Non-Invasive Respiratory Support in “De Novo” Acute Hypoxemic Respiratory Failure: Wich Technique Is Best?

One of the most debated scientific topics in recent years is the role of noninvasive respiratory support techniques in the treatment of de novo acute hypoxemic respiratory failure. Until pre-COVID-19, the most accredited guidelines did not make recommendations for or against the use of these techniques in this clinical condition, and the increased risk of adverse events for patients who failed the noninvasive approach was widely reported in the literature. In recent years, in addition to the pandemic experience, we have seen the widespread use of high-flow nasal cannulas (HFNC) in the emergency department, as well as the production of numerous studies comparing them to the more established techniques of noninvasive ventilation and continuous positive airway pressure (NIV, CPAP), as well as to conventional oxygen therapy (COT). The most recent guidelines recommend the use of HFNC as a first-line technique in the treatment of de novo acute hypoxemic respiratory failure to avoid the need for tracheal intubation. However, the strength of these recommendations remains weak, the quality of the underlying evidence is poor, and their usefulness in deciding which technique to apply to an individual patient is questionable. The progressive establishment of the pathophysiological concept of Patient's Self-Inflicted Lung Injury (P-SILI), a potential risk of additional lung damage in spontaneously breathing patients, has highlighted the importance of assessing each patient's risk of developing this complication, individualizing treatment to the patient's specific needs, and monitoring the patient during treatment. This brief narrative review will illustrate the most recent literature on these topics.