“…[44][45][46][47] Initially introduced and tested within the Intensive Care Units (ICUs), NIV was later also used outside the ICUs, in semi-intensive setting or even in the common wards, with consequent greater accessibility to a wider population of patients. [48][49][50] The use of NIV outside the ICUs is the major advantage of this ventilatory technique, with the possibility of intervention at an early stage, for levels of respiratory acidosis mild or mild to moderate, for which there is no indication for invasive mechanical ventilation in ICU.…”