The current COVID-19 pandemic has aggravated pre-existing oxygen supply gaps all over the world. In fact, oxygen shortages occurred in affluent areas with highly developed healthcare systems. The state-of-affairs created much suffering and resulted in potentially preventable deaths. Meanwhile, several international activities have been initiated to improve oxygen availability in the long-term by creating new networks of oxygen plants and supply channels. However, disasters such as the current pandemic may require rapid, autarkic oxygen production. Therefore, we determined whether oxygen resilience could conceivably be improved through self-made oxygen generators using material that is easily available even in remote areas. The team comprised engineers and physicians with hands-on experience in low- and middle-income countries. We constructed and tested self-made setups for water hydrolysis and membrane-based oxygen purification. We must conclude, however, that the massive amounts of oxygen patients with COVID-19 require cannot be reasonably met with such simple measures, which would require high efforts and hold potential risks.

It is hypothesized that tissue dysoxia and O2 debt are major factors in the development and the propagation of multiple organ failure in critically ill patients. Dysoxia is the result of an abnormal relationship between O2 supply (DO2) and O2 demand and translates into increased anaerobic metabolism and tissue and blood lactate concentration. First-line therapeutic strategies used to avoid the development of an O2 debt involve correction of cardiac output, haemoglobin, and O2 saturation in order to increase DO2 above its critical value. They are not sufficient, however, to ensure appropriate end-organ perfusion and oxygenation. The adequacy of cardiac output towards tissue metabolic requirements may be appreciated by venous-to-arterial and gut mucosal-to-arterial PCO2 differences. This review details these strategies and discusses their usefulness in current practice.