ABSTRACT
PURPOSE/HYPOTHESIS: Some patients with COVID-19 have physical impairments that last well beyond the acute infection, termed long-COVID. An increasing number of patients experiencing ongoing symptoms are being referred to outpatient Pulmonary Rehabilitation (PR) with a growing understanding of their key limitations and the benefits of PR. Patients with long- COVID often present with significant inspiratory muscle weakness and functional limitations even months after infection and benefit from PR and IMT. The purpose of this study was to examine the impact of PR on inspiratory muscle performance (IMP) and several functional performance measures (FPM), as well as COPD Assessment Tool (CAT), quality of life (QOL) and depression (D) screening. NUMBER OF SUBJECTS: Eight patients (3 male and 5 female, age 51 +/- 15, BMI 32 +/- 6) diagnosed with long- COVID-19. MATERIALS AND METHODS: Twenty-two patients with long-COVID entered PR but only 8 patients successfully completed the program. The PR program included aerobic exercise, strength training, IMT, and education. Of the 22 patients who started PR, 64% dropped out due to a variety of reasons. IMP was examined via the PrO2 from residual volume providing the maximal inspiratory pressure (MIP) at 1 to 2 seconds of inspiration and the sustained maximal inspiratory pressure (SMIP) from MIP to total lung capacity. The 6-minute walk test (6MWT), timed-up-and-go (TUG), BERG balance test (BERG), 5x-sit-to-stand (5xSS), Patient Health Questionnaire (PHQ9), Ferrans & Powers QOL, and CAT were measured using standardized methods. Wilcoxon Signed Rank Tests were computed before and after PR with statistical significance set at P< 05. RESULT(S): No significant difference in any outcome measure was found when comparing completers to non-completers of PR. Significant (P< 05) improvements in the SMIP (198.1 +/- 61.5-286.8 +/- 130.7 PTU), 6MWT (313 +/- 103-451 +/- 101 m), TUG (7.7 +/- 2.3-6.2 +/- 1.1 s), 5xSS (13.0 +/- 3.2-10.5 +/- 1.5 s) and QOL (21.2 +/- 3.6-24.8 +/- 2.4) were observed, while non-significant changes were observed in PHQ9 (7.3 +/- 5.6-6.5 +/- 5.1), BERG (52.7 +/- 6.7-55.8 +/- 0.4), MIP (69.9 +/- 17.2-84.8 +/- 27.7 cmH2O), and CAT (22.2 +/- 7.7-19.8 +/- 7.9) following PR. At baseline, SMIP but not MIP was significantly (P< 05) lower than predicted values (41 +/- 11% and 76 +/- 20%) but following PR the difference from predicted was no longer significant. CONCLUSION(S): Only 36% of patients with long-COVID who were referred to and initiated PR successfully completed the program. Following PR, patients demonstrated significant improvements in inspiratory muscle endurance, functional performance, and self-reported QOL, with non-significant improvements in balance and self-reported symptoms, confidence with activity, and depression. CLINICAL RELEVANCE: IMP and FPM are significantly impaired in patients with long-COVID. PR has been shown to significantly improve many respiratory, functional performance, and psychosocial outcome measures and should be considered as part of the plan of care for these patients. Furthermore, methods to improve adherence to PR in patients with long-COVID are needed.
ABSTRACT
PURPOSE/HYPOTHESIS: Literature has reported some patients experience long-term impairments in pulmonary function following COVID-19 infection, with the most common abnormality being diffusing capacity for carbon monoxide (DLCO). Research on DLCO's association with other measures has been varied, with some studies demonstrating a significant association with older age, female gender, and disease severity, however these results are not consistent. In pulmonary patients, a DLCO of<40% or a drop in DLCO of >4 units is associated with increased morbidity and mortality, is an independent predictor of decreased exercise capacity, and predicts a more rapid decline in pulmonary function. In COPD patients, every 10% decrease in DLCO was associated with worsening quality of life (QOL), 6MWT, severe exacerbations, symptoms, and COPD assessment test (CAT) scores. CAT scores represent the general health status and include cough, sputum, energy, and ability to perform physical work. Daynes et al found an average of 52% of COVID-19 patients had high CAT scores (>10), which the GOLD guidelines suggest using as a cutoff to indicate symptomatic COPD. They found no significant association between CAT score and hospital length of stay or days on mechanical ventilation, but did find a moderately significant association to anxiety, depression, and self-reported physical activity levels.While a patient's pulmonary function test (PFT) may not be available to a clinician, the CAT is a quick and easy screening tool that can be performed in the clinic. The purpose of this study was to assess possible relationships between PFT measures and outcome assessments that can be performed in the clinic by a physical therapist (PT), which may aid in prognosis. NUMBER OF SUBJECTS: Sixteen subjects (8 male and 8 female with a mean age and BMI of 52 +/- 16 and 32 +/- 5, respectively) diagnosed with long-COVID and referred to pulmonary rehabilitation (PR). MATERIALS AND METHODS: Baseline PFT and CAT scores were obtained during the initial evaluation. Spearman's rho correlation analyses were performed. The 6MWT and DLCO were performed using standardized methods. RESULT(S): The baseline CAT, DLCO, and 6MWT were 22.2 +/- 6.7, 14.1 +/- 7.3 and 292 +/- 144 m, respectively. The CAT was significantly correlated to the DLCO (r-value of -0.63;P = .009) and 6MWT (r-value of -0.52;P = .04). CONCLUSION(S): Self-reported CAT scores were significantly correlated with DLCO and 6MWT in patients with long-COVID. CLINICAL RELEVANCE: DLCO is the most common PFT abnormality observed in patients with long- COVID and can provide useful information to the clinician regarding prognosis and possibly disease severity. However, PTs may not have access to a patient's PFT report. Alternatively, a CAT assessment is free and quick and can be easily performed in the clinic.We found CAT scores were significantly correlated to DLCO and 6MWT, which may allow clinicians to use CAT scores as a surrogate measure to aid in establishing a prognosis and/or understanding of disease severity in patients with long-COVID.