Follow-up after treatment with Extracorporeal Membrane Oxygenation (ECMO) at the ECMO Center Karolinska.

Patients: adult survivors treated with ECMO for severe refractory respiratory failure at least 5 years earlier.

Investigations: brain and pulmonary radiographic morphology, cognitive testing, pulmonary function testing, exercise tolerance, quality of life and mood disorder screening.

All adult patients treated at the ECMO Center Karolinska between 1995 and July 2009 were screened for eligibility in January 2014. Patients living abroad (including non-Swedish citizens), patients treated for non-respiratory conditions, diseased patients and patients with a known pre-ECMO mental handicap were excluded.

Eligible patients were contacted, and patients who agreed to participate gave their written informed consent. All studied patients underwent the same study protocol during a day at the hospital, including a clinical interview, MRI scan of the brain, HRCT scan of the thorax, pulmonary function testing, neuropsychological examination, walking test, self assessment questionnaires for quality of life, anxiety, depression and post-traumatic stress.

Patient charts were reviewed for relevant clinical information, including age, gender, ECMO mode (venovenous or venoarterial), time in hospital, on ECMO, non-ECMO ICU and on mechanical ventilation; preexisting diseases, blood gas values and ventilator settings before initiation of ECMO treatment. Hand written clinical data from the patients´ charts from every hour with ECMO treatment was reviewed for ventilator settings, lung volumes, mean arterial pressure, hemoglobin, lactate and oxygenation parameters during an observation period, which was defined as the first 10 days on ECMO (or the entire treatment period if shorter than 10 days). This information was added to a digital database for the purpose of this study.

At the time of ECMO treatment, arterial hemoglobin oxygen saturation was measured by peripheral pulse oximetry from the right ear, finger or nose. Venous preoxygenator lactate and venous saturation values were used as indicators of sufficient (lactate < 2 mmol l-1 , SvO2 ≥ 70%) or insufficient tissue perfusion.

Inclusion Criteria:

• Adult patients treated with ECMO at the ECMO Center Karolinska 1995 - July 2009

Exclusion Criteria:

• Diseased patients
• Patients living abroad (including non-Swedish citizens)
• Patients treated for non-respiratory conditions
• Patients with a known pre-ECMO mental handicap

All investigators (radiologist, neuropsychologist, physiotherapist) were masked from all patient details other than the fact that they were treated with ECMO (ie did not know when the patient was treated, for what condition, if any side effects were seen and so on).