Over time, it was found that many patients maintained radiological alterations after discharge, and there were individuals who, even without lung alterations, were persistently "tired", suffered from muscular pain, shortness of breath when exercising, sleep disturbances, concentration and memory alterations, anxiety, decreased libido and often hair loss. Therefore, in the approach of these patients, in addition to studying the impact that the infection had on lung function (and if it exists, it should be treated), the possible repercussions on other systems of the human body should be assessed: cardiovascular, central nervous system, endocrine, gastrointestinal and musculoskeletal.

Post-COVID-19 sequelae are known by a variety of names (including long-term COVID or post-COVID-19 syndrome), since September 2020 they are included in the World Health Organization's international classification of diseases (WHO ICD-10) as “post-COVID-19 condition”. This inclusion was extremely important as it provides a legal response to the suffering of millions of individuals, justifying their absenteeism from work and recognizing these post-COVID-19 symptoms as a disease. In December 2021, the World Health Organization consensus definition of this post-COVID-19 syndrome was published in the journal “The Lancet Infection”: “Disease occurring in individuals with a history of probable or confirmed SARS-CoV-2 infection, usually 3 months from the onset of COVID-19 with symptoms lasting at least 2 months that cannot be explained by an alternative diagnosis”.

Persistent fatigue is the most frequent symptom, and the most complex symptom to quantify and treat. In the clinical evaluation, I initially perform a respiratory, cardiac and endocrine evaluation (COVID-19 infection can cause thyroid alterations), coordinating with functional rehabilitation through individual physiotherapy. The assessment instrument used to quantify fatigue during the medical consultation is the Chalder fatigue scale, which permits the assessment of the two domains of fatigue: physical and psychological.

Sleep alterations, especially respiratory (potentially treatable), are also evaluated, since there is a physiological justification for Obstructive Sleep Apnoea Syndrome (OSAS) to be a potential cause of post-COVID-19 fatigue.

These patients also develop frequent psychopathological alterations such as the development of symptoms of post-traumatic stress, anxiety and depression, related to the psychological pressure generated by isolation, “fear of dying” and impotence in the face of infection and eventual severity of the disease. During the medical consultation, the standardized HADS scale (Hospital Anxiety and Depression Scale) is used for an initial screening, where patients presenting high levels are referred to the appropriate specialty.

The sequelae observed after SARS-CoV-2 infection, have already been documented with relation to other viruses in the past, but the scale of the pandemic increases the number of individuals who may suffer from these symptoms, making our coordination as health professionals urgent in order to have response capacity in this new late phase of the pandemic.

Dr Lígia Pires

Specialist in Intensive Medicine and Graduate in Pulmonology

Hospital Particular in Alvor