Key messages
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Compared with methods managed by clinicians, systems that automatically adapt breathing support to patient needs (automated ventilation systems) probably reduce the time spent on the breathing machine, and probably lead to a slight reduction in the time spent in intensive care and in hospital. These systems probably make little to no difference in the number of people who die, but probably reduce the need to reinsert the breathing tube (reintubation) and the need to create a hole in the front of the neck to insert the tube (tracheostomy).
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There is a need for more studies in children. Future studies should measure patient quality of life.
What are automated ventilation systems?
Many critically ill people need assistance from a breathing machine (ventilator). Reducing the level of breathing support and transitioning the patient to normal breathing (a process called weaning) requires both expertise and continuous monitoring. If weaning methods are not optimal, patients may spend too long on the ventilator, putting them at risk of lung injury, pneumonia, and death. At times, organizational constraints prevent delivery of the most effective and efficient care. Automated ventilation systems may provide a solution to this problem. These systems monitor the patient continually and adjust the level of breathing support without a member of the clinical team having to intervene.
What did we want to find out?
We wanted to know if automated ventilation systems were better than management of weaning by clinicians for reducing:
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the duration of mechanical ventilation;
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death;
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the length of intensive care unit and hospital stays;
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unwanted events linked to being on a ventilator, such as the need to reinsert the breathing tube (reintubation) or the need to create a hole in the front of the neck to insert the tube (tracheostomy); and
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patient quality of life.
What did we do?
We looked for studies that compared automated ventilation systems with clinical weaning methods in adults and children. We compared and summarized the results and rated our confidence in the evidence based on factors such as study methods and sizes.
What did we find?
We found 62 studies that included 5052 people (4834 adults and 218 children). Reasons people needed to be on a ventilator were that they had pneumonia or another infection, they were seriously injured, or they had undergone surgery. The studies evaluated several commercially available automated ventilation systems.
Main results
Compared with clinical weaning methods, automated weaning systems:
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probably reduce the time on the ventilator by around 24%, or 1.7 days in adults and 16 hours in children;
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probably have little to no effect on the number of people who die;
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probably reduce the length of stay in the intensive care unit by around 14%, or 1.3 days in adults and 0.6 days in children;
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probably reduce the length of stay in hospital by around 10%, or 2 days in adults and 0.9 days in children;
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probably reduce the need for reintubation; and
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probably reduce the need for tracheostomy.
No studies reported health-related quality of life.
What are the limitations of the evidence?
Our confidence in the evidence is only moderate because the studies were done in different types of people or used different ways of delivering automated weaning (for the outcomes duration of mechanical ventilation, length of stay in the intensive care unit, and length of hospital stay), or because there were not enough studies to be certain about the results of our outcomes (unwanted events).
How up to date is this evidence?
This review updates our previous review. The evidence is current to 2 January 2024.
Baca abstrak penuh
Automated closed loop systems may improve adaptation of mechanical support for a patient's ventilatory needs and facilitate systematic and early recognition of their ability to breathe spontaneously and the potential for discontinuation of ventilation. This review was originally published in 2013 with an update published in 2014.
Matlamat
To evaluate the benefits and harms of automated weaning systems compared with non-automated weaning methods in critically ill, mechanically ventilated adults and children.
Kaedah Pencarian
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.
Kriteria Pemilihan
We included randomized controlled trials comparing automated closed loop ventilator applications to non-automated weaning strategies including non-protocolized usual care and protocolized weaning in patients over four weeks of age receiving invasive mechanical ventilation in an ICU.
Pengumpulan Data dan Analisis
Two authors independently extracted study data and assessed risk of bias. We combined data in forest plots using random-effects modelling. Subgroup and sensitivity analyses were conducted according to a priori criteria.
Keputusan Utama
We included 21 trials (19 adult, two paediatric) totaling 1676 participants (1628 adults, 48 children) in this updated review. Pooled data from 16 eligible trials reporting weaning duration indicated that automated closed loop systems reduced the geometric mean duration of weaning by 30% (95% confidence interval (CI) 13% to 45%), however heterogeneity was substantial (I2 = 87%, P < 0.00001). Reduced weaning duration was found with mixed or medical ICU populations (42%, 95% CI 10% to 63%) and Smartcare/PS™ (28%, 95% CI 7% to 49%) but not in surgical populations or using other systems. Automated closed loop systems reduced the duration of ventilation (10%, 95% CI 3% to 16%) and ICU LOS (8%, 95% CI 0% to 15%). There was no strong evidence of an effect on mortality rates, hospital LOS, reintubation rates, self-extubation and use of non-invasive ventilation following extubation. Prolonged mechanical ventilation > 21 days and tracheostomy were reduced in favour of automated systems (relative risk (RR) 0.51, 95% CI 0.27 to 0.95 and RR 0.67, 95% CI 0.50 to 0.90 respectively). Overall the quality of the evidence was high with the majority of trials rated as low risk.
Kesimpulan Pengarang
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).