High‐flow nasal cannulae for respiratory support in adult intensive care patients

Background High‐flow nasal cannulae (HFNC) deliver high flows of blended humidified air and oxygen via wide‐bore nasal cannulae and may be useful in providing respiratory support for adults experiencing acute respiratory failure, or at risk of acute respiratory failure, in the intensive care unit (ICU). This is an update of an earlier version of the review. Objectives To assess the effectiveness of HFNC compared to standard oxygen therapy, or non‐invasive ventilation (NIV) or non‐invasive positive pressure ventilation (NIPPV), for respiratory support in adults in the ICU. Search methods We searched CENTRAL, MEDLINE, Embase, CINAHL, Web of Science, and the Cochrane COVID‐19 Register (17 April 2020), clinical trial registers (6 April 2020) and conducted forward and backward citation searches. Selection criteria We included randomized controlled studies (RCTs) with a parallel‐group or cross‐over design comparing HFNC use versus other types of non‐invasive respiratory support (standard oxygen therapy via nasal cannulae or mask; or NIV or NIPPV which included continuous positive airway pressure and bilevel positive airway pressure) in adults admitted to the ICU. Data collection and analysis We used standard methodological procedures as expected by Cochrane. Main results We included 31 studies (22 parallel‐group and nine cross‐over designs) with 5136 participants; this update included 20 new studies. Twenty‐one studies compared HFNC with standard oxygen therapy, and 13 compared HFNC with NIV or NIPPV; three studies included both comparisons. We found 51 ongoing studies (estimated 12,807 participants), and 19 studies awaiting classification for which we could not ascertain study eligibility information. In 18 studies, treatment was initiated after extubation. In the remaining studies, participants were not previously mechanically ventilated. HFNC versus standard oxygen therapy HFNC may lead to less treatment failure as indicated by escalation to alternative types of oxygen therapy (risk ratio (RR) 0.62, 95% confidence interval (CI) 0.45 to 0.86; 15 studies, 3044 participants; low‐certainty evidence). HFNC probably makes little or no difference in mortality when compared with standard oxygen therapy (RR 0.96, 95% CI 0.82 to 1.11; 11 studies, 2673 participants; moderate‐certainty evidence). HFNC probably results in little or no difference to cases of pneumonia (RR 0.72, 95% CI 0.48 to 1.09; 4 studies, 1057 participants; moderate‐certainty evidence), and we were unc