Clinical trial NCT06979999: The Effects of Positive End-expiratory Pressure (PEEP) on Optic Nerve Sheath Diameter in Laparoscopic Cholecystectomy
Official title: The Effects of Positive End-Expiratory Pressure (PEEP) on Optic Nerve Sheath Diameter (ONSD) in Patients Undergoing Laparoscopic Cholecystectomy Under General Anesthesia: A Prospective Interventional Study
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: NA
Conditions: Positive End-expiratory Pressure (PEEP)
Intracranial Pressure
Optic Nerve Sheath Diameter
Mechanical Ventilation
Lead sponsor: Nigde Omer Halisdemir University
Sponsor class: OTHER
First posted: 2025-05-20
Enrollment: 50
Sex: ALL
Minimum age (years): 18
Maximum age (years): 70
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: DIAGNOSTIC

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.


Eligibility criteria: 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

Primary outcomes:
measure: Change in Optic Nerve Sheath Diameter (ONSD)
timeFrame: Intraoperative; T0, T1, T2
Secondary outcomes:
measure: Change in Peak Airway Pressure (Ppeak)
timeFrame: Intraoperative measurement at T0, T1, and T2
measure: Change in Dynamic Lung Compliance
timeFrame: Intraoperative measurement at T0, T1, and T2
measure: Change in End-Tidal Carbon Dioxide (EtCO₂)
timeFrame: Intraoperative measurement at T0, T1, and T2
measure: Changes in Heart Rate (HR) and Mean Arterial Pressure (MAP) Time Frame
timeFrame: Intraoperative measurement at T0, T1, and T2
measure: Peripheral Oxygen Saturation (SpO₂)
timeFrame: Intraoperative continuous monitoring and recorded at T0, T1, and T2
Other outcomes:
Locations:
city: Niğde
country: Turkey
facility: Niğde Training and Research Hospital
Study officials:
References: