Translate this page into:
Long-term effects of use of personal protective equipment on cognitive functions of healthcare workers: A case-control study
*Corresponding author: Parikshit Ashok Muley, Department of Physiology, Datta Meghe Medical College and Shalinitai Meghe Hospital and Research Center, Wanadongri, Maharashtra, India. drparikshit19@yahoo.com
-
Received: ,
Accepted: ,
How to cite this article: Singh P, Waghmare SN, Muley P, Muley PA. Long-term effects of use of personal protective equipment on cognitive functions of healthcare workers: A case-control study. J Neurosci Rural Pract. doi: 10.25259/JNRP_450_2024
Abstract
Objectives:
The COVID-19 pandemic affected 216 countries, leading to high death rates worldwide. Front-line healthcare workers (HCWs) were at greater risk of contracting COVID-19 than the general population. Healthcare systems and HCWs must provide proper case management while ensuring their safety. For HCWs, this involves using personal protective equipment (PPE) while treating suspected cases. During their duties in COVID-19 wards, HCWs must wear PPE for extended periods, sometimes more than 6–8 h, leading to problems such as headaches, dizziness, anxiety, lack of attention, visual and hearing problems, dyspnea, hypoxia, and suffocation. The objective of this study was to assess the cognitive functions of HCWs working in PPE for long durations. The secondary objective was to investigate the association between long-term PPE use and cognitive functions in HCWs.
Materials and Methods:
A total of 128 HCWs were divided into four groups based on the duration of PPE use: Group 1 (short duration group: Less than 6 h/day), Group 2 (moderate duration group: More than 6 h but <8 h/day), Group 3 (long duration group: More than 8 h/day), and a control group with no PPE use. After obtaining valid consent, the selected participants underwent cognitive assessments following their COVID-19 duty. The cognitive parameters assessed included attention (auditory and visual reaction times) and executive functions (Stroop test and Eriksen flanker test [EFT]).
Results:
The results showed a positive correlation between the duration of PPE use and cognitive function scores in the attention and executive function domains, specifically in visual and auditory reaction times, Stroop test performance, and EFT results.
Conclusion:
The study concluded that HCWs with more than 8 h of continuous PPE duty were more vulnerable to adverse neurocognitive effects compared to HCWs with 6–8 h or <6 h of PPE use. These findings can serve as a basis for developing better protocols for PPE usage among HCWs and implementing precautionary measures before PPE duty. Regular screening of HCWs for potential cognitive decline should also be promoted.
Keywords
Cognitive functions
Healthcare workers
Personal protective equipment
INTRODUCTION
The COVID-19 pandemic caused many countries to suffer, leading to high death rates worldwide. Front-line healthcare workers (HCWs) were at greater risk of contracting COVID-19 than the general population. Healthcare systems and HCWs were focused on managing cases while ensuring safety. For HCWs, this involved the use of personal protective equipment (PPE) while treating suspected cases, following international guidelines.[1,2]
During their duty in COVID-19 wards, HCWs had to wear PPE continuously for more than 6–8 h, which led to many problems such as headaches, dizziness, anxiety, lack of attention, visual and hearing problems, dyspnea, hypoxia, and suffocation.[3-5] Various research studies have observed that prolonged use of PPE can cause intermittent hypoxia, which may also induce cognitive decline due to neuroinflammation in microglia. Studies have shown that microglia-mediated inflammation plays a role in intermittent hypoxia-induced cognitive decline.[6,7]
Many studies addressing this topic were limited to questionnaire assessments and analysis of the acute effects of PPE use in HCWs.[8] The uniqueness of this study lies in its focus on diagnosing long-term chronic complications faced by HCWs working in PPE in COVID-19 wards.
Thus, the objective of this study is to assess the cognitive functions of HCWs working in PPE for long durations and to explore the association between long-term PPE use and cognitive functions in HCWs. This study aims to evaluate the long-term effects of PPE on cognitive function parameters in HCWs working in COVID-19 wards, providing a proper diagnostic assessment of the chronic complications they face.
MATERIALS AND METHODS
This is an analytical case–control study. The 128 volunteers in the study were categorized into four groups: Group 1 (short duration group – <6 h/day), Group 2 (moderate duration group – more than 6 h but <8 h/day), Group 3 (long duration group – more than 8 h/day), and the control group (no history of PPE use), as shown in Table 1.
| Group | Study group (PPE duration) | n(sample) | Duration of exposure to PPE |
|---|---|---|---|
| Group 1 | <6 h | 32 | Short duration exposure group |
| Group 2 | 6–8 h | 32 | Moderate duration exposure group |
| Group 3 | >8 h | 32 | Long duration exposure group |
| Control | Control (no history of PPE use) | 32 | Control group - No history of exposure |
PPE: Personal protective equipment.
Each group contained an equal distribution of 32 subjects. After obtaining valid written consent, the following inclusion and exclusion criteria were applied:
Inclusion criteria
HCWs who provided written consent and had a complete vaccination certificate. HCWs who worked in PPE for 6 or more hours in the COVID-19 ward of the hospital. HCWs who had completed a minimum of 1 month of duty in the COVID-19 ward.
Exclusion criteria
Volunteers with any history of systemic disorders, such as diabetes and hypertension. Volunteers who had taken medications in the past month. Volunteers with a history of chronic addiction or <1 month of COVID-19 ward duty.
Cognitive functions of each group were measured using cognitive function software available online, which has high accuracy and was conveniently performed on a computer.
Attention domain
The attention domain was assessed using two tests: Visual and auditory reaction time (VRT and ART).
VRT
VRT is an indicator of attention, measuring the time taken to react to a sudden change in visual stimuli. This test measures the VRT score in milliseconds (ms) with high accuracy and can be conveniently performed on a computer. The average VRT for a healthy individual is expected to be around 250 ms (0.25 s).
ART
ART is also an indicator of attention, measuring the time taken to react to a sudden change in auditory stimuli. This test measures the ART score in ms with high accuracy and can be performed conveniently on a computer. The average ART for a healthy individual is expected to be around 200 ms (0.2 s).
Executive function domain
The executive function domain was assessed using two tests: The color reading interference test (Stroop test) and the Eriksen flanker test (EFT).
Color reading interference (Stroop test)
In this variant of the classic Stroop test, there is a dissonance between the color presented and the mismatched name, which interferes with naming the color. The Stroop test causes elevated activation in the anterior cingulate cortex, which is involved in detecting the incongruity.
EFT
This test involves an interference task where different inputs compete with the target, slowing down the response speed. The variant used in this study involved identifying the direction of the central arrow among surrounding arrows.
Data analysis was performed using the Statistical Package for the Social Sciences version 23.0 software.
RESULTS
As shown in Table 2 and Figure 1, the statistical analysis of the VRT indicates that Group 3, with >8 h of PPE duration, had the maximum VRT of 334.23 ms, whereas Group 1, with <6 h of PPE duration, had the minimum VRT of 296.91 ms, compared to the VRT of the control group, which was 264.52 ms. Group 2, with 6–8 h of PPE duration, had an intermediate VRT of 315.16 ms. These data show a positive correlation between the duration of PPE use and VRT, i.e., the longer the PPE use, the higher the VRT.
| Group | Study group (PPE duration) | n(sample) | Mean±standard deviation | Standard error mean | P-value |
|---|---|---|---|---|---|
| Group 1 | <6 h | 32 | 296.91±8.95 | 1.58 | <0.0001 |
| Group 2 | 6–8 h | 32 | 315.16±5.76 | 1.01 | <0.0001 |
| Group 3 | >8 h | 32 | 334.23±8.91 | 1.57 | <0.0001 |
| Control group | Control (no history of PPE use) | 32 | 264.52±16.44 | 2.91 |
PPE: Personal protective equipment.
- Visual reaction time (VRT) in all groups. PPE: Personal protective equipment.
As shown in Table 3 and Figure 2, the statistical analysis of the ART reveals that Group 3, with >8 h of PPE duration, had the maximum ART of 295.28 ms, while Group 1, with <6 h of PPE duration, had the minimum ART of 258.08 ms, compared to the ART of the control group, which was 231.21 ms. Group 2, with 6–8 h of PPE duration, had an intermediate ART of 276.65 ms. These data show a positive correlation between the duration of PPE use and ART, i.e., the longer the PPE use, the higher the ART.
| Study group (PPE duration) | n(sample) | Mean±standard deviation | Standard error mean | P-value |
|---|---|---|---|---|
| <6 h | 32 | 258.08±9.11 | 1.61 | <0.0001 |
| 6-8 h | 32 | 276.65±6.75 | 1.21 | <0.0001 |
| >8 h | 32 | 295.28±8.41 | 1.48 | <0.0001 |
| Control | 32 | 231.21±15.31 | 2.71 |
PPE: Personal protective equipment.
- Auditory reaction time in all groups. PPE: Personal protective equipment.
As shown in Table 4 and Figure 3, the statistical analysis of the color Stroop test shows that Group 3, with >8 h of PPE duration, had the maximum Stroop time of 1475.09 ms, while Group 1, with <6 h of PPE duration, had the minimum Stroop time of 1114.06 ms, compared to the Stroop time of the control group, which was 924.96 ms. Group 2, with 6–8 h of PPE duration, had an intermediate Stroop time of 1291.43 ms. These data show a positive correlation between the duration of PPE use and color Stroop time, i.e., the longer the PPE use, the higher the color Stroop time.
| Study group (PPE duration) | n(sample) | Mean±standard deviation | Standard error mean | P-value |
|---|---|---|---|---|
| <6h | 32 | 1114.06±59.32 | 10.48 | <0.0001 |
| 6–8 h | 32 | 1291.43±62.08 | 10.97 | <0.0001 |
| >8 h | 32 | 1475.09±72.72 | 12.85 | <0.0001 |
| Control | 32 | 924.96±67.45 | 11.92 |
PPE: Personal protective equipment.
- Color Stroop test in all groups. PPE: Personal protective equipment.
As shown in Table 5 and Figure 4, the statistical analysis of the EFT reveals that Group 3, with >8 h of PPE duration, had the maximum EFT time of 1575.21 ms, whereas Group 1, with <6 h of PPE duration, had the minimum EFT time of 1220.53 ms, compared to the EFT time of the control group, which was 1024.71 ms. Group 2, with 6–8 h of PPE duration, had an intermediate EFT time of 1401.31 ms. These data show a positive correlation between the duration of PPE use and the EFT results, i.e., the longer the PPE use, the higher the EFT time.
| Study group (PPE duration) | n(sample) | Mean±standard deviation | Standard error mean | P-value |
|---|---|---|---|---|
| <6 h | 32 | 1220.53±58.54 | 10.34 | <0.0001 |
| 6–8 h | 32 | 1401.31±64.39 | 11.38 | <0.0001 |
| >8 h | 32 | 1575.21±67.86 | 11.99 | <0.0001 |
| Control | 32 | 1024.71±71.44 | 12.63 |
PPE: Personal protective equipment.
- Eriksen flanker test in all groups. PPE: Personal protective equipment.
DISCUSSION
The main purpose of our study was to examine the chronic effects of prolonged PPE use on the cognitive functions of HCWs and provide a proper diagnostic assessment of the chronic complications they face. Previous studies on this topic have primarily focused on questionnaire-based assessments and the analysis of acute effects of PPE use in HCWs.[8] In contrast, our study specifically investigates the long-term, chronic complications faced by HCWs working in COVID-19 wards while wearing PPE.
The results of our research indicate that cognitive function readings are clinically significant and show a correlation with the duration of PPE use in HCWs. The cognitive functions assessed in the study – VRT, ART, color Stroop, and EFT – are based on basic reaction times and are measured in ms. These functions exhibit a positive correlation with the duration of PPE use in HCWs. Specifically, Group 3, which had the longest PPE use duration (>8 h), exhibited the highest reaction times, while Group 1, which had the shortest PPE use duration (<6 h), had the lowest reaction times. Group 2, with an intermediate duration (6–8 h), showed reaction times between those of the other two groups. The observation suggests that as the PPE duration increases the reaction time also increases (means there is slower reaction time), and it is indicative of decline in cognitive function.
PPE for HCWs is typically made from spunbond-meltblownspunbond laminate polypropylene fiber, which acts as an obstacle to heat loss and ventilation. As a result, prolonged use of PPE can cause heat strain, which in turn affects cognitive functions. Our findings are consistent with those of Foster et al.,[9] who conducted a study in 2020 on occupational heat stress and practical cooling solutions for HCWs and industry workers during the COVID-19 pandemic. This study showed that prolonged use of PPE can induce hypoxia in HCWs. Moreover, as observed in the study by Liu et al., intermittent hypoxia can lead to cognitive decline due to neuroinflammation in microglia.[7]
CONCLUSION
As observed from the results of this research, cognitive function test scores are significantly correlated with the duration of PPE use. This suggests that HCWs who have been using PPE for more than 8 h continuously are more vulnerable to adverse effects, including neurocognitive decline. The findings from this study can serve as a foundation for developing better protocols for the proper use of PPE by HCWs. In addition, precautionary prophylactic measures should be implemented before HCWs begin their PPE duties, and regular screening should be promoted to monitor and address any cognitive decline or related complications.
Ethical approval:
Institutional review board approval is not required, as the protocol and study was approved by Indian Council of Medical Research (ICMR).
Declaration of patient consent:
The authors certify that they have obtained all appropriate patient consent.
Conflicts of interest:
There are no conflicts of interest.
Use of artificial intelligence (AI)-assisted technology for manuscript preparation:
The authors confirm that there was no use of artificial intelligence (AI)-assisted technology for assisting in the writing or editing of the manuscript and no images were manipulated using AI.
Financial support and sponsorship: Nil.
References
- Coronavirus disease (COVID-19) pandemic. Available from: https://www.who.int/emergencies/diseases/novel-coronavirus-2019 [Last accessed on 2024 Dec 10]
- [Google Scholar]
- The COVID-19 pandemic, personal protective equipment and respirator: A narrative review. Int J Clin Pract. 2020;74:e13578.
- [CrossRef] [Google Scholar]
- Personal protective equipment and COVID-19. N Engl J Med. 2020;382:e105.
- [CrossRef] [Google Scholar]
- Estimating the burden of COVID-19 on Australian healthcare workers and the health system during the first six months of the pandemic. Int J Nurs Stud. 2021;114:103811.
- [CrossRef] [PubMed] [Google Scholar]
- COVID-19-associated hospitalizations among health care personnel-COVID-NET, 13 States, march 1-May 31, 2020. MMWR Morb Mortal Wkly Rep. 2020;69:1576-83.
- [CrossRef] [PubMed] [Google Scholar]
- Neuroinflammation in the pathogenesis of Alzheimer's disease. A rational framework for the search of novel therapeutic approaches. Front Cell Neurosci. 2014;8:112.
- [CrossRef] [PubMed] [Google Scholar]
- The relationship between inflammation and neurocognitive dysfunction in obstructive sleep apnea syndrome. J Neuroinflammation. 2020;17:229.
- [CrossRef] [PubMed] [Google Scholar]
- COVID-19 and healthcare workers: A systematic review and meta-analysis. Int J Infect Dis. 2021;104:335-46.
- [CrossRef] [PubMed] [Google Scholar]
- Occupational heat stress and practical cooling solutions for healthcare and industry workers during the COVID-19 pandemic. Ann Work Expo Health. 2020;64:915-22.
- [CrossRef] [PubMed] [Google Scholar]