Effect of Optimized PEEP on Mechanical Ventilation During Robot Assisted Laparoscopic Prostatectomy

Study Overview
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Brief Summary
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Steep trendelenburg posture or pneumoperitoneum for surgery causes ventilation problems during surgery, so finding a way to overcome is a challenging task for anesthesiologists. In this study, for patients undergoing robot assisted laparoscopic prostatectomy under general anesthesia, anesthesia is going to perform by applying conventional positive end-expiratory pressure (PEEP 5cmH2O) or individually determined positive end-expiratory pressure values for each patient using electrical impedance tomography. We plan to compare intraoperative ventilation through arterial blood gas analysis to find out the way to improve intraoperative ventilation.

Official Title
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Application of Individualized Positive End-expiratory Pressure Using Electrical Impedance Tomography (EIT) in Patients Undergoing Robot Assisted Laparoscopic Prostatectomy : a Randomized Controlled Study

Conditions
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Prostate Cancer

Intervention / Treatment
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* Device: conventional PEEP
* Device: optimized PEEP


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 20 - 70 years of age who are scheduled for robotic assisted laparoscopic prostatectomy at the Department of Urology, Gangnam Severance Hospital, ASA-PS (American Society of Anesthesiology Body Rating) I-IlI, Patients with a BMI of 35 kg/m2 or less Exclusion Criteria: Patients with lung disease BMI >35kg/m2 Patients for whom positive end-tidal pressure cannot be applied (large bullae, severe cardiac disease) patient refusal

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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Male

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: Other
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: conventional PEEP<br>Apply of PEEP 5 | Device: conventional PEEP<br>* Maintain positive end expiratory pressure at 5 cmH2O throughout the surgery.<br>|
| Active Comparator: optimized PEEP<br>Apply of optimized PEEP derived using EIT (airtom®) | Device: optimized PEEP<br>* Immediately after induction of anesthesia, the patient remains unapplied to PEEP. After pneumoperitoneum + Trendelenburg posture, an appropriate PEEP value is derived using electrical impedance tomography (airtom®). And then derived value ( = optimized PEEP value) is applied until the end of the operation.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| PaO2/FiO2 | PaO2/FiO2 is the ratio of arterial oxygen partial pressure (PaO2) to oxygen fraction (FiO2), and is a commonly used indicator for evaluating pulmonary ventilation and diagnosing lung damage. Using this index, it is possible to determine whether oxygen obtained through the lungs is well delivered to the blood or not. It can be easily obtained by arterial blood gas analysis without complicated formulas or graphs. | end of surgery (before extubation) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| PaO2/FiO2 | partial pressure (PaO2) to oxygen fraction (FiO2), and is a commonly used indicator for evaluating pulmonary ventilation and diagnosing lung damage. Using this index, it is possible to determine whether oxygen obtained through the lungs is well delivered to the blood or not. It can be easily obtained by arterial blood gas analysis without complicated formulas or graphs. | 15 minutes after intubation, 1 hour after pnemoperitoneum | 
| ROI (region of interests) | region of interest using EIT | 15 minutes after intubation, 1 hour after pnemoperitoneum, end of surgery (before extubation) | 
| inhomogeneity index | inhomogeneity index : this index calculated from tidal EIT images representing the difference in impedance between the end of inspiration and the end of expiration. | 15 minutes after intubation, 1 hour after pnemoperitoneum, end of surgery (before extubation) | 
| total amount of fluid administered during surgery |  | end or surgery | 
| total dose of vasopressor administered during surgery |  | end of surgery | 
| length of hospitalization after surgery |  | 1 month after surgery |