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

Inner Mongolia Baogang Hospital

Status: Not yet enrolling

Conditions: Laparoscopic Surgery

Treatments: Other: Pressure-regulated volume-controlled ventilation (PRVC); Other: Pressure-controlled ventilation (PCV); Other: Trendelenburg position; Other: Reverse Trendelenburg position; Other: Conventional volume-controlled ventilation (C-VCV); Other: Variable tidal volume ventilation (V-VCV)

Study type: Interventional

Funder types: Other

Identifiers

NCT06805747

2024-MER-312

Details and patient eligibility

About

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.

Enrollment: 240 estimated patients

Sex: All

Volunteers: No Healthy Volunteers

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.

Trial design

Primary purpose: Other

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

---

240 participants in 8 patient groups

T-V-VCV Group

Experimental group

Description:

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.

Treatment:

Other: Variable tidal volume ventilation (V-VCV)

Other: Trendelenburg position

T-PRVC Group

Experimental group

Description:

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.

Treatment:

Other: Trendelenburg position

Other: Pressure-regulated volume-controlled ventilation (PRVC)

T-C-VCV Group

Experimental group

Description:

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.

Treatment:

Other: Conventional volume-controlled ventilation (C-VCV)

Other: Trendelenburg position

T-PVC Group

Experimental group

Description:

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.

Treatment:

Other: Trendelenburg position

Other: Pressure-controlled ventilation (PCV)

R-V-VCV Group

Experimental group

Description:

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.

Treatment:

Other: Variable tidal volume ventilation (V-VCV)

Other: Reverse Trendelenburg position

R-PRVC Group

Experimental group

Description:

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.

Treatment:

Other: Reverse Trendelenburg position

Other: Pressure-regulated volume-controlled ventilation (PRVC)

R-C-VCV Group

Experimental group

Description:

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.

Treatment:

Other: Conventional volume-controlled ventilation (C-VCV)

Other: Reverse Trendelenburg position

R-PVC Group

Experimental group

Description:

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.

Treatment:

Other: Reverse Trendelenburg position

Other: Pressure-controlled ventilation (PCV)