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

Summary

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.

Conditions

• Laparoscopic Surgery

Interventions

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

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

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

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

Trendelenburg position

Trendelenburg position：Lower the head of the bed by 30 degrees with no more than 15 degrees of lateral tilt.

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.

Sponsors & Collaborators

• Inner Mongolia Baogang Hospital

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

OTHER

Masking

SINGLE

Model

PARALLEL

Eligibility

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2025-02-01

Primary Completion

2025-05-01

Completion

2025-05-10

Countries

• China

Study Locations