Prone Positioning as a Bridge to Recovery From Refractory Hypoxemia After Oversized Lung Transplant

Size matching is an important challenge in lung transplantation. Although the survival rate after lung transplantation with an oversized allograft was improved, it is associated with substantial immediate postoperative morbidity and mortality. Prone positioning is a rescue therapy showing improved outcomes in acute respiratory distress syndrome. We present a case of immediate postoperative refractory hypoxemia after oversized lung transplantation treated by prone positioning.

A 62-year-old man was transferred to our hospital by our extracorporeal membrane oxygenation (ECMO) transport team because of acute exacerbation of idiopathic pulmonary fibrosis. He underwent bilateral lung transplantation through bilateral anterior thoracotomy. For size matching between donor and recipient, multiple wedge resection and lingular segmentectomy were performed, but an oversized lung was implanted. On the immediate postoperative day, chest radiography revealed haziness in the left lower quadrant and the patient had an increased O₂ requirement; he could not be weaned from venovenous (VV) ECMO. Chest computed tomography revealed left lower lobar atelectasis and primary graft dysfunction. To revert the atelectatic portion, improve ventilation/perfusion mismatch, and avoid high ventilation pressure, we performed the recruitment maneuver. Despite this, his blood gas profile did not improve. Therefore, we applied prone positioning with VV ECMO. After conversion to the prone positioning, the hypoxia corrected and the tidal volume increased. After 20 hours, he was changed to the supine position. Thereafter, arterial blood gas analyses were stable and he could be weaned from ECMO. He was discharged on postoperative day 57 and maintained good respiratory function.

This case demonstrated the safety and feasibility of prone positioning during the immediate postoperative period after lung transplant by bilateral anterior thoracotomy. Prone positioning successfully reversed postoperative atelectasis and improved primary graft dysfunction after oversized lung transplant.