# The Assessment of Functional Status Among COVID-19 Patients at Three Months Using Pulmonary Function Tests

## TL;DR

This study found that many patients who had moderate to severe COVID-19 still had lung issues and symptoms three months after recovery, using tests like spirometry and a six-minute walk.

## Contribution

The study introduces the use of spirometry and 6MWT to assess long-term functional limitations in post-COVID-19 patients.

## Key findings

- 80% of patients remained symptomatic three months after discharge, with exertional dyspnea being the most common symptom.
- 74% of patients walked less than expected in the six-minute walk test, with a mean distance of 426.1 meters.
- 48% of patients experienced a drop in oxygen saturation of at least 3% during the six-minute walk test.

## Abstract

Introduction

The coronavirus disease 2019 (COVID-19) pandemic has impacted the lives of thousands of patients worldwide with many patients having residual symptoms months after the acute infection. The severity of lung involvement ranges from mild asymptomatic to severe acute respiratory distress syndrome (ARDS), which may lead to pulmonary fibrosis. Pulmonary fibrosis increases the long-term morbidity of post-COVID-19 patients in the form of restrictive lung disease. The six-minute walk test (6MWT), Borg scale, and spirometry are simple and low-cost tests used to evaluate a patient's exercise capacity and functional status. This study was conducted to assess the residual symptoms and functional status using spirometry and 6MWT in COVID-19 patients of moderate to severe category after three months of discharge.

Methods

This was an observational, prospective, and cross-sectional study conducted at a tertiary care center in North India, aiming to enroll a minimum of 50 patients who recovered from COVID-19 pneumonia. These patients were previously hospitalized with moderate to severe disease severity as defined by the Indian Council of Medical Research (ICMR) criteria, and the assessment occurred at least three months after their discharge. Individuals who were under 18 years of age or pregnant or had any respiratory or cardiac illness in the past were excluded from the study.

Results

A total of 50 patients were included in the study for final analysis. After a three-month follow-up, 40 (80%) patients were still symptomatic. The most commonly reported symptom was exertional dyspnea in 21 (42%), dyspnea at rest in 16 (32%), and fatigue in three (6%) patients. Of the total patients, 37 (74%) covered a distance less than expected in the six-minute walk test. The mean distance covered by patients was 426.1 ± 115.01 m, in contrast to the expected mean distance of 537.22 ± 37.61 m according to standard equations for Indian males and females. A fall in oxygen saturation by more than or equal to 3% was observed in approximately 24 (48%) patients after the six-minute walk test. The mean value of fatigue and dyspnea score was 3.2 ± 1.7 (moderate score). Among patients with moderate disease during their hospital stay, a higher proportion exhibited a normal pattern on pulmonary function tests (PFT) compared to those severely affected, 23 (69.70%) versus two (11.76%), respectively.

Conclusion

The persistence of symptoms and functional limitation of activities should be anticipated in patients with COVID-19. Spirometry and 6MWT can be a valuable tool in determining the prevalence of functional limitation in recovered patients of COVID-19. It can potentially help in determining and further planning the rehabilitative measures in the management of COVID-19 survivors. It can also be concluded that it is important to have a long-term follow-up in patients with moderate to severe COVID-19.