| Summary: | <p><strong>Background</strong> Invasive mechanical ventilation (IMV) is a life-saving intervention. Following resolution of the condition that necessitated IMV, a spontaneous breathing trial (SBT) is used to determine patient readiness for IMV discontinuation. In patients who fail one or more SBTs, there is uncertainty as to the optimum management strategy.</p> <p><strong>Objective</strong> To evaluate the clinical effectiveness and cost-effectiveness of using non-invasive ventilation (NIV) as an intermediate step in the protocolised weaning of patients from IMV.</p> <p><strong>Design</strong> Pragmatic, open-label, parallel-group randomised controlled trial, with cost-effectiveness analysis.</p> <p><strong>Setting</strong> A total of 51 critical care units across the UK.</p> <p><strong>Participants</strong> Adult intensive care patients who had received IMV for at least 48 hours, who were categorised as ready to wean from ventilation, and who failed a SBT.</p> <p><strong>Interventions</strong> Control group (invasive weaning): patients continued to receive IMV with daily SBTs. A weaning protocol was used to wean pressure support based on the patient’s condition. Intervention group (non-invasive weaning): patients were extubated to NIV. A weaning protocol was used to wean inspiratory positive airway pressure, based on the patient’s condition.</p> <p><strong>Main outcome measures</strong> The primary outcome measure was time to liberation from ventilation. Secondary outcome measures included mortality, duration of IMV, proportion of patients receiving antibiotics for a presumed respiratory infection and health-related quality of life.</p> <p><strong>Results</strong> A total of 364 patients (invasive weaning, <em>n</em> = 182; non-invasive weaning, <em>n</em> = 182) were randomised. Groups were well matched at baseline. There was no difference between the invasive weaning and non-invasive weaning groups in median time to liberation from ventilation {invasive weaning 108 hours [interquartile range (IQR) 57–351 hours] vs. non-invasive weaning 104.3 hours [IQR 34.5–297 hours]; hazard ratio 1.1, 95% confidence interval [CI] 0.89 to 1.39; <em>p</em> = 0.352}. There was also no difference in mortality between groups at any time point. Patients in the non-invasive weaning group had fewer IMV days [invasive weaning 4 days (IQR 2–11 days) vs. non-invasive weaning 1 day (IQR 0–7 days); adjusted mean difference –3.1 days, 95% CI –5.75 to –0.51 days]. In addition, fewer non-invasive weaning patients required antibiotics for a respiratory infection [odds ratio (OR) 0.60, 95% CI 0.41 to 1.00; <em>p</em> = 0.048]. A higher proportion of non-invasive weaning patients required reintubation than those in the invasive weaning group (OR 2.00, 95% CI 1.27 to 3.24). The within-trial economic evaluation showed that NIV was associated with a lower net cost and a higher net effect, and was dominant in health economic terms. The probability that NIV was cost-effective was estimated at 0.58 at a cost-effectiveness threshold of £20,000 per quality-adjusted life-year.</p> <p><strong>Conclusions</strong> A protocolised non-invasive weaning strategy did not reduce time to liberation from ventilation. However, patients who underwent non-invasive weaning had fewer days requiring IMV and required fewer antibiotics for respiratory infections.</p> <p><strong>Future work</strong> In patients who fail a SBT, which factors predict an adverse outcome (reintubation, tracheostomy, death) if extubated and weaned using NIV?</p> <p><strong>Trial registration</strong> Current Controlled Trials ISRCTN15635197.</p>
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