A Meta-Analysis of Remote Ischemic Preconditioning in Lung Surgery and Its Potential Role in COVID-19

Purpose: To determine the effects of remote ischemic preconditioning (RIPC) on pulmonary gas exchange in people undergoing pulmonary surgery and discuss a potential role of RIPC in COVID-19. Method:A search for studies examining the effects of RIPC after pulmonary surgery was performed. RevMan was used for statistical analyses examining measures of A-aDO2, PaO2/FiO2, respiratory index (RI), a/A ratio and PaCO2 obtained earlier after surgery (i.e., 6-8 hours) and later after surgery (i.e., 18-24 hours). Results: Four trials were included (N = 369 participants). Significant (p < 0.05) overall effects of RIPC were observed early after surgery on A-aDO2 and RI (SMD = -0.84 and SMD = -1.23, respectively), and later after surgery on RI, PaO2/FiO2, and a/A ratio (SMD = -0.39, 0.72, and 1.15, respectively) with the A-aDO2 approaching significance (p = 0.05; SMD = -0.45). Significant improvements in inflammatory markers and oxidative stress after RIPC were also observed. Conclusions:RIPC has the potential to improve pulmonary gas exchange, inflammatory markers, and oxidative stress in people with lung disease undergoing lung surgery and receiving mechanical ventilation. These potential improvements may be beneficial for people with COVID-19, but further investigation is warranted.