Assessment of nasal pressure swing predicts respiratory support dependency in patients with hypoxic respiratory failure.

Abstract

Background: Monitoring is essential in managing acute hypoxemic respiratory failure (AHRF). Nasal pressure swing (P_nose) may predict high-flow nasal oxygen (HFNO) therapy failure and respiratory support dependency. This study investigates P_nose's predictive value for respiratory support needs and clinical outcomes in AHRF patients initially treated with HFNO.

Methods: This post-hoc analysis included 60 AHRF patients treated with HFNO. Respiratory variables, including P_nose, were assessed at baseline and two hours after HFNO initiation. Patients were classified into high (HG) and low (LG) Pnose groups based on a 5.1 cmH2O threshold. The primary outcome was RS-free survival at day 7; HFNO failure, escalation to non-invasive ventilation (NIV) or mechanical ventilation (MV), mortality, and HFNO weaning time were also analyzed. Predictive accuracy of respiratory indices, including P_nose, was evaluated.

Results: Out of the patients enrolled, 35 were in the HG, and 25 in LG group. HG patients showed a lower RS-free survival at day 7 (adjusted HR=0.26, p < 0.0001), and experienced higher failure rates of HFNO (88 % versus 0 %, p < 0.0001), escalation to NIV (84 % versus 0 %, p < 0.0001), endotracheal intubation (36 % versus 0 %, p < 0.0001), and mortality (24 % versus 6 %, p = 0.0001) compared to LG. Accordingly, RS-free days at day 28 were lower in HG (11 days versus 23 days, p < 0.0001). Finally, among the respiratory variables, P_nose resulted independently associated with the primary outcome (OR=0.64 95 %CI [0.42-0.90], p = 0.02).

Conclusions: In patients with AHRF admitted to the ward and treated by HFNO, P_nose is an independent and accurate factor in forecasting the dependency from RS and survival within the first week.