Dear Editor,

Critical illness can cause new or worsened physical, mental and cognitive symptoms following intensive care unit (ICU) treatment, known as post-intensive care syndrome (PICS), which can persist for years [1]. ICU patients treated for coronavirus disease 2019 (COVID-19) frequently experience symptoms of PICS 1 year after ICU treatment; however, their long-term outcomes beyond the first year are largely unknown [2]. We therefore conducted a 2-years follow-up study to further guide ICU (after) care.

This prospective longitudinal cohort study was part of the MONITOR-IC study which was conducted in 7 Dutch hospitals [3]. All adult ICU patients admitted with COVID-19 between 1st March 2020 and 1st June 2020 who survived ICU treatment were eligible. Outcomes were measured at 1-year and 2-years follow-up using a paper or online based survey. A detailed overview of the methods is described in the electronic supplementary materials (ESM, Methods). The primary outcomes were the occurrence of physical (frail, fatigue, new physical problems), mental (anxiety, depression and post-traumatic stress disorder) and cognitive symptoms (ESM, Table 1). Secondary outcomes were Quality of Life (QoL) and work-related problems. Differences between 1-year and 2-year outcomes were examined.

In total, 292 ICU survivors were eligible and 183 were included of whom 122 (66.7%) completed the questionnaire at both time-points (ESM, Fig. 1). Their mean age was 61.5 (standard deviation [SD], 9.5) years and 28.7% were female (ESM, Table 2). Compared to 1-year follow-up, the occurrence of physical (73.8% vs. 74.4%, p = 1.00) and cognitive symptoms (14.2% vs 20.8%, p = 0.17) remained significant, and the occurrence of mental symptoms even increased (19.8% vs 29.5%, p = 0.01) after 2 years (Table 1). The most frequently experienced physical problems after 1 year, as well as after 2 years, were a weakened condition and musculoskeletal problems (ESM, Fig. 2). QoL was similar between 1-year and 2-year follow-up. At 2-year follow-up, fewer survivors experienced work-related problems compared to the 1-year follow-up (1-year: 66% vs 2-year: 32%, p = 0.04).

Table 1 Outcome scores and symptom occurrence rates in patients with COVID-19, 1 year and 2 years after ICU admission
Full size table

Our findings show that the post-ICU sequalae after ICU treatment for COVID-19 remains significant up to 2 years after treatment. In fact, most survivors do not seem to recover from their symptoms within 2 years and even experience an increase in mental symptoms. Studies exploring PICS in non-COVID-19 patients with acute distress respiratory syndrome (ARDS) reported that survivors experience persisting or newly developed symptoms beyond the first year after ICU treatment, similar to our findings in COVID-19 survivors [1, 4]. The role of COVID-19 and the pandemic in the development of PICS remain largely unclear; however, new impairments after COVID-19, often referred to as ‘long COVID’, seem to be more severe in patients treated in the ICU compared to those treated in wards only or ambulatory patients at 2-year follow-up [5]. These findings highlight the importance of prolonged follow-up after ICU treatment for COVID-19, with a more attentive approach on mental rehabilitation. We advocate for the implementation of structured, multidisciplinary, rehabilitation programs, programs for ICU patients treated for COVID-19, just as for other ICU patients, to prevent or mitigate prolonged post-ICU related impairments.