Very Low Tidal Volume vs Conventional Ventilatory Strategy for One-lung Ventilation in Thoracic Anesthesia

Very Low Tidal Volume vs Conventional Ventilatory Strategy for One-lung Ventilation in Thoracic Anesthesia

Multicenter Randomized Trial on Protective Ventilation Versus Conventional Ventilation During OLV in Patients Undergoing Thoracic Surgery

The purpose of this study is to determine if a protective ventilatory strategy during one-lung ventilation (OLV) based on low tidal volume, PEEP and alveolar recruitment maneuver can reduce Acute Respiratory Distress Syndrome (ARDS) and Postoperative pulmonary complications (PPCs) after major pulmonary resection. Primary endpoint: Evaluation of postoperative ARDS incidence Secondary endpoint: Evaluation od PPC incidence and postoperative outcomes (other complications, unplanned Intensive Care Admission, hospital and ICU length of stay, in-hospital mortality)

Pulmonary postoperative complications (PPCs) are the most frequent adverse events after thoracic surgery. Acute respiratory distress syndrome (ARDS) is the most severe among PPCs. Injurious mechanical ventilation is a recognized risk factor associated with ARDS and PPCs after major thoracic surgery. International literature reports a wide use of tidal volume around 5-6 ml/kg predicted body weight (PBW) during one lung ventilation (OLV) but variable use of PEEP and alveolar recruitment maneuver (ARM). The aim of this multicenter, randomized, single blind study is to determine if a protective ventilatory strategy during OLV based on low tidal volume, PEEP and alveolar recruitment maneuver compared to conventional strategy can reduce ARDS and PPCs after major pulmonary resection. Primary outcome is the incidence of in-hospital ARDS. Secondary outcomes are in-hospital incidence of postoperative pulmonary complications (PPCs), major cardiovascular events, unplanned Intensive Care Unit admission, in-hospital length of stay and mortality RANDOMIZATION Patients are randomly assigned to receive protective or conventional OLV according to a computer-generated randomization list (1:1 ratio) before anesthesia induction. Patients are blinded to the treatment. Anesthesiologists and surgeons are unblinded to the treatment during the surgical procedure and the postoperative outcome assessment. MEASUREMENTS Intraoperative collection of ventilatory settings, airway pressures, arterial blood gases analysis at the following time points: T1: two lung ventilation in supine position before placing the patient in lateral decubitus; T2: 30 minutes after OLV start; T3: 60 minutes after OLV start; T4: 20 minutes after lobectomy/pneumonectomy (during OLV); T5: 15 minutes after ARM in supine position and during two lung ventilation. Postoperative data collection 1, 12, 24, 36, 48 hours after surgery and at discharge. Arterial blood gas analysis will be performed 1 hour after extubation and 24 and 72 hours after surgery (or in case of respiratory insufficiency).

Two-lung ventilation (TLV): tidal volume = 8 mL / kg PBW, peak airway pressure ≤ 25 cm H2O, I: E = 1:2; after lung re-expansion to the closure of the chest will set a PEEP of 5 cmH2O OLV (OLV): 4 mL / kg PBW, peak airway pressure ≤ 35 cmH2O, respiratory rate <30, I:E = 1:2 / 1:3. During OLV in case of desaturation (before increasing the FiO2) and every 60 minutes alveolar recruitment maneuvers followed by the setting of PEEP to 5 cmH2O

Two-lung ventilation (TLV): tidal volume = 8 mL / kg PBW, peak airway pressure ≤ 25 cmH2O; I: E = 1:2; after lung re-expansion to the closure of the chest PEEP set to 5 cmH2O OLV (OLV): 6 mL / kg PBW, peak airway pressure ≤ 35 cmH2O; I: E = 1:2.

Inclusion Criteria: Patients ≥ 18 years ASA IV Elective thoracotomies or thoracoscopic major lung resection surgery (lobectomy, bilobectomy, pneumonectomy) Exclusion Criteria: Emergency surgery Wedge resection or atypical resection Non-resective lung surgery requiring OLV Patients < 18 years BMI < 20 and BMI > 29 Heart disease with ejection fraction <50% and/or severe valvulopathy Pulmonary hypertension Renal failure requiring dialytic treatment Drug addiction Mental retardation, depression and psychiatric disease Motor or sensory deficit Pregnancy

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