ASSESSMENT OF EXERCISE CAPACITY IN INDIVIDUALS HOSPITALIZED FOR COVID-19: COMPARISON BETWEEN 30 DAYS AND 12 MONTHS AFTER HOSPITAL DISCHARGE

Background

The 6-Minute Step Test (6MST) has been used to evaluate exercise capacity and physiological responses during the test in different populations, to assess physical performance for the activity of stepping up and down a step, as well as check for possible symptoms that the individual may present during the test. The use of 6MST to evaluate the exercise capacity of individuals who were hospitalized for COVID-19 can identify the persistence of symptoms and exercise intolerance.

Objectives

To compare the exercise capacity and physiological responses of individuals hospitalized for COVID-19 using the 6MST, at 30 days and 12 months after hospital discharge.

Methods

A longitudinal study was conducted with individuals hospitalized for COVID-19 and evaluated at two-time points: 30 days after hospital discharge and 12 months after hospital discharge. The 6MST was applied with monitoring of vital signs (blood pressure - BP, heart rate - HR, and peripheral oxygen saturation - SpO2) and recording of perceived pain/fatigue in the lower limbs and respiratory fatigue. At the end of the test, the number of steps executed was recorded to establish the individual's exercise capacity and to identify the percentage of the number of steps achieved according to predicted values for sex, age, height, and weight.

Results

Twenty-three individuals were evaluated, and a significant difference was found in the 6MST performance (p≤0.05), with a higher number of steps recorded in the evaluation after 12 months of hospital discharge in 82.6% of individuals. Regarding vital signs, there was a statistically significant difference (p≤0.05) in SpO2 at the peak of the 6MST, with better saturation in the evaluation performed after 12 months of hospital discharge. There was a moderate positive correlation (R=0.420, p≤0.046) between a worse 6MST performance (evaluated by the number of steps) in individuals who required intensive care. There was no statistically significant difference (p≤0.05) in HR and SpO2 at the peak of the test and in the first minute of recovery.

Conclusion

The exercise capacity verified by the 6MST performance in individuals who were hospitalized and received intensive care due to COVID-19 is significantly lower in the first days after hospital discharge, compared to a period of 12 months after discharge. The 6MST performance was better after 12 months of hospital discharge, indicating improvement in exercise tolerance in 82.6% of individuals. The mean SpO2 measured at the peak of the 6MST was lower in the evaluation at 30 days compared to the assessment at 12 months after hospital discharge. It may be related to lower exercise capacity in individuals affected by COVID-19.

Implications

It is necessary to monitor these individuals affected by COVID-19, and when indicated, they should be included in a pulmonary rehabilitation program with individualized physical training prescription, promoting improvement in exercise capacity and reduction of persistent symptoms.