Non-invasive ventilation for acute hypoxaemic respiratory failure: a propensity-matched cohort study

Abstract

BackgroundNon-invasive ventilation (NIV), although effective in treating hypercapnic respiratory failure, has not demonstrated the same efficacy in treating acute hypoxaemic respiratory failure. We aimed to examine the effect of NIV use on ventilator-free days in patients with acute hypoxaemic respiratory failure admitted to the intensive care unit (ICU).MethodsWe conducted a retrospective study of patients admitted to the ICU with acute hypoxaemic respiratory failure at Waikato Hospital, New Zealand, from 1 January 2009 to 31 December 2018. Patients treated with NIV as the initial oxygenation strategy were compared with controls treated with early intubation. The two groups were matched using a propensity score based on baseline characteristics. The primary outcome was the number of ventilator-free days at day 28. The secondary outcomes were ICU and hospital length of stay and in-hospital mortality.ResultsOut of 175 eligible patients, 79 each out of the NIV and early intubation groups were matched using a propensity score. Early NIV was associated with significantly higher median ventilator-free days than early intubation (17 days vs 23 days, p=0.013). There was no significant difference in median ICU length of stay (112.5 hours vs 117.7 hours), hospital length of stay (14 days vs 14 days) or in-hospital mortality (31.6% vs 37.9%) between the NIV and the early intubation group.ConclusionCompared with early intubation, NIV use was associated with more ventilator-free days in patients with hypoxaemic respiratory failure. However, this did not translate into a shorter length of stay or reduced mortality based on our single-centre experience.

Acute dyspnea in the emergency department: a clinical review

“…The use of NIV in patients with hypoxemic ARF have been associated with a greater and faster improvement in respiratory rate and oxygenation compared to standard oxygen therapy [ 138 , 139 ]. In some studies, facemask NIV shortened ICU stay [ 138 , 140 , 141 ] and lowered the intubation rate [ 138 , 141 ], but in others did not [ 142 , 143 ]. In terms of ICU mortality, no benefit was reported by many studies comparing facemask NIV with standard oxygen therapy or mechanical ventilation [ 138 , 140 – 144 ].…”

“…In some studies, facemask NIV shortened ICU stay [138,140,141] and lowered the intubation rate [138,141], but in others did not [142,143]. In terms of ICU mortality, no benefit was reported by many studies comparing facemask NIV with standard oxygen therapy or mechanical ventilation [138,[140][141][142][143][144]. A possible explanation for these discordant results is that successful NIV improves the outcome of patients by avoiding intubation and its related complications; however, intubation after NIV failure (defined as intubation either due to patient intolerance to NIV or ensuing medical indication) is associated with higher mortality rates compared to patients who are intubated without prior NIV [145,146].…”