Limitations of arterial partial pressure of oxygen to fraction of inspired oxygen ratio for the evaluation of donor lung function. Issue 11 (18th July 2022)

• Record Type: Journal Article
• Authors: Fumagalli, Jacopo; Colombo, Sebastiano Maria; Scaravilli, Vittorio; Gori, Francesca; Pesenti, Antonio; Zanella, Alberto; Grasselli, Giacomo
• Is Part Of: Artificial organs. Volume 46:Issue 11(2022)
• Page Start: 2313
• Page End: 2318
• Publication Date: 2022-07-18
• Subjects: ex vivo lung perfusion -- intrapulmonary shunt -- lung transplantation -- mixed venous oxygen saturation -- multiorgan donor; Artificial organs -- Periodicals; 617.956
• DOI: 10.1111/aor.14350
• Languages: English
• ISSNs: 0160-564X

Abstract

Abstract: Background: Evaluation of donor lung function relies on the arterial oxygen partial pressure to inspired oxygen fraction ratio (PaO2 /FiO2 ) measurement. Hemodynamic, metabolic derangements, and therapeutic intervention occurring during brain dead observation may influence the evaluation of gas exchange. Methods: We performed a mathematical analysis to explore the influence of the extrapulmonary determinants on the interpretation of PaO2 /FiO2 in the brain‐dead donor and during Ex‐Vivo Lung Perfusion (EVLP). Results: High FiO2 and increased mixed venous oxygen saturation, caused by increased delivery and reduced consumption of oxygen, raise the PaO2 /FiO2 despite substantial intrapulmonary shunt. Anemia does not modify the PaO2 /FiO2 —intrapulmonary shunt relationship. During EVLP, the reduced artero‐venous difference in oxygen content increases the PaO2 /FiO2 without this corresponding to an optimal graft function, while the reduced perfusate oxygen‐carrying capacity linearizes the PaO2 /FiO2 —intrapulmonary shunt relationship. Conclusions: Adopting PaO2 /FiO2 to evaluate graft suitability for transplantation should account for extrapulmonary factors affecting its interpretation. Abstract :