Sonographic Diaphragm Abnormalities are an Unexpectedly Frequent Feature of Long COVID Outpatients with Unexplained Dyspnea and Fatigue (preprint)

Purpose The primary aim of this study is to define the sonographic diaphragm phenotype of Long COVID rehabilitation outpatients with non-specific dyspnea and fatigue. We analyzed patients referred from a pulmonary post-COVID clinic that were lacking a specific cardiopulmonary diagnosis for their symptoms. Additionally, we report the functional outcomes of subset of patients who completed an outpatient cardiopulmonary physical therapy program.Methods This was a retrospective cohort study (n = 58) of consecutive patients referred for neuromuscular ultrasound assessment of diaphragm muscle using B-mode technique. Patients were recruited from a single academic hospital between February 25, 2021 and November 22, 2022.Results Sonographic abnormalities were identified in 57% (33/58) of patients, and in the vast majority of cases (33/33) was defined by a low diaphragm muscle thickness. Thinner diaphragm muscles are correlated with lower serum creatinine and creatine kinase values, but there was no association with markers of systemic inflammation. Thirty three patients participated in outpatient cardiopulmonary physical therapy that included respiratory muscle training, and 75.8% (25/33) had documented improvement.Conclusion In the outpatient rehabilitation setting, patients with Long COVID display low diaphragm muscle thickness, but intact muscle contractility, with surprising frequency on neuromuscular ultrasound. We speculate this represents a form of disuse atrophy. Also, these patients appear to have a favorable response to cardiopulmonary physical therapy that includes respiratory muscle training.

Sonographic Diaphragm Dysfunction is an Unexpectedly Frequent Feature of Long COVID with Non-Specific Dyspnea and Fatigue (preprint)

Introduction/Aims The primary aim of this study is to define the sonographic diaphragm phenotype of Long COVID patients with non-specific dyspnea and fatigue. We analyzed patients referred from a pulmonary medicine COVID clinic without any intrinsic cardiopulmonary explanation for their new symptoms. Additionally, we report the functional outcomes of patients who completed an outpatient cardiopulmonary physical therapy program. Methods This was a retrospective cohort study (n = 37) of consecutive patients referred for neuromuscular assessment centered on B-mode ultrasound of the diaphragm muscle. Patients were recruited from a single academic hospital between February 25, 2021 and October 7, 2021. Results Sonographic abnormalities were identified in 65% (24/37) of patients, and in the vast majority of cases (23/24) was defined by low diaphragm muscle thickness. Thinner diaphragm muscles positively correlated with lower serum creatinine and creatine kinase values, but there was no association with markers of systemic inflammation. Eighteen patients participated in outpatient cardiopulmonary physical therapy that included respiratory muscle training, and 77.8% (n=14) had documented improvement. Discussion In the outpatient rehabilitation setting, patients with Long COVID frequently display low diaphragm muscle thickness, but intact muscle contractility on sonographic studies. We speculate this represents a form of disuse atrophy, which has a good response rate to cardiopulmonary physical therapy.

Speech intelligibility in respiratory protective equipment - Implications for verbal communication in critical care

Respiratory protective equipment (RPE) such as filtering facepiece respirators, elastomeric respirators and powered air-purifying respirators are routinely worn in the critical care unit as a component of personal protective equipment (PPE) when caring for patients with coronavirus disease 2019 (COVID-19). It is the authors’ anecdotal experience that RPE may, however, inadvertently interfere with verbal communication between critical care staff. The literature pertaining to the effects of RPE wear on verbal communication was therefore reviewed. A literature search returned 98 articles, and 4 records were identified from other sources;after screening for content relevancy, 15 experimental studies were included in the narrative synthesis. Previous studies in both healthcare and other occupational settings suggest a detrimental impact on speech intelligibility, varying according to RPE type and test conditions. The effects of background noise and potential for increased cognitive load through compensatory behaviours are also identified. The clinical significance of these effects remains uncertain though, as evidence measuring clinical outcomes or errors is lacking. Mitigating strategies include increasing speech intelligibility through environmental changes and technology;modifying verbal communication strategies;and decreasing reliance on verbal communication where possible.