Non-invasive ventilation for acute hypoxemic respiratory failure: intubation rate and risk factors

Abstract

IntroductionWe assessed rates and predictive factors of non-invasive ventilation (NIV) failure in patients admitted to the intensive care unit (ICU) for non-hypercapnic acute hypoxemic respiratory failure (AHRF).MethodsThis is an observational cohort study using data prospectively collected over a three-year period in a medical ICU of a university hospital.ResultsAmong 113 patients receiving NIV for AHRF, 82 had acute respiratory distress syndrome (ARDS) and 31 had non-ARDS. Intubation rates significantly differed between ARDS and non-ARDS patients (61% versus 35%, P = 0.015) and according to clinical severity of ARDS: 31% in mild, 62% in moderate, and 84% in severe ARDS (P = 0.0016). In-ICU mortality rates were 13% in non-ARDS, and, respectively, 19%, 32% and 32% in mild, moderate and severe ARDS (P = 0.22). Among patients with moderate ARDS, NIV failure was lower among those having a PaO2/FiO2 >150 mmHg (45% vs. 74%, p = 0.04). NIV failure was associated with active cancer, shock, moderate/severe ARDS, lower Glasgow coma score and lower positive end-expiratory pressure level at NIV initiation. Among intubated patients, ICU mortality rate was 46% overall and did not differ according to the time to intubation.ConclusionsWith intubation rates below 35% in non-ARDS and mild ARDS, NIV stands as the first-line approach; NIV may be attempted in ARDS patients with a PaO2/FiO2 > 150. By contrast, 84% of severe ARDS required intubation and NIV did not appear beneficial in this subset of patients. However, the time to intubation had no influence on mortality.

Non-invasive ventilation in hypoxemic acute respiratory failure: is it still possible?

“…Similar to previous reports [19,20], ARDS or cancer patients were associated with more frequent NIV failure, while heart failure was associated with less frequent treatment failure and pneumonia with an intermediate failure rate.…”

High-flow nasal oxygen therapy and noninvasive ventilation in the management of acute hypoxemic respiratory failure

“…Similarly poor outcomes have been observed in cohort studies of ARDS patients treated with NIV (40,41), who represented a majority (almost 70%) of patients with hypoxemic ARF (26,39). Another limitation for NIV in hypoxemic ARF is the high mortality rate (50%) in case of NIV failure (1,39). In the recent large-scale international LUNG SAFE study, severe hypoxemic patients who failed NIV had a higher mortality rate (approximately 43%) than invasively ventilated patients (42).…”

“…More recently, cohort studies including patients treated with NIV for hypoxemic ARF reported a high intubation rate, potentially exceeding 50% (39). Similarly poor outcomes have been observed in cohort studies of ARDS patients treated with NIV (40,41), who represented a majority (almost 70%) of patients with hypoxemic ARF (26,39). Another limitation for NIV in hypoxemic ARF is the high mortality rate (50%) in case of NIV failure (1,39).…”

“…The heterogeneity of patients included in studies comparing NIV to standard oxygen, i.e., patients with hypercapnia or cardiogenic pulmonary edema, may explain high intubation rate variability (7,(35)(36)(37)(38). More recently, cohort studies including patients treated with NIV for hypoxemic ARF reported a high intubation rate, potentially exceeding 50% (39). Similarly poor outcomes have been observed in cohort studies of ARDS patients treated with NIV (40,41), who represented a majority (almost 70%) of patients with hypoxemic ARF (26,39).…”

“…However, establishment of pre-specified intubation criteria to avoid delayed intubation does not seem sufficient to improve patient prognosis in case of NIV failure. In their cohort study of patients treated with NIV for hypoxemic ARF, Thille et al reported no difference in delay of intubation between patients who survived or not after NIV failure (39). Consequently, a randomized controlled trial (Florali study) was conducted by Frat et al to compare three strategies of oxygenation: standard oxygen, HFNC and NIV (10).…”