Driving Pressure During Surgeries With High Risk for Postoperative Pulmonary Complications

Overview

The goal of this clinical trial is to compare two different types of perioperative mechanical ventilation (MV), specifically Protective Mechanical Ventilation (PMV) and MV with the lowest possible Driving Pressure (ΔP), in relation to the appearance of postoperative pulmonary complications (PPCs) in adult patients who are operated and have higher risk of PPCs. The main questions it aims to answer are: * Is MV with lower ΔP better than conventional PMV in preventing PPCs in patients with higher risk for PPCs? * Does MV with lower ΔP decrease hospital stay, Intensive Care Unit (ICU) need and mortality? * Does MV with lower ΔP suit better than PMV to lung characteristics and needs intraoperatively? Researchers will compare MV with the lowest possible Driving Pressure (ΔP) to Protective Mechanical Ventilation (PMV) to see if any of this is more protective than the other concerning PPCs. All participants will receive perioperative MV. Half of them will receive conventional Protective Mechanical Ventilation (PMV). This will include well known generally protective settings for mechanical ventilation of patients, concerning volumes, pressures, respiratory rate, inspiratory gases and ventilation maneuvers. The rest of participants will be ventilated with the lowest possible Driving Pressure (ΔP). This will be similar to PMV in the chosen volumes, respiratory rate, inspiratory gases and ventilation maneuvers. However, the pressure inside lung at the end of expiration, eg Positive End Expiratory Pressure (PEEP), will be not be preset for every patient. Initially, the investigators will perform a maneuver that will quantify each individual's lung characteristics and mechanics. According to this, the investigators will find the exact PEEP that seems to suit each patients lungs most, and use this perioperatively, trying to provide lungs the best conditions every time. After the completion of the operation, all the patients will be screened for PPCs, via arterial blood testing and chest X ray, and the results will be statistically analyzed trying to find if any of the forementioned strategies of mechanical ventilation surpasses the other concerning PPCs appearance. PPCs include atelectasis, respiratory failure, bronchospasm, pleural effusion, pneumonia, aspiration and pneumothorax. Furthermore hospital stay, ICU need and mortality will be noted. Finally, measurements of perioperative lung pressures, volumes and derived variables will be noted and compared statistically as well.

Interventions

• Procedure PEEP titration for Minimum Driving Pressure
  This group is mechanically ventilated with Invasive Mechanical Ventilation with Volume Control Ventilation mode with PEEP Initially 8 cm H2O. Afterwards, the lungs are recruited with the aforementioned maneuver. During subsequent derecruitment, PEEP is decreased by 2 cm H20 and compliance is noted in each stage. The goal is to find PEEP with maximum compliance (Cmax). A new recruitment maneuver follows and during derecruitment PEEP is set at the optimum value that was previously defined. VT 8 m
• Procedure Lung Protective Ventilation
  This group is mechanically ventilated with Invasive Mechanical Ventilation with Volume Control Ventilation mode with PEEP 8 cm H2O. VT 8 ml/kg IBW RR --\> PaCO2 = 35-45 mmHg FiO2 0.4 - 0.5 --\> SpO2 \> 93% Recruitment Maneuvers (as described) every hour

Primary outcome measures

• Postoperative Pulmonary Complications [Time frame: Atelectasis -> Within 1 hour in PACURespiratory failure -> Immediately postoperatively & after 30 minutes in PACU.Bronchospasm, Pleural Effusion, Pneumonia, Aspiration Pneumonitis, Pneumothorax -> from immediately postoperative until end of study]

Secondary outcome measures (8)

• Hospital Stay [Time frame: From day of operation until the end of patient stay inside hospital, because of return to home or due to death.]
• ICU need. [Time frame: From day of operation until the end of patient stay inside hospital, because of return to home or due to death.]
• ICU stay [Time frame: From day of operation until the end of patient stay inside hospital, because of return to home or due to death.]
• 28 Day mortality [Time frame: From day of operation until up to 28 days.]
• Mechanical Power (MP) [Time frame: From the moment of beginning of operation until the moment of the end of operation and mechanical ventilation]
• Volume-normalized Mechanical Power (MPcrs) [Time frame: From the moment of beginning of operation until the moment of the end of operation and mechanical ventilation]
• Elastic Power (EP) [Time frame: From the moment of beginning of operation until the moment of the end of operation and mechanical ventilation]
• Volume-normalized Elastic Power (EPcrs) [Time frame: From the moment of beginning of operation until the moment of the end of operation and mechanical ventilation]

Eligibility criteria

Inclusion criteria

• >17 years old
• Surgery with general anesthesia \& invasive mechanical ventilation
• Preoperative ARISCAT score estimation >25

Exclusion criteria

• <18 years old
• Preoperative ARISCAT score estimation <26
• Women during pregnancy or just given birth
• Other type of anesthesia (Not general)
• Contraindication of administration of neuromuscular blockade agents.
• Contraindication of cease of spontaneous ventilation.
• Mechanical ventilation without endotracheal intubation.
• Severe heart failure / Severe cardiac arrhythmia.
• Severe emphysematous lung disease.
• Patient denial of participation in the trial.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Single blind

Primary purpose

Prevention

Study locations

Greece · 1 center

• University Hospital of Patras — Pátrai

Identifiers

NCT: NCT07186933 · 22624 / 4.8.2025

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗