Association between step-down disposition based on the HACOR score and mortality in ED patients treated with non-invasive ventilation.

In this retrospective study, we aimed to find reliable criteria that allow the identification of patients, treated with NIV for acute respiratory failure in the High-Dependency Unit in the earliest phase, who could continue treatment safely in the ordinary ward. We included all patients treated with NIV in the ED-HDU at Careggi University-Hospital, from July 2021 to December 2022. The HACOR score was calculated daily, and the discharge to the ward was considered Appropriate in the presence of the following criteria: 1) HACOR score ≤ 2; 2) not being dependent on NIV, which meant the possibility of alternating NIV with conventional oxygen treatment or High-Flow Nasal Cannula. The primary endpoint was all-cause in-hospital mortality. We included 297 patients, with a mean age of 79 ± 11 years, 57% female, 69% with hypercapnic respiratory failure. After 24 h, the HACOR score was ≤ 2 in 113 (38%) patients, with a mortality of 11% vs 21% for those with an HACOR score > 2 (p = 0.029). In total, 235 (79%) patients were transferred to the general ward, 110 as Inappropriate and 125 as Appropriate. In-hospital mortality rate was higher in the Inappropriate than in the Appropriate group (21% vs 7%, p = 0.004). After excluding the 64 patients treated with NIV as the ceiling treatment, 28 in the "Appropriate transfer" and 36 "Inappropriate transfer", we confirmed the increased mortality in patients with inappropriate transfer (14% vs 4%, p = 0.026). Therefore, patients with an HACOR score ≤ 2, not dependent on NIV, could be safely transferred to the ordinary ward to continue their ventilatory support.