Ten years ago, a task force of the Society of Critical Care Medicine (SCCM) examined the onset or worsening of mental health, physical, and cognitive outcomes arising after critical illness, and coined the term “Post Intensive Care Syndrome” (PICS) to describe the phenomenon [1]. The concept was subsequently broadened to encompass the mental health status of the patient’s family (PICS-F) [2].
Before the pandemic of coronavirus disease (COVID-19) caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), approximately 19 million individuals per year developed life-threatening acute organ dysfunction secondary to sepsis necessitating admission to the intensive care unit (ICU). Among these, 14 million survive, half of these survivors recover, one third die during the year following ICU discharge, and one sixth experience permanent functional disability [3, 4], requiring partial or total help with the activities of daily living [5].
There is a paucity of literature devoted to the problem of PICS after COVID-19 [6,7,8], and no data on PICS in older survivors of severe COVID-19. Yet, to date, worldwide, more than 3 million people have been infected with COVID-19, of whom approximately 3% will require intensive care and mechanical ventilation. The length of stay in ICU and the duration of ventilator reliance are considerably longer in COVID-19, at up to 3 weeks, than in more typical ICU populations [9]. Every day, the media update the death toll, which has already exceeded 400,000 and continues to rise. Among patients requiring admission to the ICU, almost all need respiratory support, and 88% require mechanical ventilation [10]. Although roughly one-third of infected patients are over 60 years of age, more than two-thirds of deaths occur in this age group [11]. Old patients recovering from severe respiratory illness present secondary disability resulting from intensive treatments. This includes (but is not limited to) acute unit-acquired weakness, long-term cognitive impairment, and poor mental outcomes [4, 5, 12], while the patient’s family members, especially the older ones, will suffer a high psychological burden [13, 14].
Geriatricians need to be aware of these alarming data. Indeed, the COVID-19 pandemic will soon reveal the public health burden of PICS among survivors of intensive care and mechanical ventilation. There are numerous studies and reviews devoted to the management of acute COVID-19 and its immediate sequelae [12, 15,16,17]. We focus here on the involvement of multidisciplinary geriatric teams to prevent physical, cognitive and mental repercussions of COVID-19 treatment in older survivors who are discharged alive from the ICU. Geriatricians also need to anticipate the socio-psychological and economic impacts on the patient’s whole family.
Current knowledge on the long-term outcomes of PICS
The symptoms of PICS are well established, and include fatigue, muscle weakness, difficulty swallowing, cloudy thinking, difficulty concentrating, poor memory, anxiety, sadness and sleep disturbances [3, 4].
Among the physical outcomes is intensive unit-acquired muscle weakness, which results from microvascular ischemia or injury, immobility, catabolism and dysfunction of the sodium channels and mitochondria [16]. About 40% of patients suffer from polyneuropathy, neuromyopathy, or myopathy, which can result in muscle deconditioning [16]. Three months after discharge from the ICU after critical sepsis, about half of older survivors have functional recovery, and older survivors of sepsis develop 1.5 new limitations in the activities of daily living compared to 0.5 limitations in their non-ICU counterparts [13]. This may explain the greater need for community services, or the higher rates of institutionalization for rehabilitation or nursing care observed after discharge in this age group [3, 4]. Indeed, such poor physical outcomes could be aggravated by the pre-ICU health, body mass, and visual or hearing conditions.
After an ICU stay, the main cognitive impairments that persist long term are executive dysfunction, as well as memory and attention disturbances, rather than pure memory alteration. The multi-domain cognitive impairments appear to be linked to hypo- or hyperglycaemia, delirium and in-hospital acute stress [16]. The lesions observed in long-term post-ICU cognitive impairment seem to be different from those seen in Alzheimer’s disease, with smaller superior frontal lobe, thalamus and cerebellar volume associated with white matter damage [13]. In a random sample of 10,348 subjects who received intensive care and survived to discharge, during 3 years of follow-up, the incidence of newly diagnosed dementia was 15% in ICU survivors, versus 12.2% in matched controls [18]. The long-term cognitive outcomes of ICU survivors depend also on the prevalence of pre-morbid disorders and ICU-related stress. Female sex, lower education level, anxiety, pre-existing depression or post-traumatic stress disorder and alcohol abuse may all increase the risk of ICU-acquired mental illness [19]. Among adult ICU survivors, the prevalence is 19–37% for depression, 32–40% for anxiety and 19–22% for post-traumatic stress [13, 19,20,21]. Anxiety, depression and sleep disorders can last months to years, while post-traumatic stress disorder can persist for up to 8 years [5].
Current knowledge on the long-term outcomes of PICS-family
Family members of critically ill patients experience stress, anxiety, depression and complicated grief [22]. Demographic factors favoring these disorders include female gender, younger age of the patient, lower education level, being the patient’s spouse, a previous history or family history of mental health disorders [13]. There is a close relation between these predisposing factors, and ICU-related determinants, such as a perception of the patient being very near death, unexpected or sudden patient illness, family members with greater levels of anxiety and depression about the ICU hospitalization, and poor communication between family members and ICU physicians [13]. All these conditions combine to explain the rate of depression among family members of critically ill patients, which varies from 14.6 to 66.6% in the first ICU week, and may remain as high as 17.9% after 6 months. In parallel, anxiety affects between 42 and 66.6% in the first ICU week, and may persist in 15–24% at 6 months, comparable to the 6-month prevalence of post-traumatic stress disorder (33.1–49%) [16].
These long-term impairments stemming from ICU admission can cause survivors to have poor quality of life, while their families and the healthcare system, in general, also face numerous challenges that no “silver bullet” can resolve [12].