ArticlesEfficacy and economic assessment of conventional ventilatory support versus extracorporeal membrane oxygenation for severe adult respiratory failure (CESAR): a multicentre randomised controlled trial
Introduction
Despite advances in intensive care during the past 20 years, mortality and morbidity of patients with acute respiratory distress syndrome remains high; mortality for such patients is 34–58%.1, 2, 3, 4, 5, 6 Surviving patients could have clinically significant physical (respiratory and musculoskeletal) and neuropsychological (emotional and cognitive) disabilities.3 Such patients need inpatient rehabilitation and hospital readmissions, leading to high financial burden on carers and health-care systems.3
Conventional management is by intermittent positive-pressure ventilation, which can cause very high airway pressures and oxygen concentrations. The combination of barotrauma, volutrauma, biotrauma, and toxic effects of oxygen exacerbates lung injury from the primary illness. An alternative treatment, extracorporeal membrane oxygenation (ECMO), uses cardiopulmonary bypass technology to provide gas exchange so that ventilator settings can be reduced, which provides time for treatment and recovery.
Two previous randomised controlled trials have assessed adult extracorporeal life support.7, 8 Neither of these studies has relevance to modern ECMO because the case selection, ventilation strategies, extracorporeal circuit design, and disease management were completely different from modern protocols. Therefore observational studies provide the only relevant evidence. Case series of patients with severe respiratory failure report survival rates without ECMO of 18–44%6, 9 compared with up to 66% with ECMO (including full support of oxygenation and lung rest).10, 11, 12 To further define the safety, clinical efficacy, and cost-effectiveness of ECMO, we did the rigorous randomised controlled trial CESAR (Conventional ventilation or ECMO for Severe Adult Respiratory failure) in combination with an economic evaluation from the perspective of the health-care provider, the UK National Health Service (NHS).
Section snippets
Participants
Patients were enrolled from three types of centre: the ECMO centre at Glenfield Hospital, Leicester, which treated all patients who were randomly allocated for consideration to receive ECMO; tertiary intensive care units (conventional treatment centres); and referral hospitals, which sent patients to the conventional treatment centres if they were randomly allocated to receive continued conventional management.13 103 hospitals obtained ethics committee approval to collaborate in the study of
Results
Between July, 2001, and August, 2006, enquiries were made about 766 potentially eligible patients from 148 centres, of whom 180 were enrolled from 68 centres and randomly allocated (figure 1). Table 1 shows the demographic characteristics of these patients at baseline.
68 (75%) patients considered for treatment with ECMO actually had ECMO support, and most of the remaining patients (n=17) had conventional management (table 2); median duration of treatment was slightly shorter for patients
Discussion
This study shows a significant improvement in survival without severe disability at 6 months in patients transferred to a specialist centre for consideration for ECMO treatment compared with continued conventional ventilation. For patients allocated to receive conventional management, outcome at 6-month follow-up was better than predicted when planning the study. However, outcome was even better for patients allocated for consideration to receive ECMO than for those allocated to receive
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