The impact of facemask on patients with COPD: A systematic review and meta-analysis

Safety implications of mask use: a systematic review and evidence map

BACKGROUND

Widespread use of respiratory protection masks has become a critical component of public health response.

OBJECTIVES

This systematic review synthesises the evidence on the acute physiological, cognitive and psychological impacts associated with different types of masks and provides an evidence map of research gaps.

METHODS

A comprehensive search from 2000 to 2023 was conducted across multiple databases (MEDLINE, EMBASE, Cochrane databases, Scopus and PubMed). An umbrella systematic overview was conducted for physiological outcomes using existing systematic reviews. We conducted de novo systematic reviews for cognitive and psychological outcomes. Pairs of independent reviewers determined eligibility, extracted data and assessed risk of bias. Certainty at an outcome level was appraised using the Grading of Recommendations Assessment, Development and Evaluation approach.

RESULTS

The search resulted in 13 370 potential citations, leading to the inclusion of nine systematic reviews for physiological outcomes (87 primary studies) and 10 primary studies for cognitive and psychological outcomes (3815 participants), with the majority of participants being healthy adults. Studies evaluating physiological outcomes demonstrated that various types of masks have little to no significant difference in heart rate (surgical mask (mean difference (MD): 0.96 (-1.01 to 2.93)), N95 mask (MD: 1.63 (-2.79 to 6.05)) and cloth mask (MD: -0.94 (-6.39 to 4.52))) or respiratory rate during rest or exercise (surgical mask (MD: -1.35 (-3.00 to 0.29)), N95 mask (MD: 0.10 (-3.10 to 3.29)) and cloth mask (MD: -2.57 (-6.44 to 1.29)) (low certainty for most outcomes)). Mask use may be associated with very small changes in minute ventilation (surgical mask (MD: -13.9 (-20.30 to -7.53)) and N95 mask (MD: -16.3 (-28.7 to -3.9))), tidal volume (surgical mask (MD: -0.14 (-0.23 to -0.05)) and N95 mask (MD: -0.10 (-0.33 to 0.13))), oxygen saturation (surgical mask (MD: -0.59% (-0.87 to -0.30)), N95 mask (MD: -0.35% (-0.75 to 0.05)) and cloth mask (MD: -0.50% (-1.23; 0.24))), carbon dioxide partial pressure (surgical mask (standardised MD (SMD): 1.17 (0.70 to 1.64)) and N95 mask (SMD: 0.43 (0.08 to 0.79))) and exercise performance (surgical mask (SMD: -0.12 (-0.39 to 0.15)), N95 mask (SMD: -0.42 (-0.76 to -0.08)) and cloth mask (SMD: -0.26 (-0.54 to 0.02)) (low certainty for most outcomes)). Studies evaluating cognitive outcomes showed mixed results. Some studies reported reduced mental workload, and others showed no significant effect or decreased performance. The impact on attention, errors and reaction time was variable. These studies were small and at moderate to high risk of bias. Evidence was insufficient to estimate the effect of mask use on psychological outcomes (claustrophobia, depression and anxiety) as these studies were small, non-longitudinal and at high risk of bias.

CONCLUSION

This evidence map provides a comprehensive insight into the multifaceted impact of respiratory protection mask use, and highlights the limited certainty in the available body of evidence. This evidence map supports the development of future research agenda.

Assessing the impact of diverse mask types on COPD patients: a randomised controlled trial study protocol

INTRODUCTION

Wearing masks has proven beneficial in preventing respiratory pathogen infections in individuals with chronic obstructive pulmonary disease (COPD). However, the impact of different mask types on physiological indicators and daily physical activity in COPD patients remains uncertain. This study aims to assess the immediate effects of various mask types on cardiopulmonary function indicators, subjective perceptions and the 6-minute walking distance (6MWD) in individuals with COPD.

METHODS AND ANALYSIS

This randomised controlled trial will enrol 129 stable COPD patients. Participants will be randomly divided into three groups: control, N95 mask and surgical mask groups. Each group will undergo both a 6-minute seated test and a 6-minute walk test (6MWT), without or with their respective masks. A 10-minute interval will be provided between the two phases. The primary indicators of the study include the 6MWD and blood oxygen saturation. Secondary outcomes encompass blood pressure, pulse rate, Borg score, Rate of Perceived Exertion (RPE) score and subjective perception score. Oxygen saturation, pulse rate and blood pressure will be recorded four times during the trial, while Borg and RPE scores will be compared before and after the 6MWT. Additionally, subjective perception scores will be collected after each mask-wearing stage.

ETHICS AND DISSEMINATION

This study has received approval from the Ethics Committee of the Affiliated Hospital of Gansu University of Chinese Medicine (approval number: 202335). We plan to disseminate research results through publication in a peer-reviewed journal or presentation at a conference.

TRIAL REGISTRATION NUMBER

ChiCTR2300074554.

Air pollution and COPD: GOLD 2023 committee report

Exposure to air pollution is a major contributor to the pathogenesis of COPD worldwide. Indeed, most recent estimates suggest that 50% of the total attributable risk of COPD may be related to air pollution. In response, the Global Initiative for Chronic Obstructive Lung Disease (GOLD) Scientific Committee performed a comprehensive review on this topic, qualitatively synthesised the evidence to date and proffered recommendations to mitigate the risk. The review found that both gaseous and particulate components of air pollution are likely contributors to COPD. There are no absolutely safe levels of ambient air pollution and the relationship between air pollution levels and respiratory events is supra-linear. Wildfires and extreme weather events such as heat waves, which are becoming more common owing to climate change, are major threats to COPD patients and acutely increase their risk of morbidity and mortality. Exposure to air pollution also impairs lung growth in children and as such may lead to developmental COPD. GOLD recommends strong public health policies around the world to reduce ambient air pollution and for implementation of public warning systems and advisories, including where possible the use of personalised apps, to alert patients when ambient air pollution levels exceed acceptable minimal thresholds. When household particulate content exceeds acceptable thresholds, patients should consider using air cleaners and filters where feasible. Air pollution is a major health threat to patients living with COPD and actions are urgently required to reduce the morbidity and mortality related to poor air quality around the world.