Does ECMO increase 6-month survivability without severe disability in patients with severe but reversible respiratory failure compared to conventional ventilator management? Is ECMO cost-effective compared to conventional ventilator support?
ECMO is cost effective and does increase survival without severe disability at 6 months in patients with severe reversible respiratory failure compared to conventional management in the UK.
The previous trials regarding ECMO use were performed with outdated protocols. The CESAR trial was designed with current ECMO protocols to determine the benefit of ECMO in terms of survival without disability at 6 months compared to conventional therapy in patients with severe respiratory failure. They have shown that referral for ECMO is associated with increased survival without severe disability at 6 months and is economically reasonable in the United Kingdom.
- Randomized control trial
- ECMO (n=90)
- Conventional Management (n=90)
- Setting: 92 Conventional Treatment Centers, 11 Referal Hospitals and 1 ECMO center in the UK. If included in the trial participants were transferred to either a conventional treatment center or to the ECMO center.
- Enrollment: July 2001 to August 2006
- Mean follow-up: 6 months
- Analysis: Intention-to-treat
- Primary outcome: Death or severe disability at 6 months
- Adults 18-65
- Severe respiratory failure with Murray Score >/=3.0 or uncompensated hypercapnea with pH<7.20
- >7 days of prior high pressure (>30cm H2O) or high FiO2 (>0.80) ventilation
- Contraindication to heparin including intra-cranial bleed
- Moribund patients as determined by ECMO consultant
- Any other contra-indication to continued treatment
- Mean age: 40
- Percent male: 58
- Primary diagnosis: Pneumonia 61%, other ARDS 29%
- Mean hours of positive pressure ventilation at entry: 36
- Mean hours of high-pressure ventilation or high FiO2 at entry: 28
- APACHE II score: 19
- Mean Murray score: 3.5
- 180 eligible patients were randomized into ECMO(n=90) or conventional ventilator management(n=90)
- If assigned to ECMO or conventional management and at a referral hospital or conventional management center, patients were transported to either a conventional management center or to the ECMO center
- The 90 patients assigned to conventional management all received conventional management
- 22 patients randomized to ECMO did not receive ECMO because they improved with conventional management (n=16, died prior to transfer (n=3) or during transfer (n=2), or had a contra-indication to heparin (n=1)
- ECMO protocol was veno-venous via cannulation of the femoral or right jugular veins. Normothermia was maintained, ventilator settings were reduced gradually to allow lung rest, anticoagulation was maintained with heparin, patients were fed parenterally or enterally, hemofiltration was provided as needed, Hgb concentration was maintained at 14g/dl and platelets at >100,000, and if liver failure developed patients were supported with the Molecular Absorbent Recirculating System. ECMO was weaned when chest Xray showed improvement, lung compliance improved and the patient was ventilating well while ECMO was turned off.
- Conventional management included all conventional management means at the discretion of the treating intensivists. They were recommended to use a low ventilation strategy (TV 4-8 ml/kg).
- At six months all participants were screened with SF-36, EQ-5D, St Georges hospital respiratory questionnaire, hospital anxiety and depression scale and the mini-mental status examination tools. Spirometry was also used to assess pulmonary function.
Comparisons are assignment to ECMO vs conventional management.
- Survival without severe disability (not being able to wash or dress alone) at 6 months
- 63% vs. 47% (RR 0.69; 95% CI 0.5-0.97; P=0.03)
- Duration of stay in intensive care
- 24 days vs. 13 days
- Duration of stay in the hospital
- 35 days vs. 17 days
- One patient died during transfer to ECMO center secondary to mechanical failure of the ambulance oxygen supply.
- One patient had a vessel perforated during ECMO cannulation and this was considered contributory to his ultimate demise.
UK NHS Health Technology Assessment, English National Specialist Commissioning Advisory Group, Scottish Department of Health, and the Welsh Department of Health