Intraocular Pressure, Optic Nerve Sheath Diameter and Optic Perfusion Pressure of Minimal Low and High-Flow Anesthesia

NCT06684704 | Completed

• 1 other identifier: FSCH-SB-2024/09-46
• Study Type: interventional
• Target: 60
• Locations: 1 country
• Sites: 1

Brief Summary

The aim of this clinical trial is to determine the effect of minimal low-flow versus high-flow anesthesia on intraocular pressure (IOP) by non-contact tonometry, optic nerve sheath diameter (ONSD) by USG and optic perfusion pressure (OPP) in percutaneous nephrolithotomy operations. He will also learn about the effect on hemodynamic responses and arterial oxygenation. The main questions it aims to answer are: What are the effects of low-flow anesthesia combined with prone position on intraocular pressure (IOP), optic nerve sheath diameter (ONSD) and optic perfusion pressure (OPP)? Which anesthesia flow type has optimal eye-protective results? The investigators will compare minimal low-flow and high-flow anesthesia. Participants: The study will include patients between the ages of 18-60 years with ASA (American Society of Anesthesiologists) risk classification I-II-III, who are scheduled for unilateral percutaneous nephrolithotomy (PCNL) operation in the Urology Clinic under elective conditions and who have given informed consent.

Conditions

Anesthesia; Intraocular Pressure; Nephrolithiasis

Keywords

Minimal Low-Flow Anesthesia; Percutaneous Nephrolithotomy; Optic Nerve Sheath Diameter; non-contact tonometry

Outcome Measures

Primary Outcomes (1)

• Optic nerve sheath diameter (ONSD) measurements

  ONSD measurement bedside ultrasonography (POCUS) will be performed in accordance with the standardized ONSD POCUS Quality Criteria Checklist (ONSD POCUS QCC)

  Measurements will be performed serially after induction of anesthesia (T0), 1 min after intubation (T1), 30 min after supine position (T2), supine from prone position (T3) and 5 min after extubation (T4).

Secondary Outcomes (1)

• Intraocular pressure (IOP)

  Measurements will be performed serially after induction of anesthesia (T0), 1 min after intubation (T1), 30 min after supine position (T2), supine from prone position (T3) and 5 min after extubation (T4).

Study Arms (2)

Minimal Low-Flo Anesthesia

OTHER

Group M minimal flow (n=30, fresh gas flow 0.5 L/min)

Other: minimal and high flow anesthesia

High-Flow Anesthesia

OTHER

Group Y high flow (n=30, fresh gas flow 4 L/min).

Other: minimal and high flow anesthesia

Interventions

minimal and high flow anesthesia OTHER

Low-flow anesthesia technique is a technique based on the re-breathing of at least half of the gas exhaled in semi-closed systems by returning at least half of the exhaled gas to the patient in the next inspiration.

High-Flow Anesthesia; Minimal Low-Flo Anesthesia

Eligibility Criteria

• Age: 18 Years - 60 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Patients aged 18-60 years
• ASA (American Society of Anesthesiologists) risk classification I-II-III
• Unilateral percutaneous nephrolithotomy (PCNL) operation

You may not qualify if:

• Patients with drug and alcohol addiction,
• long-term smoking history (at least 1 pack/1 year),
• BMI\>35,
• chronic lung disease,
• cerebrovascular disease,
• severe systemic diseases such as kidney, liver or advanced heart failure .

Sponsors & Collaborators

• Elazıg Fethi Sekin Sehir Hastanesi: lead

Study Sites (1)

Elazığ Fethi Sekin City Hospital

Elâzığ, Seçiniz, 23100, Turkey (Türkiye)

Location

Related Publications (2)

• Jang YE, Nam S, Ji SH, Kim EH, Lee JH, Jung JH, Kim HS, Kim JT. Effect of end-tidal carbon dioxide level on the optic nerve sheath diameter measured by transorbital ultrasonography in anesthetized pediatric patients: A randomized trial. Paediatr Anaesth. 2022 Jun;32(6):754-763. doi: 10.1111/pan.14437. Epub 2022 Mar 20.

  PMID: 35279906 BACKGROUND

• Mermer A, Kozanhan B. Comparison of the effects of low-flow and normal-flow anesthesia on intracranial pressure, cerebral oxygenation and bispectral index in laparoscopic cholecystectomy operation. Eur Rev Med Pharmacol Sci. 2023 Sep;27(18):8514-8522. doi: 10.26355/eurrev_202309_33776.

  PMID: 37782167 BACKGROUND

MeSH Terms

Conditions

Nephrolithiasis

Condition Hierarchy (Ancestors)

Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Urolithiasis; Male Urogenital Diseases

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Masking Details: Both participants and investigators were blinded to the treatment assignments. The study utilized identical appearing interventions to maintain blinding.
• Purpose: SCREENING
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: November 9, 2024
• First Posted: November 12, 2024
• Study Start: September 15, 2024
• Primary Completion: June 15, 2025
• Study Completion: August 20, 2025
• Last Updated: September 5, 2025

Record last verified: 2025-07

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)