Automated versus non-automated weaning for reducing the duration of mechanical ventilation for critically ill adults and children.

Rationale: Automated closed-loop systems may improve the adaptation of mechanical ventilatory support to an individual's ventilatory needs. They may also facilitate systematic and early recognition of the patient's ability to breathe spontaneously and come off the ventilator. This is an update of a Cochrane review originally published in 2013 and last updated in 2014.

Objectives: To evaluate the benefits and harms of automated weaning systems compared with non-automated weaning methods in critically ill, mechanically ventilated adults and children.

Search methods: We searched MEDLINE ALL, Embase Classic+Embase, the Cochrane Library (Wiley), CINAHL (EBSCO), the Web of Science Core Collection, and trial registries on 2 February 2024. We checked the reference lists of included studies and relevant systematic reviews for other potentially eligible studies.

Eligibility criteria: We included randomized controlled trials (RCTs) evaluating automated closed-loop ventilator applications versus non-automated weaning methods (including non-protocolized usual care and protocolized weaning) in people aged over four weeks who were receiving invasive mechanical ventilation in an intensive care unit (ICU).

Outcomes: Our critical outcomes were duration of mechanical ventilation (from randomization to successful unassisted breathing or death), mortality, ICU length of stay, and hospital length of stay. Our important outcomes included other ventilation durations, adverse events related to mechanical ventilation, and health-related quality of life.

Risk of bias: Two review authors independently assessed risk of bias using the Cochrane risk of bias tool RoB 1.

Synthesis methods: Two review authors independently extracted study data. We synthesized results for each outcome using meta-analysis (random-effects modeling). Subgroup and sensitivity analyses were conducted according to pre-established criteria. We used GRADE to assess the certainty of evidence for each outcome.

Included studies: This update included 62 trials (59 in adults, 3 in children) with 5052 participants (4834 adults, 218 children). The trials evaluated 10 commercially available automated closed-loop systems and one non-commercial system. Forty trials were conducted in mixed or medical ICU populations, the remainder in surgical ICU populations.

Synthesis of results: Automated closed-loop systems probably reduce the duration of mechanical ventilation compared with non-automated weaning methods (mean difference [MD] -0.28 log hours, 95% confidence interval [CI] -0.36 to -0.20; I² = 87%; 51 RCTs, 3929 participants; moderate-certainty evidence). These data translate to a relative reduction of 24% (95% CI 18% to 30%). Automated closed-loop systems probably result in little to no difference in mortality compared with non-automated weaning methods (risk ratio [RR] 0.94, 95% CI 0.82 to 1.07; I² = 0%; 38 RCTs, 3620 participants, 618 events; moderate-certainty evidence). Automated closed-loop systems probably reduce ICU length of stay compared with non-automated weaning methods (MD -0.15 log days, 95% CI -0.20 to -0.09; I² = 71%; 40 RCTs, 3571 participants; moderate-certainty evidence). These data translate to a relative reduction of 14% (95% CI 9% to 18%). Automated closed-loop systems probably reduce hospital length of stay compared with non-automated weaning methods (MD -0.11 log days, 95% CI -0.16 to -0.05; I² = 43%; 26 RCTs, 2094 participants; moderate-certainty evidence). These data translate to a relative reduction of 10% (95% CI 5% to 15%). In relation to adverse events related to mechanical ventilation, automated closed-loop systems compared with non-automated weaning methods probably reduce the need for reintubation (RR 0.73, 95% CI 0.59 to 0.89; I² = 0%; 28 RCTs, 2670 participants; moderate-certainty evidence), non-invasive ventilation following extubation (RR 0.74, 95% CI 0.62 to 0.88, I² = 0%; 23 RCTs, 2451 participants; moderate-certainty evidence), prolonged ventilation (RR 0.54, 95% CI 0.34 to 0.87; I² = 0%; 11 RCTs, 1191 participants; moderate-certainty evidence), and tracheostomy (RR 0.75, 95% CI 0.62 to 0.91; I² = 0%; 17 RCTs, 1857 participants; moderate-certainty evidence). No studies reported health-related quality of life. Evidence certainty was downgraded for heterogeneity or imprecision.

Authors' conclusions: Based on moderate-certainty evidence from 62 trials including over 5000 critically ill people (mainly adults), we found that automated closed-loop systems probably reduce the duration of mechanical ventilation and the length of ICU and hospital stay compared with non-automated weaning methods. Automated systems probably have little to no effect on mortality but probably reduce the need for reintubation, non-invasive ventilation, prolonged ventilation, and tracheostomy. Given the moderate-certainty evidence of benefit and no evidence of harm, the adoption of automated closed-loop ventilation systems into adult critical care clinical practice warrants consideration. There is a need for further adequately powered multi-center trials in adults and children. Future trials should include health-related quality of life among their outcomes.

Funding: This review received no funding.

Registration: The original review was registered with the Cochrane Database of Systematic Reviews, registration number CD009235. The original protocol, published in 2011, is available at DOI: 10.1002/14651858.CD009235. Previous versions of the review are available at DOI: 10.1002/14651858.CD009235.pub2 (2013) and DOI: 10.1002/14651858.CD009235.pub3 (2014).