustment in laparoscopic surgery, as well as the effects on the respiratory biomechanics, lung tissue and respiratory muscles damage are limited and not clear. The objective of the study is to evaluate the ability of the esophageal pressure (Pes) based controlled personalized PEEP adjustment, to improve the biomechanics of the respiratory system and oxygenation due to laparoscopic cholecystectomy.

Detailed Description
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During laparoscopic surgery pressure on alveoli increases, due to in the conditions of pneumoperitoneum, muscle relaxation, the patient's position on the operating table, excess body weight and other factors. As the consequence, the alveoli collapse due to negative transpulmonary pressure. The personalized PEEP adjustment for each particular patient during laparoscopic surgery can help to avoid the adverse effects on biomechanical parameters of the respiratory system, the early PPC incidence and improve overall patients' recovery. The objective of the study is to evaluate the ability of the esophageal pressure (Pes) based controlled personalized PEEP adjustment, to improve the biomechanics of the respiratory system and oxygenation due to laparoscopic cholecystectomy. Investigators will measure if PEEP adjustment according to the pressure indicators in the lower third of the esophagus Pes (intervention group) versus PEEP constantly set at 5 cmH2O (control group) gives better outcomes and prevent the early PPC incidence in hospitals. After the induction, intubation and insertion of the esophageal balloon catheter, TV for patients both groups is set to 6 ml / kg BMI: for men (50+0.91* (height-152.4), for women (45+0.91* (height-152.4); minute ventilation (MV) to ensure the level of PetCO2 - 30-35 mmHg, respiratory rate (RR) 15-25/min (maximum up to 35/min). Gas exchange parameters including partial pressures of oxygen (PaO2) and carbon dioxide (PaCO2) in arterial blood will be measured before the induction (T0), after 1 hour after surgery (T5) and after 24 hours after surgery (T6), then will calculate PAO2/FiO2 respectively. FiO2, oxygen saturation (SpO2), hemodynamic parameters including blood pressure (BP), heart rate (HR) will be recorded in all point of the study. Following respiratory mechanics will be measured: plateau pressure (Pplat), PEEP, driving pressure (DP), Pes during inspiration and expiration, volumetric capnometry (VCO2), end-tidal carbon dioxide tension (PetCO2). Respiratory system compliance (Cstat, Cl, Ccw), end-expiratory lung volume (EELV) will calculated after intubation (T1), after PEEP set according to the patient's group allocation PEEP Pes and PEEP 5 (T2), after initiating pneumoperitoneum (T3) and placing the patient in the reverse Trendelenburg position (T4). This is a randomized controlled study in the operating room of the University hospitals.

Official Title
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Optimization of Positive End-expiratory Pressure During Laparoscopic Surgery

Conditions
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Post-Op Complication, Ventilator-Induced Lung Injury

Intervention / Treatment
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* Diagnostic Test: Respiratory monitoring
* Diagnostic Test: Capnography
* Diagnostic Test: Arterial blood gas
* Device: Esophageal pressure


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients undergoing laparoscopic surgery with mechanical lung ventilation American Society of Anesthesiologists Classification (ASA) I-III Exclusion Criteria: pregnancy age less than 18 or more than 70 years patients ASA > III life-threatening heart rhythm abnormalities and/or systolic blood pressure < 80 mmHg despite norepinephrine at a dose > 2 μg/kg/min primary lung diseases (e.g. interstitial lung diseases, lung emphysema) or tumor metastases in the lungs chronic decompensated diseases with extrapulmonary organ dysfunction (tumor progression, liver cirrhosis, congestive heart failure) Glasgow coma score < 14 upper airways obstruction

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: PEEP Pes<br>PEEP adjustment according to the pressure indicators in the lower third of the esophagus Pes (intervention group) | Diagnostic Test: Respiratory monitoring<br>* Measurement of the plateau pressure, positive end-expiratory pressure, driving pressure, end-expiratory lung volume, compliance of respiratory system on volume-controlled ventilation<br>Diagnostic Test: Capnography<br>* Measurement of end-tidal carbon dioxide tension, volume of CO2 eliminated per minute<br>Diagnostic Test: Arterial blood gas<br>* Measurement of the oxygen partial pressure and the carbon dioxide partial pressure<br>Device: Esophageal pressure<br>* Measurement the pressure in the lower third of esophagus during inspiration and expiration<br>|
| Active Comparator: PEEP 5<br>PEEP constantly set at 5 cmH2O (control group) | Diagnostic Test: Respiratory monitoring<br>* Measurement of the plateau pressure, positive end-expiratory pressure, driving pressure, end-expiratory lung volume, compliance of respiratory system on volume-controlled ventilation<br>Diagnostic Test: Capnography<br>* Measurement of end-tidal carbon dioxide tension, volume of CO2 eliminated per minute<br>Diagnostic Test: Arterial blood gas<br>* Measurement of the oxygen partial pressure and the carbon dioxide partial pressure<br>Device: Esophageal pressure<br>* Measurement the pressure in the lower third of esophagus during inspiration and expiration<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in arterial partial oxygen tension to inspiratory oxygen fraction (PaO2/FiO2) ratio | Calculation of the arterial partial oxygen tension to inspiratory oxygen fraction (PaO2/FiO2) ratio using arterial oxygen tension measurement and compare between groups | 5 minutes before intubation,1 hour after surgery, 24 hour after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Dynamics of the end-expiratory lung volume | Calculation the end-expiratory lung volume (ml) and compare with expected and between groups | 5 minutes after induction and intubation, 5 minutes after PEEP setting, 5 minutes after pneumoperitoneum, 5 minutes after reverse Trendelenburg position | 
| Dynamics of the respiratory biomechanics | Calculation the compliance of respiratory system (ml/mbar) and compare between groups at all time points | 5 minutes after induction and intubation, 5 minutes after PEEP setting, 5 minutes after pneumoperitoneum, 5 minutes after reverse Trendelenburg position | 
| Dynamics of the volume of CO2 eliminated per minute | Measurement of volume of CO2 eliminated per minute (VCO2 in ml/min), than compare the trends as a marker of lung ventilation | 5 minutes after induction and intubation, 5 minutes after PEEP setting, 5 minutes after pneumoperitoneum, 5 minutes after reverse Trendelenburg position | 
| Dynamics of the partial pressure of CO2 in exhaled gas | Measurement of partial pressure of CO2 in exhaled gas (PetCO2 in mmHg) than compare the trends as a marker of lung ventilation | 5 minutes after induction and intubation, 5 minutes after PEEP setting, 5 minutes after pneumoperitoneum, 5 minutes after reverse Trendelenburg position | 
| Dynamics of the hemodynamic parameters | Measurement of the arterial blood pressure (mmHg) and compare between groups at all time points | 5 minutes after induction and intubation, 5 minutes after PEEP setting, 5 minutes after pneumoperitoneum, 5 minutes after reverse Trendelenburg position | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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positive end-expiratory pressure, esophageal pressure, laparoscopic surgery