Lung Transplantation (LuTX) is the curative treatment for selected patients with end-stage lung disease. Primary Graft Dysfunction (PGD), a specific form of respiratory failure occurring within the first 72 hours after graft reperfusion, represents the most common complication after LuTX.

Actual recommendation regarding management of mechanical ventilation of the lung graft immediately after LuTX are based only on opinion experts and not on clinical trials. Optimization of Positive End-Expiratory Pressure might contribute to both prevention and treatment of PGD.

In this interventional single-center non-pharmacological study (with medical device), in the immediate postoperative period of patients who are undergone LuTX, we will evaluate the effects of varying levels of PEEP upon: - lung and chest wall mechanics, - intrapulmonary shunt fraction; - distribution of ventilation and perfusion; - gas exchange.

The final aim is to find the optimal level of PEEP in this patient's cohort

Inclusion Criteria:

• Recipient of LUTX
• Age > 18 years
• Signed informed consent

Exclusion Criteria:

• Age < 18 years
• Already undergone LUTX
• Major hemodynamic instability along the 24 hours following LUTX: systolic arterial pressure < 90 mmHg and/or heart rate > 120 beat/min and/or high dose vasopressor requirement (norepinephrine > 0.3 mcg/kg/min and/or epinephrine > 0.2 mcg/kg/min and/or dobutamine > 8mcg/kg/min)
• Documented post-LUTX endobronchial plasma leak requiring high levels of PEEP > 15 cmH2O

Deidentified data will be shared with other researchers upon explicit request