BACKGROUND: Owing to shortage of surgical and N95 filtering facepiece respirators (FFRs) during the COVID-2019 pandemic, various masks were developed to prevent infection. This study aimed to examine the inward leakage rate (ILR) of sealed face masks and modified surgical masks using a quantitative fit test and compared it with the ILR of unmodified N95 FFRs. METHODS: We conducted paired comparisons of ILRs of bent nose-fit wire masks, double masks, and N95 FFRs from October to December 2021. To measure the protective effectiveness of masks, participants wore masks, and the number of particles outside and inside the mask were measured. The ILR was based on the percentage of particles entering the mask using a fit tester. RESULTS: We enrolled 54 participants (20 men and 34 women) in this study. The median ILR for surgical masks without and with a W-shaped bend in the nose-fit wire were 96.44% and 50.82%, respectively. The nose-fit wire adjustment reduced the ILR of surgical masks by a mean of 28.57%, which was significantly lower than the ILR without adjustment (P < 0.001). For double masks, with surgical or polyurethane masks on top of the W-shaped mask, the ILR did not differ significantly from that of N95. Although the filtration performance of double surgical masks matched that of N95 masks, their ILR was notably higher, indicating that double masks do not provide equivalent protection. CONCLUSIONS Wearing N95 masks alone is effective in many cases. However, surgical mask modifications do not guarantee consistent effectiveness. Properly selected, sealed masks with a good fit overcome leakage, emphasizing their crucial role. Without evidence, mask-wearing may lead to unexpected infections. Education based on quantitative data is crucial for preventing adverse outcomes.
Male ; Humans ; Female ; N95 Respirators ; COVID-19/epidemiology* ; Masks ; Pandemics/prevention & control* ; Respiratory Protective Devices ; Materials Testing ; Equipment Design ; Occupational Exposure/prevention & control*

INTRODUCTION: During the coronavirus disease 2019 (COVID-19) pandemic, multiple guidelines have recommended videolaryngoscope (VL) for tracheal intubation. However, there is no evidence that VL reduces time to tracheal intubation, and this is important for COVID-19 patients with respiratory failure. METHODS: To simulate intubation of COVID-19 patients, we randomly assigned 28 elective surgical patients to be intubated with either McGrath™ MAC VL or direct laryngoscope (DL) by specialist anaesthetists who donned 3M™ Jupiter™ powered air-purifying respirators (PAPR) and N95 masks. The primary outcome was time to intubation. RESULTS: The median time to intubation was 61 s (interquartile range [IQR] 37-63 s) and 41.5 s (IQR 37-56 s) in the VL and DL groups, respectively ( P = 0.35). The closest mean distance between the anaesthetist and patient during intubation was 21.6 ± 4.8 cm and 17.6 ± 5.3 cm in the VL and DL groups, respectively ( P = 0.045). There were no significant differences in the median intubation difficulty scale scores, proportion of successful intubations at the first laryngoscopic attempt and proportion of intubations requiring adjuncts. All the patients underwent successful intubation with no adverse event. CONCLUSION There was no significant difference in the time to intubation of elective surgical patients with either McGrath™ VL or DL by specialist anaesthetists who donned PAPR and N95 masks. The distance between the anaesthetist and patient was significantly greater with VL. When resources are limited or disrupted during a pandemic, DL could be a viable alternative to VL for specialist anaesthetists.
Humans ; COVID-19 ; Intubation, Intratracheal ; Laryngoscopes ; Laryngoscopy ; Respiratory Protective Devices ; Video Recording

Decontamination ; Disinfection ; Manikins ; Protective Clothing ; Personal Protective Equipment ; Health Personnel

INTRODUCTION: Falls from heights contribute to 34% of fatal accidents in Singapore. Of these, 51% of the accidents occur in the construction industry. This retrospective review, of all persons falling from heights in the construction industry from 2006 to 2012 and attending a major hospital, analysed injury patterns and related them to mechanisms and contributory factors. METHODS: Information collected included injury and casualty characteristics, safety measures, pre-existing medical conditions and clinical outcomes. RESULTS: Of 1,085 patients, 951 were male with a mean age of 39.8 years, mean height of 165.9 cm and mean weight of 69.7 kg. Most of the casualties fell between 0800 and 2000 hours. Among the severely injured patients, 2.4% had head injuries, 54.9% had chest injuries and 39.2% had abdominal and pelvic injuries. For these casualties, the mortality rate was 60.8%. For patients with less than major trauma, the commonest injuries were in the lower limbs (41.8%), upper limbs (40.8%) and spine (22.2%). All the casualties survived. Falls from scaffolding, formwork and platforms were the most common causes of severe injuries (41.1%). Safety helmets and harnesses were reported to be used in 1.8% and 4.1% of instances of falls, respectively. CONCLUSION Studying the patterns of injuries following falls at construction sites has the potential for injury prevention through safe practices, use of safety equipment and targeted training.
Humans ; Male ; Adult ; Female ; Construction Industry ; Craniocerebral Trauma/etiology* ; Protective Devices ; Head Protective Devices ; Retrospective Studies ; Wounds and Injuries/etiology* ; Injury Severity Score

BACKGROUND: Healthcare workers (HCWs) employed personal protective equipment (PPE) during the COVID-19 pandemic, crucial to protecting themselves from infection. To highlight the efficacy of PPE in preventing environmental infection among HCWs, a systematic review was conducted in line with PRISMA guidance. METHODS: A search of the PubMed and Web of Science databases was conducted from January 2019 to April 2021 using pre-defined search terms. Articles were screened by three researchers. The approved papers were read in full and included in this review if relevance was mutually agreed upon. Data were extracted by study design and types of PPEs. RESULTS: 47 of 108 identified studies met the inclusion criteria, with seven reviews and meta-analyses, seven cohort, nine case-control, fifteen cross-sectional studies, four before and after, four case series, and one modeling studies. Wearing PPE offered COVID-19 protection in HCWs but required adequate training. Wearing surgical masks provided improved protection over cloth masks, while the benefit of powered air-purifying respirators is less clear, as are individual gowns, gloves, and/or face shields. CONCLUSIONS Wearing PPE, especially facial masks, is necessary among HCWs, while training in proper use of PPE is also important to prevent COVID-19 infection.
Humans ; COVID-19/prevention & control* ; Pandemics/prevention & control* ; Cross-Sectional Studies ; Personal Protective Equipment ; Health Personnel

Objective: To investigate the wearing of masks and the knowledge of masks among high-risk positions for overseas import and pollution transmission. Methods: From May 14 to 17, 2022, a convenient sampling method was used to conduct an online survey among 963 workers in high-risk positions for overseas import and pollution transmission in Beijing. The behaviors of individual use and wearing masks, the distribution and supervision of the unit, the knowledge of personal mask protection and the subjective feelings of wearing masks were analyzed. The χ(2) test and logistic regression model were used to analyze the influencing factors of the correct selection of masks. Results: The majority of the workers in high-risk positions for overseas import and pollution transmission were male (86.0%, 828/963), age concentration in 18-44 years old (68.2%, 657/963), and the majority of them had college or bachelor degrees (49.4%, 476/963). 79.4%(765/963) of the workers chose the right type of masks, female, 45-59 years old and high school education or above were the risk factors for correct selection of masks (P <0.05). Workers had good behaviors such as wearing/removing masks, but only 10.5% (101/963) could correctly rank the protective effect of different masks. 98.4% (948/963) of the workers believed that their work units had provided masks to their employees, and 99.1% (954/963) and 98.2%(946/963) of them had organized training and supervision on the use of masks, respectively. 47.4%(456/963) of the workers were uncomfortable while wearing masks. Conclusion: The overall selection and use of masks among occupational groups in high-risk positions for overseas import and pollution transmission in China need to be further standardized. It is necessary to strengthen supervision and inspection on the use of masks among occupational groups, and take improvement measures to improve the comfort of wearing masks.
Humans ; Male ; Female ; Adolescent ; Young Adult ; Adult ; Middle Aged ; Cross-Sectional Studies ; Masks ; China ; Surveys and Questionnaires ; Beijing

INTRODUCTION: Countries are mandating the use of face masks to stem the spread of coronavirus disease 2019 (COVID-19). Face mask use has been associated with discomfort due to its effects on thermoregulation, breathing and oxygenation. We evaluated the prevalence and severity of self-reported cardiovascular symptoms before and during face mask use. METHODS: This was a cross-sectional study of 1,001 participants residing in Singapore, who participated in a self-administered questionnaire between 25 April 2020 and 4 May 2020. Symptom severity before and during mask use, and health-seeking behaviour information were collected. The study outcome was self-reported worsening of cardiovascular symptoms and its association with the type of mask worn, duration of mask worn per day, and intensity of physical activities during mask use. RESULTS: The most common symptom reported during mask use was dyspnoea. Independent predictors for self-reported cardiovascular symptoms during mask use were moderate-high physical activity during mask use (odds ratio [OR] 1.634, 95% confidence interval [CI] 1.176-2.270, P = 0.003), duration of mask use for ≥3 h (OR 1.672, 95% CI 1.189-2.352, P = 0.003) and type of mask used, after adjusting for age, sex, healthcare-based worker status and presence of comorbidities. N95 mask was associated with worse symptoms when compared to surgical mask. Participants with ≥3 worsening symptoms or worsening dyspnoea, palpitations, fatigue and dizziness were more likely to seek medical help. CONCLUSION Face mask use has been proven to be an effective way in curbing COVID-19 transmission. However, participants in this study had concerns regarding its use and these concerns should be urgently addressed to enable mask use policies to be enacted.
Humans ; COVID-19/epidemiology* ; Pandemics ; Masks/adverse effects* ; Self Report ; Cross-Sectional Studies ; Dyspnea/etiology*

INTRODUCTION: Laryngeal mask airway (LMA), which is used in difficult airway maintenance conditions during emergencies, is rarely used in prolonged surgery despite its advantages over endotracheal tube (ETT). In this study, we conducted a comparative analysis of intraoperative gas exchanges between second-generation LMA and ETT during prolonged laparoscopic abdominal surgery. METHODS: Prolonged surgery was defined as a surgery lasting more than 2 h. In total, 394 patients who underwent laparoscopic liver resection via either second-generation LMA or ETT were retrospectively analysed. The following parameters were compared between the two groups of patients: end-tidal pressure of carbon dioxide (ETCO₂), tidal volume (TV), respiratory rate (RR), peak inspiratory pressure (PIP), arterial partial pressure of carbon dioxide (PaCO₂), pH and ratio of arterial partial pressure of oxygen to fractional inspired oxygen (PFR) during surgery. In addition, the incidence of postoperative pulmonary complications (PPCs), including pulmonary aspiration, was compared. RESULTS: The values of ETCO₂, TV, RR and PIP during pneumoperitoneum were comparable between the two groups. Although PaCO₂ at 2 h after induction was higher in patients in the LMA group (40.5 vs. 38.5 mmHg, P < 0.001), the pH and PFR values of the two groups were comparable. The incidence of PPC was similar. CONCLUSION During prolonged laparoscopic abdominal surgery, second-generation LMA facilitates adequate intraoperative gas exchange and may serve as an alternative to ETT.
Humans ; Laryngeal Masks ; Carbon Dioxide ; Retrospective Studies ; Intubation, Intratracheal ; Laparoscopy/adverse effects* ; Postoperative Complications/etiology* ; Oxygen

Humans ; Disease Outbreaks/prevention & control* ; Respiratory Tract Infections/epidemiology* ; Personal Protective Equipment ; Disaster Planning ; Singapore

INTRODUCTION: Oropharyngeal swabs for diagnosis of COVID-19 often induce violent coughing, which can disperse infectious droplets onto providers. Incorrectly doffing personal protective equipment (PPE) increases the risk of transmission. A cheap, single-use variation of the face shield invented by a Singaporean team, SG Shield, aims to reduce this risk. This manikin study aimed to study the efficacy of the SG Shield in combination with standard PPE. METHODS: A person attired in full PPE whose face and chest was lined with grid paper stood in front of an airway manikin in an enclosed room. A small latex balloon containing ultraviolet fluorescent dye was placed in the oral cavity of the manikin and inflated until explosion to simulate a cough. Three study groups were tested: (a) control (no shield), (b) face shield and (c) SG Shield. The primary outcome was droplet dispersion, determined quantitatively by calculating the proportion of grid paper wall squares stained with fluorescent dye. The secondary outcome was the severity of provider contamination. RESULTS: The SG Shield significantly reduced droplet dispersion to 0% compared to the controls (99.0%, P = 0.001). The face shield also significantly reduced droplet contamination but to a lesser extent (80.0%) compared to the control group (P = 0.001). Although the qualitative severity of droplet contamination was significantly lower in both groups compared to the controls, the face shield group had more contamination of the provider's head and neck. CONCLUSION The manikin study showed that the SG Shield significantly reduces droplet dispersion to the swab provider's face and chest.
Humans ; Infectious Disease Transmission, Patient-to-Professional/prevention & control* ; COVID-19 ; Fluorescent Dyes ; Personal Protective Equipment ; Cough