Effect of Lung Protective One-lung Ventilation With Fix and Variable PEEP on Oxygenation and Outcome

Study Overview
=================
Brief Summary
-----------------
During One-lung ventilation, the use of lower tidal volumes (VT) is helpful to avoid over-distension, provide sufficient oxygenation, but can result in increased atelectasis. Nevertheless, it is not known if, during one-lung ventilation with constant low VT, moderate levels of PEEP combined with lung recruitment maneuvers are superior to variable PEEP for intraoperative oxygenation and protection against PPCs. Aim of the study is to compare a strategy using constant tidal volume with recruitment maneuvers versus variable PEEP with recruitment maneuvers during thoracic surgery in adults. The investigators hypothesize that in adult, non-obese patients undergoing thoracic surgery under standardized OLV with variable PEEP and recruitment maneuvers as compared to constant PEEP without recruitment maneuvers prevent PPCs. Patients will be randomly assigned to one of two groups: FIX TIDAL VOLUME GROUP (Groupfix): mechanical ventilation with constant (6 ml/kgIBW) tidal volume and PEEP of 5 cmH2O with recruitment maneuvers VARIABLE TIDAL VOLUME GROUP (Groupvar): mechanical ventilation with constant (6 ml/kgIBW) tidal volume with variable PEEP with recruitment maneuvers.

Detailed Description
-----------------
Lung separation will be performed by DLT technique. Mechanical ventilation will be applied in volume-controlled mode. During two-lung ventilation, VT will be set at 8 mL/kg predicted body weight. During one-lung ventilation, in GroupFix VT will be decreased to 6 mL/kg PBW with 5 cmH2O PEEP. In GroupVar VT mechanical ventilation with constant (6 ml/kgIBW) tidal volume with variable PEEP with recruitment maneuvers.

Official Title
-----------------
Effect of Lung Protective One-lung Ventilation With Fix and Variable Positive End-expiratory Pressure (PEEP) on Oxygenation and Outcome: Randomized, Controlled Trial

Conditions
-----------------
Hypoxemia, Pulmonary Sepsis, ARDS, Human, Pneumonia

Intervention / Treatment
-----------------
* Other: Change of ventilatory settings


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Patient scheduled for open thoracic or video-assisted thoracoscopic surgery under general anesthesia requiring OLV (no emergency surgery) BMI < 35 kg/m2 Age ≥ 18 years Expected duration of surgery > 60 min Expected duration of anesthesia > 90 min Exclusion Criteria: COPD GOLD 3+4, lung fibrosis, documented bullae, severe emphysema, pneumothorax uncontrolled asthma NYHA 3+4, CCS 3+4 previous thoracic surgery ARDS (Berlin definition) documented pulmonary arterial hypertension > 40 mmHg syst documented or suspected neuromuscular disease (thymoma, myasthenia) planned mechanical ventilation after surgery bilateral procedures lung separation with other method than DLT (eg diff. airway, trachestomy) surgery in prone position persistent hemodynamic instability, intractable shock intracranial injury or tumor enrollment in other interventional study or refusal of informed consent pregnancy (excluded by anamnesis and/or laboratory analysis)

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: Group Fix:One-lung ventilation with constant PEEP<br>Controll group: lung protective one-lung ventilation with fix positive end-expiratory pressure (PEEP) | |
| Active Comparator: Group Variable:One-lung ventilation with variable PEEP<br>Variable group: lung protective one-lung ventilation with variable positive end-expiratory pressure (PEEP) | Other: Change of ventilatory settings<br>* Change of Positive End-Exspiratory Pressure during one-lung ventilation<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Intraoperative oxygenation | PaO2 < 60 mmHg | 1 day | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Postoperative pulmonary complications | Infiltrate on chest X-ray, fever, laboratory and physical signs of infection | 90 days | 
| Postoperative extra-pulmonary complications | new atrial fibrillation | 90 days | 
| 30 day survival/mortality | number of death within 30 days after surgery | 30 days | 
| 90 day survival/mortality | number of death within 90 days after surgery | 90 days |