The following is a summary of “Heterogeneous impact of sighs on mortality in patients with acute hypoxemic respiratory failure: insights from the PROTECTION study,” published in the October 2024 issue of Critical Care by Rezoagli et al. 

Researchers conducted a retrospective study to analyze the impact of sigh breaths on mortality in predefined subgroups of patients with acute hypoxemic respiratory failure (AHRF) during assisted mechanical ventilation based on their physiological response to oxygenation and the set levels of positive end-expiratory pressure (PEEP) (High vs. Low-PEEP).  

They randomized patients to pressure support ventilation (PSV) with Sigh (Sigh group) vs PSV with no sigh (No Sigh group). Sighs were delivered as part of the intervention to assess their impact on 28-day mortality. Patients were categorized as responders or non-responders based on their baseline sigh-test.  

The results showed that in responders to the baseline sigh-test, sighs were not associated with differences in 28-day mortality. However, in non-responders, 28-day mortality was lower with sighs (17% vs 36%, log-rank P=0.031). In patients with PEEP > 8 cm H₂O, no difference in mortality was observed with sighs. In patients with Low-PEEP, mortality at 28-day was reduced in patients randomized to sighs (13% vs 31%, log-rank P=0.021). Tidal volume, respiratory rate, and ventilatory ratio decreased with Sigh compared to No Sigh at 7 days. The ventilatory ratio was associated with mortality and successful extubation in non-responders and Low-PEEP.  

They concluded low mortality in AHRF non-responders exposed to Low-PEEP when added Sigh to PSV, suggesting potential benefits in this subgroup. 

Source: annalsofintensivecare.springeropen.com/articles/10.1186/s13613-024-01385-0