Primary Graft Dysfunction, Pronation, Bilateral Lung Transplants

Early Prone Positioning as a Rescue Therapy for Severe Primary Graft Dysfunction After Bilateral Lung Transplant.

Proning manoeuvre as an early treatment for acute severe hypoxic respiratory failure has been implemented recently during the COVID-19 pandemic. This method was proposed more than fifty years ago to improve gas exchange : Proning Severe ARDS (PROSEVA) trial, however, was the milestone which demonstrated mortality benefit in patients with severe ARDS. Nevertheless, few analysis were performed on the effects of the prone position after lung transplantion (LT). The aim of the study is therefore to relate LT primary graft dysfunction (PGD) pathophysiology, which occurs in postoperative setting, to prone-positioning effects on ventilation-perfusion matching, improved lung compliance and clinical outcomes of impairedorgan patients.

Lung transplant is the final stage of intervention in dramatic respiratory failure unresponsive to other medical or surgical treatments: reduced disability, improved life quality and extended life are outweighed by still high mortality and morbidity of LT, compared to other solid organs transplants. LT patient survival is undermined, above all, by PGD onset up to 72h in postoperative scenario. Acute lung injury, characterized by reperfusion and ischemia damage, evolves in pulmonary edema and severely inflammed graft status. Tipical radiological findings are bilateral spreading infiltrates, whose treatment was until some years ago mainly supportive, i.e. protective mechanical ventilation and fluid restriction. Two retrospective studies recently demonstrated favorable oxygenation response in terms of PaO2/fraction-of-inspired-oxygen (FiO2) ratio and lung compliance. Our purpose was to broaden gas-exchange results by the analysis of short-term outcomes (i.e duration of mechanical ventilation, reintubation or tracheostomy, anastomotical complications, organ rejection in 30 days, acute kindney injury development and/or filtration necessity, hospital length and mortality). Our aim is to assess through this pilot study if early pronation (realized within 24 hours from admission) has a more favorable outcome on patients developing moderate/severe PGD within the first 24 postoperative hours.

Inclusion Criteria:

• Age > 18 y.o.
• First bilateral lung transplant
• PGD grade 2 or 3 within 24 hours from ICU admission Admission to ICU for post-operative monitoring after LTx
• Written informed consent obtained

Exclusion Criteria:

• Age < 18 years old
• PGD<2
• Single transplant
• Re-transplant
• IMV, venous-venous (V-V) or venous-arterial (V-A) extracorporeal membrane oxygenation (ECMO) before surgery
• Contraindications to prone positioning
• Refusal of consent