A novel concept for evaluation of pulmonary function utilizing PaO2/FiO2 difference at the distinctive FiO2 in cellularex vivolung perfusion—an experimental study

Abstract

For more accurate lung evaluation in ex vivo lung perfusion (EVLP), we have devised a new parameter, PaO 2 /FiO 2 ratio difference (PFD); PFD 1-0.4 = P/F ratio at FiO 2 1.0 -P/F ratio at FiO 2 0.4. The aim of this study is to compare PFD and transplant suitability, and physiological parameters utilized in cellular EVLP. Thirty-nine human donor lungs were perfused. At 2 h of EVLP, PFD 1-0.4 was compared with transplant suitability and physiological parameters. In a second study, 10 pig lungs were perfused in same fashion. PFD 1-0.4 was calculated by blood from upper and lower lobe pulmonary veins and compared with lobe wet/dry ratio and pathological findings. In human model, receiver operating characteristic curve analysis showed PFD 1-0.4 had the highest area under curve, 0.90, sensitivity, 0.96, to detect nonsuitable lungs, and significant negative correlation with lung weight ratio (R 2 = 0.26, P < 0.001). In pig model, PFD 1-0.4 on lower and upper lobe pulmonary veins were significantly associated with corresponding lobe wet/dry ratios (R 2 = 0.51, P = 0.019; R 2 = 0.37, P = 0.060), respectively. PFD 1-0.4 in EVLP demonstrated a significant correlation with lung weight ratio and allowed more precise assessment of individual lobes in detecting lung edema. Moreover, it might support decision-making in evaluation with current EVLP criteria. Transplant International 2019; 32: 797-807 Key words donor lung assessment, ex vivo lung perfusion, lung lobes assessment, lung transplantation, PaO 2 / FiO 2 ratio, PaO 2 /FiO 2 ratio difference

Prone ex vivo lung perfusion protects human lungs from reperfusion injury

“…This difference might explain the difference of inflammatory tissue cytokine levels. The favorable results of these series of prone EVLPs we reported, 13 suggested that some benefits of prone positioning in the clinical setting might in part translate to lung performance during EVLP along with other promising therapies to prevent IRI in EVLP; anti‐inflammatory drugs, 14,15 immunosuppressive drugs, 16,17 technical EVLP amendments, 18 and stem cell‐based approaches 19,20 …”

A Split-Lung Ex Vivo Perfusion Model for Time- and Cost-Effective Evaluation of Therapeutic Interventions to the Human Donor Lung

“…Research initially focused on establishing optimal perfusion protocols, parameters for functional lung assessment, and, in clinical studies, their impact on, or correlation with, patient outcomes [ 2 , 3 ]. Recent studies have proposed more accurate methods of assessment, including the CLUE score [ 10 ] and the “PaO 2 /FiO 2 ratio difference” (the difference between PaO 2 /FiO 2 at a FiO 2 of 1.0 and 0.4) [ 11 ]. Lately, research has shifted focus to more sophisticated biomarkers and to assessing the efficacy of interventions on lung function or in reducing risks after implantation.…”

Ex Vivo Lung Perfusion: A Review of Research and Clinical Practices

“…However, the physiology responsible for this improvement in function is still unclear. 42,43 The efficacy of mobile EVLP is currently being evaluated. The initial experience of using the OCS had been reported by the Hanover and Madrid groups.…”