Inspiratory muscle strength and function in mechanically ventilated COVID-19 survivors 3 and 6 months after intensive care unit discharge

Insomnia, cardiorespiratory function and quality of life in individuals with post-COVID-19 fatigue

Objective

This study aimed to compare the prevalence of insomnia, lung function, inspiratory muscle function, functional capacity, and quality of life in individuals with and without post-COVID-19 fatigue.

Methods

Thirty-four post-COVID-19 individuals participated in the study, 20 with fatigue (32 ± 12 years old, 15% male) and 14 without fatigue (31 ± 12 years old, 42.9% male). The Chalder Fatigue Scale (CFS) was employed to categorize the volunteers into two groups: those with fatigue (score ≥4) and those without fatigue (score <4). The Insomnia Severity Index (ISI) and the Epworth Sleepiness Scale (ESS) were used to assess insomnia and excessive daytime sleepiness, respectively. Pulmonary function was evaluated by spirometry, inspiratory muscle strength was assessed by the maximum inspiratory pressure (MIP), and inspiratory endurance was evaluated by maintaining an inspiratory load of 60% of MIP until fatigue. The 6-min walk test (6MWT) was used to evaluated functional capacity, while the WHOQOL-BREF questionnaire assessed quality of life.

Results

Individuals with post-COVID-19 fatigue demonstrated a higher prevalence of insomnia (80% vs. 49%) and excessive daytime sleepiness (45% vs. 7%), as well as lower MIP, shorter distance covered in the 6MWT, and lower FEV1/FVC (forced expired volume in the first second divided by forced vital capacity), and FEV1/FVC% of predicted. Additionally, they exhibited poorer quality of life in the physical and environmental domains. CFS demonstrated a direct correlation with ISI (r=0.436, p=0.01) and ESS (r=0.593, p=0.001), as well as an inverse correlation with the distance covered in the 6MWT (r=-0.398, p=0.022) and FEV1 (r=-0.412, p=0.01). ISI was an independent predictor of CFS, with 62% of CFS variance explained by ISI variance.

Conclusion

Individuals with symptoms of post-COVID-19 fatigue may have a higher prevalence of insomnia, reduced inspiratory muscle strength, functional capacity, and Tiffeneau index, along with impaired quality of life. ISI is an independent predictor of post-COVID-19 fatigue.

Outcome Measures to Evaluate Functional Recovery in Survivors of Respiratory Failure: A Scoping Review

BACKGROUND

Respiratory failure is a life-threatening condition affecting millions of individuals in the United States annually. Survivors experience persistent functional impairments, decreased quality of life, and cognitive impairments. However, no established standard exists for measuring functional recovery among survivors of respiratory failure.

RESEARCH QUESTION

What outcomes are being used to measure and characterize functional recovery among survivors of respiratory failure?

STUDY DESIGN AND METHODS

In this scoping review, we developed a review protocol following International Prospective Register of Systematic Reviews (PROSPERO) guidelines. Two independent reviewers assessed titles and abstracts, followed by full-text review. Articles were included if study participants were aged 18 years or older, survived a hospitalization for acute respiratory failure, and received invasive mechanical ventilation as an intervention; identified function or functional recovery after respiratory failure as a study outcome; were peer-reviewed; and used any type of quantitative study design.

RESULTS

We reviewed 5,873 abstracts and identified 56 eligible articles. Among these articles, 28 distinct measures were used to assess functional recovery among survivors, including both performance-based measures (n = 8) and self-reported and proxy-reported measures (n = 20). Before 2019, 12 of the 28 distinct outcome measures (43%) were used, whereas 25 distinct measures (89%) were used from 2019 through 2024. The 6-min walk test appeared most frequently (46%) across the studies, and only 34 of 56 studies measured outcomes ≥ 6 months after discharge or study enrollment.

INTERPRETATION

Heterogeneity exists in how functional recovery is measured among survivors of respiratory failure, which highlights a need to establish a gold standard to ensure effective and consistent measurement. CHEST Critical Care 2024; 2(3):100084.

Residual radiological opacities correlate with disease outcomes in ICU-treated COVID-19

Background

Few studies consider both radiological and functional outcomes in COVID-19 survivors treated in the intensive care unit (ICU). We investigated clinical findings and pulmonary abnormalities on chest computed tomography (CT) and compared outcomes of severe versus mild-moderate acute respiratory distress syndrome (ARDS) on long-term follow-up.

Methods

This longitudinal cohort study included 118 COVID-19 patients (median age, 58 years; 79% men). Thoracic CT scans were performed 4, 10, and 22 months after hospital discharge. Two independent blinded radiologists analyzed the 10 months scans and scored the radiology findings semi-quantitatively, as no/minor versus widespread opacities [low-radiology opacity grade (ROG) versus high-ROG]. ARDS severity was based on the PaO2/FiO2 ratio. The 6 min walk test (6MWT) was performed after 3 and 9 months, and lung diffusion capacity for carbon monoxide (DLCO) and lung volume measurement after 9 and 15 months. Dynamic spirometry was done at all time points. Residual symptoms and health-related quality-of-life (HRQL) were evaluated using validated questionnaires.

Results

At 10 months, most patients (81/118; 69%) were classified as high-ROG, of which 70% had severe ARDS during hospitalisation; 69% of those with mild-moderate ARDS also had high-ROG. Patients with high-ROG had longer ICU stay and lower PaO2/FiO2 during hospitalisation (p < 0.01). At 9 months follow-up, patients with high-ROG had smaller lung volumes as % of predicted values [mean (±CI): 80 (77-84) vs. 93 (88-98) (p < 0.001)], lower DLCO as % of predicted values [74 (70-78) vs. 87 (82-92) (p < 0.001)], lower oxygen saturation during 6MWT (p = 0.02), and a tendency to more severe dyspnoea (p = 0.07), but no difference was found in HRQL compared with no/minor ROG (p = 0.92). A higher opacity score was related to lower DLCO at follow-up (r = -0.48, p < 0.001, Spearman rank test). Severe ARDS patients had slightly more severe fatigue at 9 months compared to mild-moderate, but no differences in dyspnoea or lung function at follow-up. Fibrotic-like changes were found in 93% of patients examined with CT scans at 2 years (55/118; 47%). Severe ARDS could predict widespread opacities (ROG > 25%) in most patients at follow-up at 10 months (AUC 0.74).

Conclusion

Residual radiological abnormalities in ICU-treated COVID-19 patients, evaluated for up to 2 years, relate to persisting symptoms and impaired lung function, demanding careful follow-up regardless of ARDS severity at hospitalisation.

From bedside to recovery: exercise therapy for prevention of post-intensive care syndrome

BACKGROUND

As advancements in critical care medicine continue to improve Intensive Care Unit (ICU) survival rates, clinical and research attention is urgently shifting toward improving the quality of survival. Post-Intensive Care Syndrome (PICS) is a complex constellation of physical, cognitive, and mental dysfunctions that severely impact patients' lives after hospital discharge. This review provides a comprehensive and multi-dimensional summary of the current evidence and practice of exercise therapy (ET) during and after an ICU admission to prevent and manage the various domains of PICS. The review aims to elucidate the evidence of the mechanisms and effects of ET in ICU rehabilitation and highlight that suboptimal clinical and functional outcomes of ICU patients is a growing public health concern that needs to be urgently addressed.

MAIN BODY

This review commences with a brief overview of the current relationship between PICS and ET, describing the latest research on this topic. It subsequently summarises the use of ET in ICU, hospital wards, and post-hospital discharge, illuminating the problematic transition between these settings. The following chapters focus on the effects of ET on physical, cognitive, and mental function, detailing the multi-faceted biological and pathophysiological mechanisms of dysfunctions and the benefits of ET in all three domains. This is followed by a chapter focusing on co-interventions and how to maximise and enhance the effect of ET, outlining practical strategies for how to optimise the effectiveness of ET. The review next describes several emerging technologies that have been introduced/suggested to augment and support the provision of ET during and after ICU admission. Lastly, the review discusses future research directions.

CONCLUSION

PICS is a growing global healthcare concern. This review aims to guide clinicians, researchers, policymakers, and healthcare providers in utilising ET as a therapeutic and preventive measure for patients during and after an ICU admission to address this problem. An improved understanding of the effectiveness of ET and the clinical and research gaps that needs to be urgently addressed will greatly assist clinicians in their efforts to rehabilitate ICU survivors, improving patients' quality of survival and helping them return to their normal lives after hospital discharge.

Dyspnoea in COVID-19 recovery beyond the intensive care unit: the potential impact of inspiratory muscle weakness

Emerging evidence confirms that dyspnoea and inspiratory muscle weakness persist for up to 6 months following mechanical ventilation with #COVID19 pneumonia. Screening for inspiratory muscle weakness should be prioritised, as it may be treatable. https://bit.ly/3CBQXO2.