Impact of personal protective equipment on clinical output and perceived exertion

Literature review of physiological strain of personal protective equipment on personnel in the high-consequence infectious disease isolation environment

BACKGROUND

Heat strain and dehydration can affect an individual's physical and mental performance. The purpose of this review was to examine the literature for the impact of heat strain on health care workers (HCWs) who care for patients with high-consequence infectious diseases (HCIDs) while wearing personal protective equipment (PPE), discuss the risks of impaired safety caused by heat strain and dehydration in HCID environments, identify attempts to combat PPE-related heat strain, recognize limitations, and provide suggestions for further research.

METHODS

A literature search was performed in PubMed or MEDLINE and Google Scholar. Authors screened abstracts for inclusion criteria and reviewed articles if the abstracts were considered to include information relevant to the aim.

RESULTS

The search terms yielded 30 articles that were sorted based on environment setting, physiological impact, and interventions.

DISCUSSION

The safety of the HCWs and patients can be enhanced through the development and usage of cooler, more comfortable PPE materials and ensembles to help slow the rate of dehydration and support the regulation of core body temperature.

CONCLUSIONS

Heat strain caused by wearing PPE is an occupational health concern for HCWs in the high-risk environment, that is, HCID care. Future studies are needed to develop innovative PPE ensembles that can reduce heat strain and improve well-being.

Effect of Physical Activity and Exercise on the Level of COVID-19 Antibodies and Lifestyle-Related Factors among Vaccinated Health Science Center (HSC) Students: A Pilot Randomized Trial

A vaccine is a type of medicine that increases immunity and the number of antibodies (IgM and IgG) when injected into the body, preparing it in case of an actual viral infection. It has been shown in several studies that there is a significant relationship between physical activity and vaccination. Furthermore, it has been documented that physical activity can play a major role in reducing stress. Evidence also shows the existence of a relationship between immunity, vaccine response, and sleep duration. To investigate the effects of physical activity on the level of COVID-19 antibodies and lifestyle-related factors, Health Science Center (HSC) students who had taken the third dose of the vaccine and had no prior infection of the COVID-19 virus were investigated. To serve the purpose of this study, an anti-SARS-CoV-2 test was applied by taking a blood sample from the students. The Perceived Stress Scale (PSS) and Pittsburgh Sleep Quality Index (PSQI) questionnaires and the Borg’s 15-point scale were given to the participants to fill out. The study utilized a two-arm randomized control research design in which 40 participants were randomly assigned into one of two groups, either the control group (n = 20) or the treatment group (n = 20). All tests and assessments were performed before and after intervention for both groups. The control group walked less than 5000 steps every day for one month with a 20 min rest during the exercise session, while the treatment group walked more than 12,000 steps every day for the same time and exercise task session. The students’ steps were monitored using an Apple watch. There was a significant decrease in the IgG antibody level in the treatment group compared to the control group (p < 0.001). The IgM antibody level of all groups did not show any significant difference before starting the intervention. However, there was a significant (p < 0.05) decrease in the IgM level of the treatment group after treatment compared to before treatment. Moreover, there was a significant decrease in the treatment group’s stress level and sleep disruption, indicating better sleep quality, compared to the control group (p < 0.035). The levels of IgG and IgM did not improve for the treatment group. However, the treatment group improved their stress level and sleep disruption. Therefore, further rigorous research is needed to investigate vaccine efficacy among more physically active people.

The Evaluation of Physiological Index Changes and Safety Work of Female Medical Staff With Different Medical Protection Standards in the Ward of COVID-19

Background

Effective personal protective equipment (PPE) contribute to the prevention of COVID-19 infection. However, it is necessary to evaluate the potential risk of different medical protections in the isolation ward of COVID-19.

Objectives

We aimed to explore the dynamics in physiological indexes of medical staff under primary and secondary PPE in the isolation ward of COVID-19 and provide the scientific basis for determining the safe work strategy.

Materials and Methods

In this study, 30 female nurses were selected to simulate medical work under the primary or secondary PPE, respectively. The oral temperature, axillary temperature, heart rate, respiratory rate, blood oxygen saturation, and blood pressure were measured and recorded every 20 min. The subjective adverse symptoms were recorded every 30 min. The blood glucose and weight of the individuals were measured and recorded before and after the trial.

Results

The results indicated that the median trial persistence time in the participants with moderate-intensity work wearing the secondary PPE (70.0 min) was much lower than that with moderate-intensity work wearing the primary PPE (180 min) and with light-intensity work wearing the primary PPE (110 min; p < 0.05). Importantly, the heart rate, oral/axillary temperature, and respiratory rate of physiological indexes of the participants under moderate-intensity work wearing the secondary PPE increased significantly faster than the primary PPE (p < 0.001), while blood oxygen saturation decreased significantly faster than the primary PPE (p < 0.001). In addition, the proportions of subjective adverse symptoms (such as dry mouth, dizziness, palpitations, and anhelation) were much higher than primary PPE (p < 0.001). The average sweat volume and blood glucose consumption of participants under moderate-intensity work wearing primary PPE were higher than secondary PPE (p < 0.001).

Conclusion

The combination of an exacerbated workload and secondary PPE worn by COVID-19 healthcare workers increases the change in physiological indicators, and in some cases the adverse symptoms, which can affect and even suspend their medical work. For any medical institution, there is room for improvement in terms of bioethics of a "Job Well Done" to reduce the risks of medical activities under secondary PPE.

Establishing Healthcare Worker Performance and Safety in Providing Critical Care for Patients in a Simulated Ebola Treatment Unit: Non-Randomized Pilot Study

Improving the provision of supportive care for patients with Ebola is an important quality improvement initiative. We designed a simulated Ebola Treatment Unit (ETU) to assess performance and safety of healthcare workers (HCWs) performing tasks wearing personal protective equipment (PPE) in hot (35 °C, 60% relative humidity) or thermo-neutral (20 °C, 20% relative humidity) conditions. In this pilot phase to determine the feasibility of study procedures, HCWs in PPE were non-randomly allocated to hot or thermo-neutral conditions to perform peripheral intravenous (PIV) and midline catheter (MLC) insertion and endotracheal intubation (ETI) on mannequins. Eighteen HCWs (13 physicians, 4 nurses, 1 nurse practitioner; 2 with prior ETU experience; 10 in hot conditions) spent 69 (10) (mean (SD)) minutes in the simulated ETU. Mean (SD) task completion times were 16 (6) min for PIV insertion; 33 (5) min for MLC insertion; and 16 (8) min for ETI. Satisfactory task completion was numerically higher for physicians vs. nurses. Participants’ blood pressure was similar, but heart rate was higher (p = 0.0005) post-simulation vs. baseline. Participants had a median (range) of 2.0 (0.0–10.0) minor PPE breaches, 2.0 (0.0–6.0) near-miss incidents, and 2.0 (0.0–6.0) health symptoms and concerns. There were eight health-assessment triggers in five participants, of whom four were in hot conditions. We terminated the simulation of two participants in hot conditions due to thermal discomfort. In summary, study tasks were suitable for physician participants, but they require redesign to match nurses’ expertise for the subsequent randomized phase of the study. One-quarter of participants had a health-assessment trigger. This research model may be useful in future training and research regarding clinical care for patients with highly infectious pathogens in austere settings.

Impact of Personal Cooling on Performance, Comfort and Heat Strain of Healthcare Workers in PPE, a Study From West Africa

Background: Personal protective equipment (PPE) is an essential component of safely treating suspected or confirmed SARS-CoV-2 patients. PPE acts as a barrier to heat loss, therefore increasing the risk of thermal strain which may impact on cognitive function. Healthcare workers (HCWs) need to be able to prioritize and execute complex tasks effectively to ensure patient safety. This study evaluated pre-cooling and per-cooling methods on thermal strain, thermal comfort and cognitive function during simulated emergency management of an acutely unwell patient. Methods: This randomized controlled crossover trial was run at the Clinical Services Department of the Medical Research Unit The Gambia. Each participant attended two sessions (Cool and Control) in standard PPE. Cool involved pre-cooling with an ice slurry ingestion and per-cooling by wearing an ice-vest external to PPE. Results: Twelve participants completed both sessions. There was a significant increase in tympanic temperature in Control sessions at both 1 and 2 h in PPE (p = 0.01). No significant increase was seen during Cool. Effect estimate of Cool was -0.2°C (95% CI -0.43; 0.01, p = 0.06) post 1 h and -0.28°C (95% CI -0.57; 0.02, p = 0.06) post 2 h on tympanic temperature. Cool improved thermal comfort (p < 0.001), thermal sensation (p < 0.001), and thirst (p = 0.04). No difference on cognitive function was demonstrated using multilevel modeling. Discussion: Thermal strain in HCWs wearing PPE can be safely reduced using pre- and per-cooling methods external to PPE.

Managing surgical patients with a COVID-19 infection in the operating room: An experience from Indonesia

Background

The Coronavirus and the COVID-19 pandemic in 2020 have significantly impacted hospital care, including surgery practice. Hospitals must balance patient care, staff safety, resource availability, and medical ethics. Differences in community infection trends, national policies, availability of resources and technology, plus local circumstances may make uniform management impossible globally. This paper described the practical workflow of emergency COVID-19 surgery in a tertiary referral national hospital in Indonesia.

Method

This study focused on the process of preparation for COVID-19 surgery from March 2020-March 2021. We also described the available facilities in terms of equipment and human resources.

Results

Steps of COVID-19 surgery preparations were described, such as the setup of general and infectious triage in the emergency department, development of preoperative screening protocol for COVID-19, designation of a specialized COVID-19 operating room and surgical staff, changes in preoperative surgery and anesthesia workflow, development of checklists and postoperative monitoring on staff health.

Conclusions

Changes in the workflow are essential during the pandemic for safe surgery. These changes require a multidisciplinary approach, communication, and a continued willingness to adapt. We recommend local adaptation of our general workflow for emergency surgery during an epidemic or pandemic.

Personal Protective Equipment in COVID-19: Impacts on Health Performance, Work-Related Injuries, and Measures for Prevention

OBJECTIVE

To assess impact of personal protective equipment (PPE) on healthcare providers (HCPs) in caring for COVID-19 patients.

METHODS

A cross-sectional survey was conducted over 50 hospitals in China. Descriptive analyses and Chi-square tests were performed on the collected data.

RESULTS

All 104 frontline HCPs report negative impacts of PPE on their clinical performance, 97% of them experienced discomfort and injuries caused by wearing PPE for long hours. Frontline HCPs provided suggestions to alleviate the negative impacts and to enhance communication between healthcare staff and patients. Two hundred eighty two non-frontline HCPs also revealed similar problems; however, we recorded a few discrepancies between answers given by frontline and non-frontline HCPs.

CONCLUSIONS

Wearing PPE for long hours degrades health performance. Measures were suggested to improve the design of PPE for protecting HCPs and enhancing their services to COVID patients.

Predicting Health Care Workers' Tolerance of Personal Protective Equipment: An Observational Simulation Study

BACKGROUND

More recently, due to the coronavirus disease 2019 pandemic, health care workers have to deal with clinical situations wearing personal protective equipment (PPE); however, there is a question of whether everybody will tolerate PPE equally. The main objective of this study was to develop a risk model to predict whether health care workers will tolerate wearing PPE, C category, 4B/5B/6B type, during a 30-minute simulation.

METHODS

A nonexperimental simulation study was conducted at the Advanced Simulation Center, Faculty of Medicine, Valladolid University (Spain) from April 3rd to 28th, 2017. Health care students and professionals were equipped with PPE and performed a 30-minute simulation. Anthropometric, physiological, and analytical variables and anxiety levels were measured before and after simulation. A scoring model was constructed.

RESULTS

Ninety-six volunteers participated in the study. Half the sample presented metabolic fatigue in the 20 minutes after finishing the simulation. The predictive model included female sex, height, muscle and bone mass, and moderate level of physical activity. The validity of the main model using all the variables presented an area under the curve of 0.86 (95% confidence interval: 0.786-0.935), and the validity of the model had an area under the curve of 0.725 (95% confidence interval: 0.559-0.89).

CONCLUSIONS

Decision-making in biohazard incidents is a challenge for emergency team leaders. Knowledge of health care workers' physiological tolerance of PPE could improve their performance.

Heat Adaptation in Military Personnel: Mitigating Risk, Maximizing Performance

The study of heat adaptation in military personnel offers generalizable insights into a variety of sporting, recreational and occupational populations. Conversely, certain characteristics of military employment have few parallels in civilian life, such as the imperative to achieve mission objectives during deployed operations, the opportunity to undergo training and selection for elite units or the requirement to fulfill essential duties under prolonged thermal stress. In such settings, achieving peak individual performance can be critical to organizational success. Short-notice deployment to a hot operational or training environment, exposure to high intensity exercise and undertaking ceremonial duties during extreme weather may challenge the ability to protect personnel from excessive thermal strain, especially where heat adaptation is incomplete. Graded and progressive acclimatization can reduce morbidity substantially and impact on mortality rates, yet individual variation in adaptation has the potential to undermine empirical approaches. Incapacity under heat stress can present the military with medical, occupational and logistic challenges requiring dynamic risk stratification during initial and subsequent heat stress. Using data from large studies of military personnel observing traditional and more contemporary acclimatization practices, this review article (1) characterizes the physical challenges that military training and deployed operations present (2) considers how heat adaptation has been used to augment military performance under thermal stress and (3) identifies potential solutions to optimize the risk-performance paradigm, including those with broader relevance to other populations exposed to heat stress.

Graphene Modified Multifunctional Personal Protective Clothing

Personal protective clothing is intended to protect the wearer from various hazards (mechanical, biological, chemical, thermal, radiological, etc.) and inhospitable environmental conditions that may cause harm or even death. There are various types of personal protective clothing, manufactured with different materials based on hazards and end user requirements. Conventional protective clothing has impediments such as high weight, bulky nature, lack of mobility, heat stress, low heat dissipation, high physical stress, diminishing dexterity, diminishing scope of vision, lack of breathability, and reduced protection against pathogens and hazards. By virtue of the superlative properties of graphene, fabrics modified with this material can be an effective means to overcome these limitations and to improve properties such as mechanical strength, antibacterial activity, flame resistance, conductivity, and UV resistance. The limitations of conventional personal protective equipment are discussed, followed by necessary measures which might be taken to improve personal protective equipment (PPE), the unique properties of graphene, methods of graphene incorporation in fabrics, and the current research status and potential of graphene-modified performance textiles relevant to PPE.

Environmental temperature and case fatality of patients with Ebola virus disease in Sierra Leone and Liberia, 2014-2015: a retrospective cohort study

OBJECTIVE

Fluid loss during Ebola virus disease (EVD) infections from gastrointestinal dysfunction leads to volume depletion. It is possible that high environmental temperatures may exacerbate volume depletion or interfere with the provision of medical care by providers in full personal protective equipment. We investigated the effect of environmental temperature on case fatality.

METHODS

The International Medical Corps (IMC) operated five Ebola Treatment Units (ETUs) in Liberia and Sierra Leone during the 2014-2016 epidemic. Demographic and outcomes variables for 465 patients with EVD were sourced from a de-identified, quality-checked clinical database collected by IMC. Daily environmental temperature data for Liberia and Sierra Leone were collected from a publicly available database (Weather Underground). Mean daily environmental temperatures were averaged across each patient's ETU stay and environmental temperature thresholds were determined. Multiple logistic regression was utilised, with forward variable selection and threshold for entry of P < 0.1. Statistical significance was defined as P < 0.05. The following variables were analysed as potential confounders: age, sex, ETU, length of ETU operation and date of treatment.

RESULTS

Case fatality was 57.6% among patients diagnosed with EVD. Analysis of case fatality across environmental temperature quintiles indicated a threshold effect; the optimal threshold for average environmental temperature during a patient's ETU stay was determined empirically to be 27.4 °C (81.3 °F). Case fatality was significantly greater for patients with average environmental temperatures above the threshold (70.4%) vs. below (52.0%) (P < 0.001). In multiple regression, patients with average environmental temperature above the threshold during their ETU stay were significantly more likely to die than patients below the threshold (aOR = 2.5, 95% CI 1.6-3.8, P < 0.001). This trend was observed only among patients treated in white tent ETUs, and not in ETUs with aluminium roofs.

DISCUSSION

These findings suggest that an average environmental temperature above 27.4 °C (81.3 °F) during patients' ETU stay is associated with greater risk of death among patients with EVD. Further studies should investigate this effect. These results have potential implications for reducing case fatality through improved ETU construction or other temperature control methods within ETUs during future outbreaks.

A method to reduce heat strain while clad in encapsulating outerwear

The use of personal protective equipment (PPE) increases the risk of heat related maladies. A means to enhance heat dissipation capacity of individuals clad in PPE would be of benefit. The glabrous skin regions of the hands, face, and feet are portals for direct heat transfer between the body core and the external environment. The effects of PPE outerwear and palmar glabrous skin cooling on heat storage were assessed. Subjects engaged in fixed load treadmill exercise in a thermoneutral environment (T_a = 20-24°C) or rested in a hot environment (45 ± 0.5°C). The use of PPE outerwear increased the rate of core temperature rise by five-fold during vigorous exercise. Palm cooling using a stationary water circulation system attenuated the rate of core temperature rise by 30-60% during rest and light, moderate, and vigorous exercise while wearing PPE outerwear. However, the subjects were tethered to the system. A wearable cooling system was devised that allowed free range of motion and unrestricted mobility. The wearable system provided thermal benefits equivalent to the use of the tethering cooling system. With optimization, this wearable cooling technique could neutralize the negative thermoregulatory effects of wearing PPE while engaged in light workload activities such as those encountered by healthcare professionals working in infectious disease treatment centers. For individuals working at higher workloads, such as firefighters, a wearable glabrous skin-based cooling system could extend work bout duration as well as enhance heat loss during episodic recovery periods.

Physiological Evaluation of Personal Protective Ensembles Recommended for Use in West Africa

OBJECTIVE

Personal protective equipment (PPE) provides health care workers with a barrier to prevent human contact with viruses like Ebola and potential transmission of the disease. However, PPE can also introduce an additional physiological burden from potentially increased heat stress. This study evaluated the human physiological and subjective responses to continuous light exercise within environmental conditions similar to those in West Africa while wearing 3 different, commonly used PPE ensembles (E1, E2, and E3).

METHODS

Six healthy individuals were tested in an environmental chamber (32°C, 92% relative humidity) while walking (3 METs, 2.5 mph, 0% incline) on a treadmill for 60 minutes. All subjects wore medical scrubs and PPE items. E1 also had a face shield and fluid-resistant surgical gown; E2 additionally included goggles, coverall, and separate hood; and E3 also contained a highly impermeable coverall, separate hood, and surgical mask cover over the N95 respirator.

RESULTS

Heart rate and core temperature at the end of the exercise were significantly higher for E2 and E3 than for E1. Subjective perceptions of heat and exertion were significantly higher for E2 and E3 than for E1.

CONCLUSIONS

Heat stress and PPE training, as well as the implementation of a work-to-rest ratio that avoids dehydration and possible heat stress issues, are recommended. (Disaster Med Public Health Preparedness. 2017;11:580-586).