A Comparative Study of Ventilation Strategies in Different Surgical Positions on Intracranial Pressure and Cerebral Blood Flow During Laparoscopic Surgery

The purpose of this clinical trial is to investigate the effects of laparoscopic surgery in the Trendelenburg and Reverse Trendelenburg positions, and variable tidal volume ventilation (V-VCV), pressure-regulated volume-controlled ventilation (PRVC), conventional volume-controlled ventilation (C-VCV), and pressure-controlled ventilation (PCV) on esophageal pressure, airway pressure, tidal volume, intracranial pressure, and cerebral blood flow.

The study aims to address the following primary questions:Does laparoscopic surgery in the Trendelenburg or Reverse Trendelenburg position increase esophageal pressure, airway pressure, and intracranial pressure, and decrease tidal volume and cerebral blood flow? Do variable tidal volume ventilation (V-VCV), pressure-regulated volume-controlled ventilation (PRVC), conventional volume-controlled ventilation (C-VCV), or pressure-controlled ventilation (PCV) increase esophageal pressure, airway pressure, and intracranial pressure, and decrease tidal volume and cerebral blood flow? The investigators will compare variable tidal volume ventilation (V-VCV), pressure-regulated volume-controlled ventilation (PRVC), conventional volume-controlled ventilation (C-VCV), and pressure-controlled ventilation (PCV) to determine which ventilation mode results in the least physiological disturbance for patients.

Participant Procedures:

Participants will: Be positioned according to the surgical requirements.Be randomly assigned to mechanical ventilation with either variable tidal volume ventilation (V-VCV), pressure-regulated volume-controlled ventilation (PRVC), conventional volume-controlled ventilation (C-VCV), or pressure-controlled ventilation (PCV).

Undergo assessments at the following time points: immediately after endotracheal intubation, immediately after pneumoperitoneum, immediately after position change (Trendelenburg or Reverse Trendelenburg), 30 minutes after position change, and 1 hour after position change.

Have their esophageal pressure, airway pressure, intracranial pressure, tidal volume, and internal jugular vein blood flow recorded at each assessment time point.

Study Overview

• Status: Not yet recruiting
• Conditions: Laparoscopic Surgery
• Intervention / Treatment: Other: Variable tidal volume ventilation (V-VCV); Other: Trendelenburg position; Other: Pressure-regulated volume-controlled ventilation (PRVC); Other: Conventional volume-controlled ventilation (C-VCV); Other: Pressure-controlled ventilation (PCV); Other: Reverse Trendelenburg position

• Study Type: Interventional
• Enrollment (Estimated): 240
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Xiaguang XG Duan, Master's degree; Phone Number: +86 13314720012; Email: alonlord2023@gmail.com

Study Locations

• China
  • Inner Mongolia
    • Baotou, Inner Mongolia, China, 014010
      • Inner Mongolia Baogang Hospital
      • Contact: Xiangyu Wang XY Wang, Undergraduate; Phone Number: +86 0472 5992830; Email: KevinDuan0901@gmail.com
      • Contact: Xiaoyu Zhang

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age: Unrestricted
• American Society of Anesthesiologists (ASA) Physical Status: Class I-III
• Surgical Position: Requires the use of either the Trendelenburg position or the Reverse Trendelenburg position during the procedure.
• Ventilation: Planned mechanical ventilation is required during the procedure, with suitability for one of the following modes: pressure-regulated volume-controlled ventilation (PRVC), conventional volume-controlled ventilation (C-VCV), or pressure-controlled ventilation (PCV).

Exclusion Criteria:

• Significant Cardiopulmonary Disease:
• Intracranial Disease
• Severe Coagulopathy or Current Anticoagulant Therapy
• Presence of Psychiatric Illness, Cognitive Impairment, or other condition that precludes the ability to understand or comply with the study.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

8

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: T-V-VCV Group; Variable tidal volume ventilation (V-VCV) ：The initial tidal volume was set at 6-8 ml/kg IBW according to the Ideal Body Weight (IBW).The maximum tidal volume (Vt_max) and minimum tidal volume (Vt_min) were set at 10-20% of the basal tidal volume (Vt_base). Respiratory Rate 12. Inspiratory Flow Rate (IFR) 60L/min, Inspiratory to Expiratory Ratio (IER) 1:2, Positive End-Expiratory Pressure (PEEP) 5cm water column, and Inhaled Oxygen Concentration (FiO2) 41%. Use of the trendelenburg position：Lower the head of the bed by 30 degrees with no more than 15 degrees of lateral tilt.	Other: Variable tidal volume ventilation (V-VCV); Variable tidal volume ventilation (V-VCV) ：The initial tidal volume is set at 6-8 ml/kg IBW according to the Ideal Body Weight (IBW), and the maximum tidal volume (Vt_max) and minimum tidal volume (Vt_min) are set at 10-20% of the base tidal volume (Vt_base). Respiratory Rate 12. Inspiratory Flow Rate (IFR) 60L/min, Inspiration to Expiration Ratio (IER) 1:2, Positive End-Expiratory Pressure (PEEP) 5 cm water column, and Inhaled Oxygen Concentration (FiO2) 41%.; Other: Trendelenburg position; Trendelenburg position：Lower the head of the bed by 30 degrees with no more than 15 degrees of lateral tilt.
Experimental: T-PRVC Group; Pressure-regulated volume-controlled ventilation (PRVC) ：The initial tidal volume was set at 6-8 ml/kg IBW according to the Ideal Body Weight (IBW), the upper limit of peak inspiratory pressure was 30 cmH2O, the maximum tidal volume (Vt_max) and the minimum tidal volume (Vt_min) was set at 10-20% of the base tidal volume (Vt_base). Respiratory Rate is 12, Inspiration to Expiration Ratio is 1:2, Positive End-Expiratory Pressure (PEEP) is 5cmH2O, and Inhaled Oxygen Concentration (FiO2) is 98%. Use of the trendelenburg position：Lower the head of the bed by 30 degrees with no more than 15 degrees of lateral tilt.	Other: Trendelenburg position; Trendelenburg position：Lower the head of the bed by 30 degrees with no more than 15 degrees of lateral tilt.; Other: Pressure-regulated volume-controlled ventilation (PRVC); Pressure-regulated volume-controlled ventilation (PRVC) ：Initial tidal volume is set at 6-8 ml/kg IBW based on Ideal Body Weight (IBW), peak inspiratory pressure is capped at 30 cmH2O, maximum tidal volume (Vt_max), and minimum tidal volume (Vt_min) is set at 10-20% of basal tidal volume (Vt_base). Respiratory Rate (RR) 12, Inspiratory Breathing Ratio (IBR) 1:2, Positive End-Expiratory Pressure (PEEP) 5 cm water column, and Inhaled Oxygen Concentration (FiO2) 98%.
Experimental: T-C-VCV Group; Conventional volume-controlled ventilation (C-VCV)The initial tidal volume was set at 6-8 ml/kg IBW according to the Ideal Body Weight (IBW).The maximum tidal volume (Vt_max) and minimum tidal volume (Vt_min) were set at 10-20% of the basal tidal volume (Vt_base). Respiratory Rate 12.Inspiratory Flow Rate (IFR) 60L/min, Inspiratory to Expiratory Ratio (IER) 1:2, Positive End-Expiratory Pressure (PEEP) 5cm water column, and Inhaled Oxygen Concentration (FiO2) 98%. Use of the trendelenburg position：Lower the head of the bed by 30 degrees with no more than 15 degrees of lateral tilt.	Other: Trendelenburg position; Trendelenburg position：Lower the head of the bed by 30 degrees with no more than 15 degrees of lateral tilt.; Other: Conventional volume-controlled ventilation (C-VCV); Conventional volume-controlled ventilation (C-VCV) ：The initial tidal volume is set at 6-8 ml/kg IBW based on Ideal Body Weight (IBW), and the maximum tidal volume (Vt_max) and minimum tidal volume (Vt_min) are set at 10-20% of the basal tidal volume (Vt_base). Respiratory Rate 12. Inspiratory Flow Rate (IFR) 60L/min, Inspiration to Expiration Ratio (IER) 1:2, Positive End-Expiratory Pressure (PEEP) 5cm water column, FiO2 98%.
Experimental: T-PVC Group; Pressure-controlled ventilation (PCV)：The inspiratory pressure level is set, usually with an initial value of 20 cmH2O, a respiratory rate of 12, an inspiratory/expiratory ratio of 1:2, a positive end-expiratory pressure (PEEP) of 5 cm water column, and an inspired oxygen concentration (FiO2) of 98%. Use of the trendelenburg position：Lower the head of the bed by 30 degrees with no more than 15 degrees of lateral tilt.	Other: Trendelenburg position; Trendelenburg position：Lower the head of the bed by 30 degrees with no more than 15 degrees of lateral tilt.; Other: Pressure-controlled ventilation (PCV); Pressure-controlled ventilation (PCV)：Set inspiratory pressure level, usually 20 cmH2O initial value, Respiratory Rate 12, Inspiratory to Expiratory Ratio 1:2, Positive End-Expiratory Pressure (PEEP) 5 cm water column, Inhaled Oxygen Concentration (FiO2) 98%.
Experimental: R-V-VCV Group; Variable tidal volume ventilation (V-VCV) ：The initial tidal volume was set at 6-8 ml/kg IBW according to the Ideal Body Weight (IBW).The maximum tidal volume (Vt_max) and minimum tidal volume (Vt_min) were set at 10-20% of the basal tidal volume (Vt_base). Respiratory Rate 12. Inspiratory Flow Rate (IFR) 60L/min, Inspiratory to Expiratory Ratio (IER) 1:2, Positive End-Expiratory Pressure (PEEP) 5cm water column, and Inhaled Oxygen Concentration (FiO2) 41%. Use of the reverse trendelenburg position：Elevate the head of the bed by 30 degrees with no more than 15 degrees of lateral tilt.	Other: Variable tidal volume ventilation (V-VCV); Variable tidal volume ventilation (V-VCV) ：The initial tidal volume is set at 6-8 ml/kg IBW according to the Ideal Body Weight (IBW), and the maximum tidal volume (Vt_max) and minimum tidal volume (Vt_min) are set at 10-20% of the base tidal volume (Vt_base). Respiratory Rate 12. Inspiratory Flow Rate (IFR) 60L/min, Inspiration to Expiration Ratio (IER) 1:2, Positive End-Expiratory Pressure (PEEP) 5 cm water column, and Inhaled Oxygen Concentration (FiO2) 41%.; Other: Reverse Trendelenburg position; Reverse Trendelenburg position：Elevate the head of the bed by 30 degrees with no more than 15 degrees of lateral tilt.
Experimental: R-PRVC Group; Pressure-regulated volume-controlled ventilation (PRVC) ：The initial tidal volume was set at 6-8 ml/kg IBW according to the Ideal Body Weight (IBW), the upper limit of peak inspiratory pressure was 30 cmH2O, the maximum tidal volume (Vt_max) and the minimum tidal volume (Vt_min) was set at 10-20% of the base tidal volume (Vt_base). Respiratory Rate is 12, Inspiration to Expiration Ratio is 1:2, Positive End-Expiratory Pressure (PEEP) is 5cmH2O, and Inhaled Oxygen Concentration (FiO2) is 98%. Use of the reverse trendelenburg position：Elevate the head of the bed by 30 degrees with no more than 15 degrees of lateral tilt.	Other: Pressure-regulated volume-controlled ventilation (PRVC); Pressure-regulated volume-controlled ventilation (PRVC) ：Initial tidal volume is set at 6-8 ml/kg IBW based on Ideal Body Weight (IBW), peak inspiratory pressure is capped at 30 cmH2O, maximum tidal volume (Vt_max), and minimum tidal volume (Vt_min) is set at 10-20% of basal tidal volume (Vt_base). Respiratory Rate (RR) 12, Inspiratory Breathing Ratio (IBR) 1:2, Positive End-Expiratory Pressure (PEEP) 5 cm water column, and Inhaled Oxygen Concentration (FiO2) 98%.; Other: Reverse Trendelenburg position; Reverse Trendelenburg position：Elevate the head of the bed by 30 degrees with no more than 15 degrees of lateral tilt.
Experimental: R-C-VCV Group; Conventional volume-controlled ventilation (C-VCV)The initial tidal volume was set at 6-8 ml/kg IBW according to the Ideal Body Weight (IBW).The maximum tidal volume (Vt_max) and minimum tidal volume (Vt_min) were set at 10-20% of the basal tidal volume (Vt_base). Respiratory Rate 12.Inspiratory Flow Rate (IFR) 60L/min, Inspiratory to Expiratory Ratio (IER) 1:2, Positive End-Expiratory Pressure (PEEP) 5cm water column, and Inhaled Oxygen Concentration (FiO2) 98%. Use of the reverse trendelenburg position：Elevate the head of the bed by 30 degrees with no more than 15 degrees of lateral tilt.	Other: Conventional volume-controlled ventilation (C-VCV); Conventional volume-controlled ventilation (C-VCV) ：The initial tidal volume is set at 6-8 ml/kg IBW based on Ideal Body Weight (IBW), and the maximum tidal volume (Vt_max) and minimum tidal volume (Vt_min) are set at 10-20% of the basal tidal volume (Vt_base). Respiratory Rate 12. Inspiratory Flow Rate (IFR) 60L/min, Inspiration to Expiration Ratio (IER) 1:2, Positive End-Expiratory Pressure (PEEP) 5cm water column, FiO2 98%.; Other: Reverse Trendelenburg position; Reverse Trendelenburg position：Elevate the head of the bed by 30 degrees with no more than 15 degrees of lateral tilt.
Experimental: R-PVC Group; Pressure-controlled ventilation (PCV)：The inspiratory pressure level is set, usually with an initial value of 20 cmH2O, a respiratory rate of 12, an inspiratory/expiratory ratio of 1:2, a positive end-expiratory pressure (PEEP) of 5 cm water column, and an inspired oxygen concentration (FiO2) of 98%. Use of the reverse trendelenburg position：Elevate the head of the bed by 30 degrees with no more than 15 degrees of lateral tilt.	Other: Pressure-controlled ventilation (PCV); Pressure-controlled ventilation (PCV)：Set inspiratory pressure level, usually 20 cmH2O initial value, Respiratory Rate 12, Inspiratory to Expiratory Ratio 1:2, Positive End-Expiratory Pressure (PEEP) 5 cm water column, Inhaled Oxygen Concentration (FiO2) 98%.; Other: Reverse Trendelenburg position; Reverse Trendelenburg position：Elevate the head of the bed by 30 degrees with no more than 15 degrees of lateral tilt.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
esophageal pressure	immediately after tracheal intubation
airway pressure	immediately after tracheal intubation
intracranial pressure	immediately after pneumoperitoneum
tidal volume	immediately after tracheal intubation
carotid blood flow	half an hour after change of position

Collaborators and Investigators

• Sponsor: Inner Mongolia Baogang Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): February 1, 2025
• Primary Completion (Estimated): May 1, 2025
• Study Completion (Estimated): May 10, 2025

Study Registration Dates

• First Submitted: January 19, 2025
• First Submitted That Met QC Criteria: January 28, 2025
• First Posted (Actual): March 25, 2025

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: January 28, 2025
• Last Verified: January 1, 2025

More Information

Terms related to this study

• Other Study ID Numbers: 2024-MER-312

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Sharing Time Frame: January 2026-January 2036
• IPD Sharing Access Criteria: A proposal that describes planned analyses must be submitted or whether a data sharing agreement must be signed.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No