The Effects of Positive End-expiratory Pressure (PEEP) on Optic Nerve Sheath Diameter in Laparoscopic Cholecystectomy

Not Applicable

Recruiting

• Conditions: Positive End-expiratory Pressure (PEEP); Intracranial Pressure; Optic Nerve Sheath Diameter; Mechanical Ventilation

• Registration Number: NCT06979999
• Lead Sponsor: Nigde Omer Halisdemir University

Brief Summary

This prospective interventional study will evaluate the effects of applying positive end-expiratory pressure (PEEP) at 10 cmH₂O on optic nerve sheath diameter (ONSD) in patients undergoing elective laparoscopic cholecystectomy under general anesthesia. A total of approximately 80 adult patients (ASA physical status I-III) will be included following informed consent.

ONSD will be measured using a high-frequency linear ultrasound probe at three predefined intraoperative time points: (T0) 10 minutes after initiation of mechanical ventilation, (T1) 10 minutes after pneumoperitoneum creation, and (T2) 30 minutes after pneumoperitoneum creation. Dynamic lung compliance, peak airway pressure (Ppeak), end-tidal CO₂ (EtCO₂), heart rate, mean arterial pressure, and SpO₂ will also be recorded.

The aim is to assess whether the application of PEEP influences intracranial pressure indicators, particularly ONSD, during laparoscopic procedures. The study may provide valuable insights into the neurophysiological effects of intra-abdominal pressure and mechanical ventilation strategies in surgical patients.

Detailed Description

Not available

Study Timeline

• Study Start: 2024-04-29
• Study First Submitted: 2025-04-29
• Status Verified: 2025-05
• Study First Submitted QC: 2025-05-16
• Last Update Submitted: 2025-05-16
• Study First Posted: 2025-05-20
• Last Update Posted: 2025-05-20
• Primary Completion: 2025-05-29
• Study Completion: 2025-07-29

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 50

Inclusion Criteria

• Adult patients (age ≥ 18 years)

American Society of Anesthesiologists (ASA) physical status I-III

Scheduled for elective laparoscopic cholecystectomy under general anesthesia

Signed informed consent

Exclusion Criteria

• resence of acute or chronic eye disease

Uncontrolled hypertension

Asthma or known chronic pulmonary disease

Any neurological disorders

Body mass index (BMI) > 35 kg/m²

Use of medications known to affect intracranial pressure

Refusal to participate after signing informed consent

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Primary Outcome Measures

Name	Time	Method
Change in Optic Nerve Sheath Diameter (ONSD)	Intraoperative; T0, T1, T2	ONSD will be measured via ultrasound at 3 time points during surgery.

Secondary Outcome Measures

Name	Time	Method
Change in Peak Airway Pressure (Ppeak)	Intraoperative measurement at T0, T1, and T2	Peak airway pressure will be measured using the ventilator settings at three predefined intraoperative time points to evaluate respiratory mechanics during PEEP application.
Change in Dynamic Lung Compliance	Intraoperative measurement at T0, T1, and T2	Dynamic lung compliance will be calculated using the formula: Tidal Volume / (Ppeak - PEEP) and measured at three intraoperative time points.
Change in End-Tidal Carbon Dioxide (EtCO₂)	Intraoperative measurement at T0, T1, and T2	End-tidal CO₂ levels will be recorded intraoperatively to monitor changes in ventilation efficiency during surgery.
Changes in Heart Rate (HR) and Mean Arterial Pressure (MAP) Time Frame	Intraoperative measurement at T0, T1, and T2	Heart rate and mean arterial pressure will be recorded at predefined time points to assess hemodynamic stability during surgery.
Peripheral Oxygen Saturation (SpO₂)	Intraoperative continuous monitoring and recorded at T0, T1, and T2	Peripheral oxygen saturation will be monitored continuously and recorded at specified intraoperative time points.

Trial Locations

Locations (1)

Niğde Training and Research Hospital; 🇹🇷 Niğde, Turkey