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Lumbar Disc HerniationPROPEEPNCT07545733

Comparison of 5 vs 8 cmH₂O PEEP on Respiratory Mechanics in Prone Lumbar Surgery

A study testing Mechanical Ventilation (PEEP) in people with Lumbar Disc Herniation and Spinal Surgery, run by Harran University.

Not yet recruiting

Opening soon. The study is approved but enrolment has not started yet. Sites may already take enquiries.

Sites and contacts
Official record

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Trial summary

This randomized controlled clinical trial aims to compare the effects of two different positive end-expiratory pressure (PEEP) levels (5 cmH₂O and 8 cmH₂O) on respiratory mechanics in patients undergoing lumbar spine surgery in the prone position under total intravenous anesthesia (TIVA). Read more about this study

Who is it for?
Ages 18 to 65 years
What is being tested?
Mechanical Ventilation (PEEP)
Could I receive a placebo?
No, everyone receives an active treatment
How many people
60 participants
Where
No sites listed yet
Study dates
15 Aug 2026to 3 Oct 2026
Phase
Interventional

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 65 years
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Patients aged between 18 and 65 years
  • American Society of Anesthesiologists (ASA) physical status I-II
  • Scheduled for elective lumbar spine surgery in the prone position
  • Planned general anesthesia with total intravenous anesthesia (TIVA)
  • Ability to provide informed consent

Who cannot join

  • Body mass index (BMI) ≥ 30 kg/m²
  • History of significant pulmonary disease (e.g., COPD, asthma)
  • Severe cardiovascular disease
  • Pregnancy
  • Known difficult airway
  • Requirement for intraoperative vasopressor infusion due to hemodynamic instability
  • Conversion to different surgical position or change in surgical plan
  • Incomplete data or protocol deviation

Trial locations and contacts

No sites are listed yet. Contact the study team or a site near you to ask about taking part.

Basak Pehlivan, Assoc Prof contact

5054083199

bpehlivan@harran.edu.tr

Veli F Pehlivan, MD contact

5327696566

vfpehlivan@harran.edu.tr

About this study

Official title: The Effect of Different PEEP Levels Accompanied by PCV-VG Mode on Respiratory Mechanics and Gas Exchange in Lumbar Surgeries Performed in the Prone Position Under TIVA

This randomized controlled clinical trial aims to compare the effects of two different positive end-expiratory pressure (PEEP) levels (5 cmH₂O and 8 cmH₂O) on respiratory mechanics in patients undergoing lumbar spine surgery in the prone position under total intravenous anesthesia (TIVA). Prone positioning may adversely affect lung compliance and gas exchange, making optimal ventilatory strategies essential. Driving pressure and mechanical power are considered key determinants of ventilator-induced lung stress. This study will evaluate the impact of different PEEP levels on respiratory parameters and intraoperative physiological changes.

Read the detailed description

Prone positioning during lumbar spine surgery is associated with increased intrathoracic pressure, reduced lung compliance, and impaired ventilation-perfusion matching, which may negatively affect respiratory mechanics and gas exchange. Mechanical ventilation strategies, particularly the application of positive end-expiratory pressure (PEEP), play a critical role in preventing atelectasis and optimizing oxygenation.

Pressure-controlled ventilation with volume guarantee (PCV-VG) is a modern ventilation mode that ensures target tidal volume delivery while minimizing airway pressures, thereby reducing the risk of ventilator-induced lung injury. In recent years, driving pressure (ΔP) and mechanical power have emerged as important parameters reflecting lung stress and injury during mechanical ventilation.

This prospective randomized controlled trial aims to evaluate the effects of two different PEEP levels (5 cmH₂O and 8 cmH₂O) on respiratory mechanics and gas exchange in patients undergoing lumbar spine surgery in the prone position under total intravenous anesthesia (TIVA). Patients will be randomly assigned into two groups receiving either 5 cmH₂O or 8 cmH₂O PEEP. Ventilation will be standardized using PCV-VG mode with a tidal volume of 6-8 mL/kg predicted body weight and respiratory rate adjusted to maintain normocapnia.

Hemodynamic parameters and respiratory variables, including peak airway pressure, plateau pressure, dynamic compliance, airway resistance, tidal volume, and end-tidal CO₂, will be recorded at predefined time points. Arterial blood gas analyses will be performed at selected intervals to assess gas exchange.

The primary outcome of the study is driving pressure (ΔP), while secondary outcomes include mechanical power, oxygenation parameters, PaCO₂-EtCO₂ gradient, and physiologic dead space fraction (VD/VT).

The findings of this study are expected to provide clinical evidence regarding the optimal PEEP level in prone lumbar surgery and contribute to improving intraoperative lung-protective ventilation strategies.

Being tested
Mechanical Ventilation (PEEP)
Keywords
PEEP, Driving Pressure, Mechanical Power, PCV-VG Ventilation, Prone Position, Lung Protective Ventilation
Medical subject headings
Intervertebral Disc Displacement

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Mechanical Ventilation (PEEP)Device

    Also called PCV-VG Ventilation, Lung Protective Ventilation

    Mechanical ventilation will be applied using pressure-controlled ventilation with volume guarantee (PCV-VG) mode during prone lumbar surgery under total intravenous anesthesia (TIVA). Two different positive end-expiratory pressure (PEEP) levels (5 cmH₂O and 8 cmH₂O) will be used according to group allocation. Tidal volume will be set at 6-8 mL/kg predicted body weight, and respiratory rate will be adjusted to maintain normocapnia (EtCO₂ 35-40 mmHg).

Study groups in NCT07545733
Study groupRoleWhat they receive
PEEP-5 GroupExperimentalParticipants in this group will receive mechanical ventilation with a positive end-expiratory pressure (PEEP) level of 5 cmH₂O during lumbar spine surgery in the prone position under total intravenous anesthesia (TIVA). Ventilation will be performed using PCV-VG mode with a target tidal volume of 6-8 mL/kg predicted body weight and respiratory rate adjusted to maintain normocapnia.
Receives: Device: Mechanical Ventilation (PEEP)
PEEP-8 GroupExperimentalParticipants in this group will receive mechanical ventilation with a positive end-expiratory pressure (PEEP) level of 8 cmH₂O during lumbar spine surgery in the prone position under total intravenous anesthesia (TIVA). Ventilation will be performed using PCV-VG mode with a target tidal volume of 6-8 mL/kg predicted body weight and respiratory rate adjusted to maintain normocapnia.
Receives: Device: Mechanical Ventilation (PEEP)

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Driving Pressure (ΔP)

    Driving pressure (ΔP), calculated as the difference between plateau pressure (Pplat) and positive end-expiratory pressure (PEEP), will be used as the primary outcome to assess lung stress during mechanical ventilation.

    Measured: Intraoperative period (at predefined time points: T0, T2, T5)

Secondary outcomes (6)
  1. Mechanical Power

    Mechanical power will be calculated to quantify the energy delivered to the respiratory system during mechanical ventilation.

    Measured: Intraoperative period (T0, T2, T5)

  2. Oxygenation (PaO₂/FiO₂ Ratio)

    Oxygenation status will be assessed using the arterial oxygen partial pressure to inspired oxygen fraction (PaO₂/FiO₂) ratio.

    Measured: Intraoperative period (T0, T2, T5)

  3. PaCO₂-EtCO₂ Gradient

    The difference between arterial carbon dioxide pressure (PaCO₂) and end-tidal CO₂ (EtCO₂) will be used to evaluate ventilation-perfusion mismatch.

    Measured: Intraoperative period (T0, T2, T5)

  4. Physiological Dead Space Fraction (VD/VT)

    Physiological dead space fraction will be calculated using the Bohr equation to assess ventilation efficiency.

    Measured: Intraoperative period (T0, T2, T5)

  5. Dynamic Lung Compliance (Cdyn)

    Dynamic compliance will be recorded to evaluate changes in lung mechanics during ventilation.

    Measured: Intraoperative period (all time points)

  6. Peak Airway Pressure (Ppeak)

    Peak airway pressure will be recorded to assess airway pressure changes during mechanical ventilation.

    Measured: Intraoperative period (all time points)

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted22 Apr 2026
  2. Study start15 Aug 2026 (estimated)
  3. Primary completion2 Sep 2026 (estimated)
  4. Study completion3 Oct 2026 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Model description
Participants will be randomly assigned to one of two groups receiving either 5 cmH₂O or 8 cmH₂O PEEP during mechanical ventilation in prone lumbar surgery.
Masking
None (open label)
Enrolment
60 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07545733
Sponsor's protocol ID
REŞIT-PEEP-2026
Acronym
PROPEEP
Status last verified
Aug 2026
First submitted
16 Apr 2026
Last updated
11 Aug 2026
Results posted
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

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