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

Nigde Omer Halisdemir University

Status: Enrolling

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

Treatments: Procedure: Positive End-Expiratory Pressure (PEEP)

Study type: Interventional

Funder types: Other

Identifiers

NCT06979999

2024/54 (Other Identifier)

Details and patient eligibility

About

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.

Enrollment: 50 estimated patients

Sex: All

Ages: 18 to 70 years old

Volunteers: No Healthy Volunteers

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

Trial design

Primary purpose: Diagnostic

Allocation: N/A

Interventional model: Single Group Assignment

Masking: None (Open label)

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50 participants in 1 patient group

PEEP Group

Experimental group

Description:

This arm includes patients undergoing laparoscopic cholecystectomy under general anesthesia. All participants receive 10 cmH₂O PEEP after pneumoperitoneum creation, and optic nerve sheath diameter (ONSD) is measured intraoperatively at predefined time points.

Treatment:

Procedure: Positive End-Expiratory Pressure (PEEP)