High-flow nasal oxygen therapy compared with conventional oxygen therapy in hospitalised patients with respiratory illness: a systematic review and meta-analysis.

BACKGROUND: High-flow nasal oxygen therapy (HFNO) is used in diverse hospital settings to treat patients with acute respiratory failure (ARF). This systematic review aims to summarise the evidence regarding any benefits HFNO therapy has compared with conventional oxygen therapy (COT) for patients with ARF. METHODS: Three databases (Embase, Medline and CENTRAL) were searched on 22 March 2023 for studies evaluating HFNO compared with COT for the treatment of ARF, with the primary outcome being hospital mortality and secondary outcomes including (but not limited to) escalation to invasive mechanical ventilation (IMV) or non-invasive ventilation (NIV). Risk of bias was assessed using the Cochrane risk-of-bias tool (randomised controlled trials (RCTs)), ROBINS-I (non-randomised trials) or Newcastle-Ottawa Scale (observational studies). RCTs and observational studies were pooled together for primary analyses, and secondary analyses used RCT data only. Treatment effects were pooled using the random effects model. RESULTS: 63 studies (26 RCTs, 13 cross-over and 24 observational studies) were included, with 10 230 participants. There was no significant difference in the primary outcome of hospital mortality (risk ratio, RR 1.08, 95% CI 0.93 to 1.26; p=0.29; 17 studies, n=5887) between HFNO and COT for all causes ARF. However, compared with COT, HFNO significantly reduced the overall need for escalation to IMV (RR 0.85, 95% CI 0.76 to 0.95 p=0.003; 39 studies, n=8932); and overall need for escalation to NIV (RR 0.70, 95% CI 0.50 to 0.98; p=0.04; 16 studies, n=3076). In subgroup analyses, when considering patients by illness types, those with acute-on-chronic respiratory failure who received HFNO compared with COT had a significant reduction in-hospital mortality (RR 0.58, 95% CI 0.37 to 0.91; p=0.02). DISCUSSION: HFNO was superior to COT in reducing the need for escalation to both IMV and NIV but had no impact on the primary outcome of hospital mortality. These findings support recommendations that HFNO may be considered as first-line therapy for ARF. PROSPERO REGISTRATION NUMBER: CRD42021264837.

Portable evaluation of obstructive sleep apnea in adults: A systematic review.

Obstructive sleep apnea (OSA) is a significant healthcare burden affecting approximately one billion people worldwide. The prevalence of OSA is rising with the ongoing obesity epidemic, a key risk factor for its development. While in-laboratory polysomnography (PSG) is the gold standard for diagnosing OSA, it has significant drawbacks that prevent widespread use. Portable devices with different levels of monitoring are available to allow remote assessment for OSA. To better inform clinical practice and research, this comprehensive systematic review evaluated diagnostic performances, study cost and patients' experience of different levels of portable sleep studies (type 2, 3, and 4), as well as wearable devices and non-contact systems, in adults. Despite varying study designs and devices used, portable diagnostic tests are found to be sufficient for initial screening of patients at risk of OSA. Future studies are needed to evaluate cost effectiveness with the incorporation of portable diagnostic tests into the diagnostic pathway for OSA, as well as their application in patients with chronic respiratory diseases and other comorbidities that may affect test performance.