Patients with severe forms of hypoxemic acute respiratory failure have persistent
symptoms after hospital discharge, which seem to be mediated mainly by the need for
mechanical ventilation. One of the main etiologies of hypoxemic acute respiratory failure
is still COVID-19 in its endemic form. According to the World Health Organization (WHO),
approximately 10 to 20% of people affected by COVID-19 develop persistent symptoms
(lasting more than 3 months) in a condition described as Long COVID [1]. These symptoms
can affect multiple organ systems (including respiratory, cardiovascular, musculoskeletal
and nervous systems) and health domains (physical and mental domains, for example). A
systematic review identified more than 50 symptoms potentially associated with Long
COVID, including fatigue, muscle weakness, cough, dyspnea, difficulty concentrating,
anosmia, headache, joint pain, insomnia, and anxiety were the most frequently reported.
Such findings are similar in broader populations, including those with other forms of
hypoxemic acute respiratory failure.

Observational studies demonstrate a consistent association between Long COVID and
negative impacts on functionality, quality of life, hospitalizations, and costs. Two
cohort studies conducted in the United States with COVID-19 hospitalization survivors
(whose sum totals more than 2700 participants) found 60-day rehospitalization rates
greater than 15%. Notably, about 48% of participants in one of these studies were
financially distressed by COVID-19.

Although the occurrence of prolonged post-COVID symptoms does not depend exclusively on
the severity of the initial SARS-CoV-2 infection, patients who require hospitalization
for severe acute COVID-19 are those who have a higher prevalence of Long COVID and
intensity of disabilities. In a study of more than 1700 COVID-19 survivors in China, more
severe COVID-19 cases were associated with a higher risk of persistent symptoms, reduced
physical capacity, muscle weakness, reduced ability to diffuse carbon monoxide (a test
that evaluates the oxygenation capacity of the lungs), and an impact on quality of life.
In this population of severe cases, it is believed that the prolonged effects of
SARS-CoV-2 infection are added to the physical, cognitive, and mental health sequelae
typically associated with critical illness (resulting from organ dysfunctions and
intensive treatments, for example), potentiating the impact on the long-term health of
COVID-19 survivors.

In scenarios similar to those of severe COVID-19, such as sepsis and acute respiratory
distress syndrome, the implementation of mechanical ventilation release bundles,
screening and early rehabilitation while still in the hospital ward, the adequate
transmission of continuity of care to primary care, and the provision of access to
rehabilitation after hospital discharge have shown the potential to accelerate the
recovery of people affected by sequelae related to critical illnesses. However, these
findings are based on preliminary studies that do not confirm their benefit in a large
sample and with adequate methodology. In the broadest sense, the early initiation of
interventions is an essential aspect to improve outcomes. When added to the delay in
defining the etiology of the hypoxemic acute respiratory condition, it is imperative that
the measures be applied in an equitable manner in the case of suspected COVID-19 and
maintained even if the final diagnosis is not COVID-19. It would be ethically
questionable to withdraw a potentially beneficial intervention from an at-risk population
merely because it is not COVID-19, given the immense impact of acute respiratory failure
on long-term quality of life.

Given the current scenario in Brazil, with more than 36 million people with a history of
SARS-CoV-2 infection, it is estimated that more than 1 million people have been affected
by Long COVID. Given this magnitude of cases, it is likely that during the coming years,
due to the sequelae of COVID-19, the demand on the Unified Health System (SUS) for
physical and mental rehabilitation services will increase. In this imminent situation, it
is essential to investigate effective and pragmatic strategies, such as those described
above, aimed at preventing and rehabilitating sequelae related to Long COVID, especially
in patients affected by severe forms of COVID-19. Thus, a randomized clinical trial, the
gold standard for evaluating interventions, will have the potential to support public
policies for post-COVID-19 rehabilitation with accurate and generalizable information to
the Brazilian context. The inclusion of patients with a suspected, but not confirmed,
condition will allow a greater generalization of the results and early initiation of
intervention in patients with other equally relevant pathologies with similar potential
benefits.

Therefore, we propose a process improvement implementation study, with a design based on
the allocation of hospitals (clusters) in a sequential manner (stepped wedge), to
evaluate whether the implementation of care bundles in intensive care units, wards and
post-discharge is capable of improving the quality of life in patients admitted to the
ICU with hypoxemic acute respiratory failure within 90 days after discharge hospital.