Evidence map›Paper›PMID 34585722›Full record

ArticleAnnals of work exposures and health2022

Physiological Impacts of Surgical Mask Coverage of Elastomeric Half-mask Respirator Exhalation Valves in Healthcare Workers.

Eileen Zhuang, Paul Thurman, Hegang H Chen, Melissa A McDiarmid, Stella E Hines

Open access · bronzeAbstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in Annals of work exposures and health, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 4 papers.

0numbers the graph read from it
0cells of the map it votes in
4citing papers in PubMed
0.7field-weighted citation impact, top 27% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

4 citing papers in PubMed, 5 citations in OpenAlex.

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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

5 authors at 1 institution in 1 country.

Eileen ZhuangDepartment of Medicine, Division of Pulmonary and Critical Care Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.ORCID 0000-0002-5149-8385
Paul ThurmanR Adams Cowley Shock Trauma Center, University of Maryland Medical Center, Baltimore, MD, USA.
Hegang H ChenDepartment of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore, MD, USA.
Melissa A McDiarmidDepartment of Medicine, Division of Occupational and Environmental Medicine, University of Maryland School of Medicine, Suite 200, Baltimore, MD, USA.
Stella E HinesDepartment of Medicine, Division of Pulmonary and Critical Care Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.
University of Maryland, Baltimore · US

Funding

CDC HHS 75D30120P09044Centers for Disease Control and Prevention-National Institute for Occupational Safety and Health 75D30120P09044NIOSH CDC HHS
6 · The paper itself

Abstract

objectivesElastomeric half-mask respirator (EHMR) use in healthcare increased significantly during the COVID-19 pandemic. Concern for potential release of infectious aerosols from EHMR exhalation valves prompted recommendations to cover them with surgical masks (SMs), thereby improving source control. The physiological and subjective effects of wearing a SM over the exhalation valve of an EHMR, however, are unknown.

methodsTwelve healthy healthcare worker volunteers completed a 30-min series of simulated healthcare-related tasks, including resting, talking, walking, and bending, proning and supinating a weighted manikin, and performing cardiopulmonary resuscitation. This series recurred three times with different mask configurations-SM only, EHMR only, or EHMR with SM covering the exhalation valve. A transcutaneous sensor continuously measured carbon dioxide (tcPCO2), oxygen saturation (SpO2), and heart rate (HR) from each subject. Subjects scored their rates of perceived exertion (RPE) and levels of discomfort after each round. Physiological parameters and subjective scores were analyzed using mixed linear models with a fixed effect for mask type, activity, age, body mass index (BMI), and gender. Analysis also tested for interaction between mask type and activity.

resultsPhysiological parameters remained within normal ranges for all mask configurations but varied by task. Statistically significant but small decreases in mean tcPCO2 (37.17 versus 37.88 mmHg, P < 0.001) and SpO2 (97.74 versus 97.94%, P < 0.001) were associated with wearing EHMR with SM over the exhalation valve compared with EHMR alone. Mean HR did not differ between these mask configurations. Wearing SM only was associated with lower RPE and level of discomfort compared with EHMR, but these subjective scores did not differ when comparing EHMR with SM to EHMR only. Age, BMI, and gender had no significant effect on any outcomes.

conclusionsWearing a SM over an EHMR did not produce clinically significant changes in tcPCO2, SpO2, or HR compared with uncovered EHMR during healthcare-related tasks. Covered EHMR use also did not affect perceived exertion or discomfort compared with uncovered EHMR use. Covering the exhalation valve of an EHMR with a SM for source control purposes can be done safely.

Indexed as

COVID-19Occupational ExposureExhalationHealth PersonnelHumansMasksPandemicsSARS-CoV-2Ventilators, Mechanicalcarbon dioxideCOVID-19elastomeric respiratorshealthcare workersheart rateoxygen saturationPPE

Identifiers

PMID34585722
PMCPMC8500049
OpenAlexW3201796226

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.