Automatic versus Manual Oxygen Titration in Patients Requiring Supplemental Oxygen in the Hospital: A Systematic Review and Meta-Analysis

<b><i>Background:</i></b> Closed-loop oxygen titration devices have been developed to avoid periods of hypoxemia and hyperoxemia, both detrimental to patients hospitalized for respiratory failure and requiring supplemental oxygen. However, their clinical impact remains unknown. <b><i>Objective:</i></b> To compare the effect of automatic versus manual oxygen titration on clinical outcomes in pediatric and adult patients requiring supplemental oxygen in the hospital. <b><i>Methods:</i></b> We conducted a systematic review and meta-analysis of randomized controlled trials. We searched MEDLINE, EMBASE, and CENTRAL electronic databases (from inception to August 2018), and conference proceedings of major societies in respiratory medicine (2015–2018). Randomized controlled trials were included if they compared automatic to manual oxygen titration in hypoxemic inpatients and if they assessed at least one of the following: length of hospital stay (primary outcome), length of oxygen therapy, need and duration of mechanical ventilation, mortality, percentage of time within, above, and below the oxygen saturation target range, as well as the percentage of time spent in hypoxemia and hyperoxemia. <b><i>Results:</i></b> We included 9 trials (354 patients, adults and preterm infants, with or without ventilatory assistance). Eight of these trials were at high risk of bias due to lack of blinding and selective reporting. Automatic titration was associated with a significant decrease in the length of hospital stay (mean difference: –2.2 days; 95% CI: –3.8 to –0.6; <i>p</i> = 0.009; <i>I</i>² = 0%; n = 237, 2 trials), and a decrease in the length of oxygen therapy (mean difference: –1.6 days; 95% CI: –3.1 to 0.0; <i>p</i> = 0.05; <i>I</i>² = 0%; <i>n</i> = 237; 2 trials). We did not observe a reduction in the need for ventilatory assistance or in mortality in the automatic titration period. An increase in the percentage of time spent within target (mean difference: 18.23%; 95% CI: 10.93–25.52; <i>I</i>² = 81%; <i>n</i> = 351, 7 trials) and a significant reduction in the percentage of time spent in both hypoxemia and hyperoxemia with automatic compared to manual oxygen titration were, however, observed. <b><i>Conclusions:</i></b> In patients requiring supplemental oxygen in the hospital, automatic oxygen titration was associated with a reduction in length of both hospital stay and oxygen therapy, as well as a greater percentage of time spent within the saturation target range. However, it was not associated with a significant difference in the need for mechanical ventilation or in mortality. Results should be interpreted with caution due to the small number of included trials and their high risk of bias.