Eligible patients who have been treated in the intensive care units of Helsinki University Hospital are invited to participate. Controls are recruited from follow-up clinics, and with announcements in media and websites.~The participants receive an invitation to a follow-up clinic where their experiences from the ICU treatment and recovery will be discussed. The investigators will perform neuropsychologic testing (6 months post-discharge), a telephone interview (3 months) and send written questionnaires (3, 6 and 24 months) to the participants. The participants will undergo MRI imaging of the brain and laboratory tests will be taken. The olfactory function will be tested at a follow-up clinic. Data on the patients´ respiratory function from clinical spirometry and diffusion capacity testing 3 and 6 months after discharge are collected. The patients will perform a 6 min walk test.~Data on coagulation laboratory values will be registered from acute phase and 6 months after discharge. The investigators will also analyse ApoE alleles, neurofilament light and NAD-metabolites and study their correlation with neuropsychologic findings and long term symptoms (up to 5 years after hospital discharge).~Participants will also undergo magnetic resonance imaging of the heart at 6-12 months after the hospital discharge, and laboratory samples, a symptom questionnaire and electrocardiogram are collected. Inflammatory parameters and variables associated with regulating inflammation and coagulation will be analysed.~Clinical data from the acute and post-acute phase and demographic data are collected from the patient data management systems.~The target patient number is 75 intensive care treated patients and 50 control persons in each three control group.
The study focuses on the recovery of respiratory, cardiovascular and neurological/neuropsychological recovery after intensive care treatment for covid-19. The results will be compared with those obtained from patients treated in the regular wards for covid-19, persons with home treated covid-19 and non-covid controls.