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

Objective: To get insight into the current practice of noise reduction effect of workers as they wore hearing protectors in different domestic enterprises and the possible affected factors. Methods: From October 2020 to April 2021, using a random sampling method, 1197 workers exposed to noise in petrochemical factories, textile factories, and parts manufacturing factories were selected as the study subjects. The noise reduction effect of hearing protectors worn by workers in daily use was tested using a hearing protector suitability testing system. The personal sound attenuation level (PAR) was compared among workers in three enterprises, Targeted intervention and repetitive testing were conducted for workers who did not meet the noise reduction effect required by the enterprise, and the changes in PAR of workers before and after the intervention were compared. The comparison of baseline PARs between two or more groups was performed using the Mann Whitney test, the comparison of baseline PARs with post intervention PARs was performed using the Wilcoxon signed rank sum test, and the comparison of qualitative data between two or more groups was performed using the Chi square test. Results: The median baseline PAR for all workers was 15 dB. Men, age<30 years old, education level at or above college level, working experience of 5 to 15 years, and those who used hearing protectors for 5 to 15 years had higher PARs, with statistically significant differences (P<0.05). The median difference in baseline PAR among workers from three enterprises was statistically significant (H=175.06, P<0.01). The median PAR of subjects who did not pass the baseline increased from 3 dB to 21 dB after intervention (Z=-27.92, P<0.01) . Conclusion: Some workers wearing hearing protectors do not meet the required PAR, and low PARs may be related to incorrect wearing methods and incorrect selection of hearing protectors. As a tool for testing, training, and assisting in selection, the hearing protector suitability testing system is of great significance for worker hearing protection.
Male ; Humans ; Adult ; Hearing Loss, Noise-Induced/prevention & control* ; Ear Protective Devices ; Noise, Occupational/prevention & control* ; Hearing ; Audiometry

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

Objective: To explore the occupational protective effect of different protective devices on the operators during manual cleaning and oiling of dental handpieces, and to provide a basis for the selection of appropriate protective methods. Methods: From November 2020 to December 2021, 20 high-speed dental handpieces of the same brand were selected and randomly divided into disposable protective bag group and small aerosol safety cabinet group by drawing lots, with 10 in each group. After recording the model, they were distributed to the clinical fixed consulting room for use, and were collected by specially-assigned personnel every day for manual cleaning under the protection of the two devices. By measuring the number of airborne colonies, the concentrations of particulate matter and the satisfaction of operators, the occupational protection effect of the two protective devices on operators was evaluated. Results: Under the protection of the two devices, the average number of airborne colonies after operation was less than 1 CFU/ml. When no protective device was used, the number concentration of particulate matter produced during operation was (21595.70±8164.26) pieces/cm(3). The number concentrations of particles produced by disposable protective bag group [ (6800.24±515.05) pieces/cm(3)] and small aerosol safety cabinet group [ (5797.15±790.50) pieces/cm(3)] were significantly lower than those without any protective device (P<0.001). The number concentration of particle matter of small aerosol safety cabinet group was significantly lower than that of disposable protective bag group (P<0.001). In the satisfaction evaluation of operators, small aerosol safety cabinet group [ (3.53±0.82) points] was significantly better than disposable protective bag group [ (2.23±1.10) points] (P<0.001) . Conclusion: The use of small aerosol safety cabinet during manual cleaning and oiling of dental handpieces has good protective effect, superior safety performance and strong clinical applicability, and has advantages in occupational protection of clinical operators.
Aerosols ; Particulate Matter ; Protective Devices

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

INTRODUCTION: Wheeled recreational devices (WRDs) include tricycles, bicycles, scooters, inline skates, skateboards, longboards and waveboards, and can cause significant morbidity and mortality. This study aimed to describe the epidemiology and nature of injuries sustained by children from WRD use, and risk factors for severe injury. METHOD: We described injuries relating to WRD use in children <18 years who presented to the emergency department of an Asian tertiary hospital between 2016 and 2020. Demographic data, site and nature of the injury, and historical trends were analysed. Risk factors for severe injury (defined as fractures or dislocations), Injury Severity Score ≥9, and injuries resulting in hospitalisation, surgery or death were evaluated. RESULTS: A total of 5,002 patients with 5,507 WRD-related injuries were attended to over the 5-year study period. Median age was 4.7 years. Injuries related to bicycles (54.6%) and scooters (30.3%) were most frequent, followed by skateboards and waveboards (7.4%), inline skates (4.7%), and tricycles (3.0%). Injuries occurred most frequently in public spaces. Soft tissue injuries (49.3%) and fractures (18.7%) were the most common diagnoses. Upper limb (36.4%) and head and neck (29.0%) regions were the most common sites of injury. Among the patients, 1,910 (38%) had severe injuries with potential morbidity. On multivariate analysis, heavier children of the school-going age who use either scooters, skateboards or inline skates are more prone to severe injuries. Involvement in a vehicular collision was a negative predictor. CONCLUSION WRD use in children can result in severe injuries. Wrist and elbow guards, as well as helmets are recommended, along with adequate parental supervision.
Child ; Child, Preschool ; Emergency Service, Hospital ; Fractures, Bone/etiology* ; Head Protective Devices ; Humans ; Injury Severity Score ; Retrospective Studies ; Risk Factors ; Singapore/epidemiology*