Surfactant alterations following donation after cardiac death donor lungs

The use of lungs from donation after cardiac death (DCD) donors is one of the strategies to increase the donor pool. The aim of this study was to assess the surfactant alterations in DCD donor lungs. Pigs were sacrificed and left untouched for 1 (DCD1), 2 (DCD2) and 3 (DCD3) h. Lungs were then topically cooled with saline for 1, 2 or 3 h to reach a total ischemic time of 4 h. Heart‐beating donors (HBD) served as control group. Bronchoalveolar lavage (BAL) samples were assessed for protein levels and surfactant function. Left lungs were prepared for ex‐vivo evaluation. Pulmonary vascular resistance (PVR), oxygenation, airway pressure (AWP) and wet‐to‐dry weight ratio were significantly different between HBD and DCD3 groups (P < 0.05). BAL protein levels were statistically higher in DCD3 compared with HBD group (P < 0.05). Surface tension and surface tension measured at minimal bubble diameter (adsorption) were lower in HBD compared with DCD groups (P < 0.05). Adsorption was also lower in DCD1 compared with DCD2 (P < 0.05). Adsorption and surface tension were correlated with oxygenation and AWP (P < 0.05). This study has shown that lung function deteriorates with increasing warm ischemic time intervals. BAL protein, surface tension, adsorption, peak AWP and PVR increase significantly after 2 h of warm ischemia together with a significant reduction of the ratio PaO₂/FiO₂.