Impact of COVID infection on lung function test and quality of life

Functional Capacity Impairment in Long COVID After 17 Months of Severe Acute Disease

Long COVID represents a significant challenge in understanding the prolonged impact of the disease. Despite its increasing recognition, detailed insights into the long-term cardiopulmonary consequences remain sparse. This study aimed to evaluate the functional capacity of individuals with persistent symptoms after severe COVID-19 infection compared to control individuals without symptomatic COVID or mild COVID after 17 months. This is a case-control study assessing 34 individuals divided into two groups regarding functional capacity by distance in a 6-min walk test (D6MWT) associated with gas analysis, spirometry, respiratory muscle strength, and quality of life. During the 6 MWT, an important lower heart rate (HR) was observed for the COVID group (106 ± 10 bpm, difference mean: 21.3; p < 0.001), with greater exertional perception (Borg dyspnea: 4.5 [2.0-9.0], p < 0.001 and Borg fatigue: 4.0 [2.0-7.0], p = 0.01), a significant decrease in the distance covered (416 ± 94 m, difference mean: 107; p = 0.002), and a low value of O2 uptake (V˙O2) (11 ± 5.0 mL/(kg min), difference mean: 8.3; p = 0.005) and minute ventilation (22 ± 8 L/min, difference mean: 18.6; p = 0.002), in addition to very low quality of life scores. Regression analysis showed a significant association between D6MWT and Borg fatigue and Borg dyspnea at rest (p = 0.003; p = 0.009). V˙O2 and HR were also significantly associated with the outcomes of the D6MWT (p = 0.04 and p = 0.004, respectively). In conclusion, individuals who have severe COVID-19 and persist with symptoms have low functional capacity, low V˙O2, low HR behavior, and low quality of life.

Assessing post-COVID-19 respiratory dynamics: a comprehensive analysis of pulmonary function, bronchial hyperresponsiveness and bronchodilator response

Background

Coronavirus disease 2019 (COVID-19) has a considerable impact on the global healthcare system. Individuals who have recovered from COVID often experience chronic respiratory symptoms that affect their daily lives. This study aimed to assess respiratory dynamics such as airway hyperresponsiveness (AHR) and bronchodilator response in post-COVID patients.

Methods

This study included 282 adults with respiratory symptoms who underwent provocation tests. The demographic details, clinical symptoms and medical histories were recorded. Baseline spirometry, methacholine challenge tests (MCT) and post-bronchodilator spirometry were performed. Patients were divided into the following four groups: Group 1: non-COVID-19 and negative MCT; Group 2: post-COVID-19 and negative MCT; Group 3: non-COVID-19 and positive MCT; and Group 4: post-COVID-19 and positive MCT.

Results

Most post-COVID-19 patients (43.7%) experienced AHR, and wheezing was more common. Patients in Group 4 exhibited increased intensities of dyspnoea, cough and wheezing with the lowest pulmonary function test (PFT) parameters at baseline. Moreover, significant decreases in PFT parameters after the MCT were observed in these patients. Although the prevalence of a low forced expiratory volume in 1 s to forced vital capacity ratio (<70%) was initially 2% in Group 4, it increased to 29% after MCT. No significant differences in allergic history or underlying diseases were observed between the groups.

Conclusions

These findings provide comprehensive insights into the AHR and respiratory symptoms of post-COVID-19 individuals, highlighting the characteristics and potential exacerbations in patients with positive MCT results. This emphasises the need of MCT to address respiratory dynamics in post-COVID-19 individuals.

Looking at the Data on Smoking and Post-COVID-19 Syndrome-A Literature Review

Long COVID is a recently described entity that is responsible for significant morbidity and that has consequences ranging from mild to life-threatening. The underlying mechanisms are not completely understood, and treatment options are currently limited, as existing data focus more on risk factors and predictors. Smoking has been reported as a risk factor for poor outcomes of acute SARS-CoV-2 infection and seems to also play a role in mediating post-COVID-19 symptoms. We aimed to review relevant work addressing the interaction between smoking and long COVID in order to characterize smoking's role as a risk factor and possibly identify new research directions. Methods: The PubMed/MEDLINE database was searched using the keywords 'smoking', 'long COVID', and 'post-acute COVID' to identify relevant English-language articles published up to October 2023. Results and conclusions: From the 374 initial hits, a total of 36 papers were deemed relevant to the aim of the review. There was significant variability concerning the ways in which tobacco usage was quantified and reported; still, there is compelling evidence linking smoking to an increased risk of developing manifestations of post-acute-COVID disease. Some clinical conditions, such as dyspnea, cardiovascular symptoms, and cognitive or mental-health impairment, seem to be relatively strongly associated with smoking, while the connection between smoking and upper-airway involvement seems less certain. The available data support recommending smoking cessation as a clinical tool for the prevention of long COVID.