Oxygen supplementation is widely used to enhance oxygen delivery and to treat or prevent hypoxia; however, it requires careful management to avoid the harmful effects of excessive oxygen exposure. Both hyperoxia (inspiratory oxygen fraction exceeding 0.21) and hyperoxemia (arterial oxygen tension oxygen partial pressure [PaO ₂ ] > 100 mmHg) can contribute to lung injury, promote systemic vasoconstriction, and increase the production of reactive oxygen species, which can impair macromolecular and cellular functions. Conversely, in certain situations, hyperoxemia may provide benefits, such as hemodynamic stabilization in hyperdynamic shock, immunomodulation, and bactericidal effects. The literature presents conflicting evidence regarding the impact of different oxygen targets (i.e., PaO ₂ and/or peripheral saturation of oxygen [SpO ₂ ]) on both short- and long-term outcomes in patients with acute critical conditions, such as acute respiratory distress syndrome, sepsis, cardiac arrest, and acute central nervous system injuries. These discrepancies may stem from the small differences between the oxygenation targets used in randomized trials, the physiological limitations of PaO ₂ and SpO ₂ targets, which reflect blood oxygen content rather than oxygen delivery, the lack of measurements of microvascular function or oxygen delivery, and the heterogeneity in treatment response. Furthermore, advanced analytical methods (e.g., machine learning) are emerging as promising tools to implement population enrichment strategies. By refining patient sub-group identification, these approaches can significantly optimize precision medicine, enabling more personalized oxygen therapy tailored to individual patient characteristics.

ICU survivors suffer from various long-term physical and psychological impairments. Memories from the critical illness may influence long-term psychological outcome. In particular, the role of ICU memories in COVID-19 critically ill patients is unknown. In a prospective observational study, we aimed to investigate patients’ memories from the experience of critical illness and their association with a six-month psychological outcome involving quality of life evaluation. Patients’ memories were investigated with ICU Memory tool, while psychological outcome and quality of life were evaluated by means of a battery of validated questionnaires during an in-person interview at the follow-up clinic. 149 adult patients were enrolled. 60% retained memories from pre-ICU days spent on a general ward, while 70% reported memories from the in-ICU period. Delusional memories (i.e., memories of facts that never happened) were reported by 69% of patients. According to a multivariable analysis, the lack of pre-ICU memories was an independent predictor of worse psychological outcomes in terms of anxiety, depression and Post-traumatic Stress Disorder (PTDS). Factors associated with long-term outcome in ICU survivors are not still fully understood and patients’ experience during the day spent before ICU admission may be associated with psychological sequelae.

Right-to-left intracardiac shunting may complicate patent foramen ovale, with percutaneous closure being the standard treatment. We present the case of a 63 year old man admitted for percutaneous patent foramen ovale (PFO) closure due to severe right-to-left shunting. Despite treatment with diuretics and noradrenaline, he developed persistent hypoxemia with pulmonary edema. Intubation was initially avoided because of the risk of worsening shunt physiology and anticipated airway management difficulties. To optimize oxygenation while maintaining femoral access for intervention, awake veno-venous extracorporeal membrane oxygenation (ECMO) was initiated, resulting in a marked improvement in oxygenation. The patient subsequently underwent intubation, diagnostic imaging, and successful PFO closure. Extracorporeal membrane oxygenation was weaned 2 days later, and he was discharged from the intensive care unit (ICU) to the ward. This case demonstrates that awake veno-venous ECMO (V-V-ECMO) can serve as a bridging strategy in patients with PFO-related right-to-left shunting when mechanical ventilation carries substantial risks. Careful multidisciplinary evaluation is essential to weigh the potential benefits of ECMO against the risks of cannulation and shunt dynamics.