The airflow distribution and aerosol diffusion rules in the negative pressure isolation ward

Negative pressure wards are significant in preventing the spread of infectious pathogens which play a crucial role in fighting against COVID-19. Owing to the negative pressure, contaminated air with pathogens is not able to flow from the wards to non-contaminated zones while fresh filtered air will be transported to the ward via the ventilation system. As airflow controlled by ventilation systems affects the motion of pathogens, for example, infectious aerosol particles, the ability of a negative pressure ward to reduce the risk of infection highly relies on an effective ventilation system. In this investigation, impacts of airflow patterns under various human postures and ventilation processes aerosols diffusion are analyzed via the computational fluid dynamics (CFD) simulation. According to the results, among three airflow patterns, the highest contaminant removal efficiency is 57% at 200 s with the top supply and bottom return mode;besides, in three postures, in the case that the patient is in a standing position, the contaminant removal efficiency is the highest. Furthermore, it is found that the best airflow scheme is a slit tuyere in the ward, with a top supply and side return mode and a sitting position for the patient. This study may provide a reference for the design of airflow in negative pressure isolation wards, control of contaminants, and prevention of viral infections, so as to ensure a good working and recovery environment for medical staff and patients. [ FROM AUTHOR] Copyright of Simulation is the property of Sage Publications, Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

Why do ventilation strategies matter in controlling infectious airborne particles? A comprehensive numerical analysis in isolation ward

A proper ventilation strategy in an isolation ward could promote better indoor air quality for the occupants. This could also reduce the risk of immunocompromised patients contracting healthcare-associated infections (HAI) or airborne diseases such as COVID-19, tuberculosis, and measles among others. This study aims to propose and examine appropriate ventilation strategies in a single-patient isolation ward that can reduce particle settlement in patients. A simplified CFD model of the isolation ward was developed and well-validated against established data. An RNG k-ε model and discrete phase model (DPM) were used to simulate airflow and particle transportation. The study examined the airflow and particle dispersion under a baseline case and four proposed ventilation strategies. Results showed that the baseline case study, which used the ceiling-mounted air curtain was insufficient to prevent the particles from dispersing into the vicinity of the patient. Likewise, the dilution effect under the baseline case and case 4 (wall-mounted air supply diffuser) were relatively weak due to the low air change rate (ACH) of 4/hr and 9/hr respectively. The ventilation strategy in case 4 has a negligible effect on reducing the particles (14%) settling on the patient although the ACH in case 4 was 2-times the baseline case. The present finding ascertains that utilising the combination of ceiling-mounted air diffuser and air curtain jet (case 3) results in zero particle settlement on both patient's and the patient's bed. It also reduced 57% of particles in the vicinity of the medical staff's breathing zone compared to the baseline case. © 2023 Elsevier Ltd

Why do ventilation strategies matter in controlling infectious airborne particles? A comprehensive numerical analysis in isolation ward

A proper ventilation strategy in an isolation ward could promote better indoor air quality for the occupants. This could also reduce the risk of immunocompromised patients contracting healthcare-associated infections (HAI) or airborne diseases such as COVID-19, tuberculosis, and measles among others. This study aims to propose and examine appropriate ventilation strategies in a single-patient isolation ward that can reduce particle settlement in patients. A simplified CFD model of the isolation ward was developed and well-validated against established data. An RNG k-ε model and discrete phase model (DPM) were used to simulate airflow and particle transportation. The study examined the airflow and particle dispersion under a baseline case and four proposed ventilation strategies. Results showed that the baseline case study, which used the ceiling-mounted air curtain was insufficient to prevent the particles from dispersing into the vicinity of the patient. Likewise, the dilution effect under the baseline case and case 4 (wall-mounted air supply diffuser) were relatively weak due to the low air change rate (ACH) of 4/hr and 9/hr respectively. The ventilation strategy in case 4 has a negligible effect on reducing the particles (14%) settling on the patient although the ACH in case 4 was 2-times the baseline case. The present finding ascertains that utilising the combination of ceiling-mounted air diffuser and air curtain jet (case 3) results in zero particle settlement on both patient's and the patient's bed. It also reduced 57% of particles in the vicinity of the medical staff's breathing zone compared to the baseline case.

Recommendations for ventilation of remodeled negative-pressure isolation wards for COVID-19 patients: A comparison of international guidelines.

This mini-review provides the practice guideline recommendations for ventilation of remodeled negative-pressure isolation wards for COVID-19 Patients. Remodeled "quasi-negative-pressure" isolation wards had been proved a feasible, inexpensive, safe, and effective measure to contain nosocomial outbreaks. We should first determine the minimum required ventilation volume of an isolation ward based on the severity of COVID-19 patients. Mechanical ventilation remains the mainstay for achieving the requirement, while the assistance of recirculation is also helpful. Beyond adequate ventilation volume, the "clean to less-clean" directional airflow remains the golden rule for the solution of indoor ventilation. The virus-laden exhaust should be treated with HEPA/UV device or be kept away from living organisms, buildings, and air inlets.

Distribution of droplets/droplet nuclei from coughing and breathing of patients with different postures in a hospital isolation ward.

Suspected and confirmed cases of infectious diseases such as COVID-19 are diagnosed and treated in specific hospital isolation wards, posing a challenge to preventing cross-infection between patients and healthcare workers. In this study, the Euler-Lagrange method was used to simulate the evaporation and dispersion of droplets with full-size distribution produced by fluctuating coughing and breathing activities in an isolation ward. The effects of supply air temperature and relative humidity, ventilation rates and patient postures on droplet distribution were investigated. The numerical models were validated by an aerosol experiment with an artificial saliva solution containing E. coli bacteria conducted in a typical isolation ward. The results showed that the small size group of droplets (initial size ≤87.5 µm) exhibited airborne transmission in the isolation ward, while the large size group (initial size ≥112.5 µm) were rapidly deposited by gravitational effects. The ventilation rate had a greater effect on the diffusion of droplet nuclei than the supply air temperature and relative humidity. As the air changes per hour (ACH) increased from 8 to 16, the number fraction of suspended droplet nuclei reduced by 14.2% and 6.4% in the lying and sitting cases, respectively, while the number fraction of escaped droplet nuclei increased by 16.2% and 14.6%. Regardless of whether the patient was lying or sitting, the amount of droplet nuclei deposited on the ceiling was highest at lower ventilation rates. These results may provide some guidance for routine disinfection and ventilation strategies in hospital isolation wards.

Droplet aerosols transportation and deposition for three respiratory behaviors in a typical negative pressure isolation ward.

Negative pressure isolation wards could provide safety for health care workers (HCWs) and patients infected with SARS-CoV-2. However, respiratory behavior releases aerosols containing pathogens, resulting in a potential risk of infection for HCWs. In this study, the spatiotemporal distribution of droplet aerosols in a typical negative pressure isolation ward was investigated using a full-scale experiment. In this experiment, artificial saliva was used to simulate the breathing behavior, which can reflect the effect of evaporation on droplet aerosols. Moreover, numerical simulations were used to compare the transport of droplet aerosols released by the three respiratory behaviors (breathing, speaking, and coughing). The results showed that droplet aerosols generated by coughing and speaking can be removed and deposited more quickly. Because reduction in the suspension proportion per unit time was much higher than that in the case of breathing. Under the air supply inlets, there was significant aerosol deposition on the floor, while the breathing area possessed higher aerosol concentrations. The risk of aerosol resuspension and potential infection increased significantly when HCWs moved frequently to these areas. Finally, more than 20% of the droplet aerosols escaped from the ward when the number of suspended aerosols in the aerosol space was 1%.

A Novel Smart Hospital for Isolation of COVID-19 Patients

In this paper we describe a smart and innovative system which provides prime contribution to our society in this pandemic situation. We propose a novel smart hospital with multi featured equipments along with fashionable isolation ward for COVID-19 patients. A website interface has been proposed under anyone can visit and after knowing the status of the beds either for the isolation or emergency ward they can easily book from remote location. A QR code with registration number will be provided to the users. These users may reach to the hospital and have to pass through the QR code scanner for verification and sanitization process. A preevaluation section has been defined where proper mask at face will be detected with thermal scanner facility. All the designed section is controlled and monitor by control unit through server. Well featured with multiple sensors a unique ward is designed where oxygen level sensor is used to sense the level of oxygen and if the level of oxygen of patient is less than defined value supply of oxygen will switch on the supply automatically. Doctor will monitor and take care of patients through CCTV and video conferencing. The entire sub design unit is controlled and monitored via hybrid network and IoT. © 2021 IEEE.

The influence of air supply inlet location on the spatial-temporal distribution of bioaerosol in isolation ward under three mixed ventilation modes

The outbreak of COVID-19 and the spread of infectious pathogens through bioaerosols have once again aroused widespread concern worldwide. Isolation ward is an important place to prevent the spread of infectious bioaerosols. However, infection of health care workers (HCWs) in the isolation ward often occurs, so it is urgent to carry out relevant research to reduce the cross-infection between HCWs and patients. In this paper, the temporal and spatial distribution characteristics of bioaerosols under three mixed ventilation modes in a single ward were studied, namely, upper supply side return air of Case 1 and side supply and side return ventilation are Case 2 and Case 3 respectively. The results show that the removal efficiency of bioaerosol in the ventilation mode of Case 3, in which directional airflow is formed from the air supply inlet to the release source and then to the exhaust outlet, is 46.6% and 67.7% higher than that of Case 1 and Case 2, respectively. In addition, ventilation methods based on mixed theory do not guarantee good air quality in the breathing zone (1.3m to 1.7m) of HCWs, which may increase the inhalation risk for HCWs. It is hoped that our results can provide some useful suggestions for optimizing the airflow layout of the isolation ward, reducing the risk of cross-infection, and virus elimination.

Establishment of an effective nursing team against COVID-19-a COVID-19 treatment center experience.

BACKGROUND: Novel coronavirus disease 2019 (COVID-19) is a serious infectious respiratory disease widespread worldwide. Nurses are the front-line staff in contact with infected patients and play a key role in treating patients and controlling the epidemic. The purpose of this study was to share our nursing team's experience in the treatment of COVID-19 and provide clinical guidance. METHODS: Detail nursing system arrangement was laid down: (I) reasonable division of ward channel was built; (II) effectively arranged human nursing resources and establishing special groups, including Training group, Critical patients nursing group, Quality control group, Epidemic preventive measures group, and Logistics support group; (III) optimize nursing workflow and establish various rules and regulations; (IV) scientific scheduling and humanized management; (V) pay attention to psychological support and adopt humanized management. The pre-job preparation, treatment results, and medical staff infection number were recorded. RESULTS: Fifty-four intensive care nurses all passed the training with an average score of 99.75±0.13. One patient was dead, and 22 patients were discharged smoothly. The average length of stay was 9.12 days. The medical staff was not infected. CONCLUSIONS: The treatment center was set up and functioning rapidly, safely, and orderly by implementing an emergency management strategy. The goal of a high rescue rate, low mortality, and no medical staff infection was achieved. This nursing system could be applied in COVID-19 patient treatment.

Using Mindfulness to Reduce Anxiety and Depression of Patients With Fever Undergoing Screening in an Isolation Ward During the COVID-19 Outbreak.

The coronavirus disease 2019 (COVID-19) continues to spread globally. This infectious disease affects people not only physically but also psychologically. Therefore, an effective psychological intervention program needs to be developed to improve the psychological condition of patients screened for fever during this period. This study aimed to investigate the effect of a brief mindfulness intervention on patients with suspected fever in a screening isolation ward awaiting results of the COVID-19 test. The Faces Scale and the Emotional Thermometer Tool were used to investigate 51 patients who were randomly divided into an intervention group and a control group. All patients completed self-rating questionnaires online at the time they entered the isolation ward and before they were informed of the results. The intervention group listened to the mindfulness audios through hospital broadcasts in the isolation ward before their lunch break and while they slept. Compared with the control group, the intervention group's life satisfaction score increased (F = 4.02, p = 0.051) and the emotional thermometer score decreased (F = 8.89, p = 0.005). The anxiety scores (F = 9.63, p = 0.003) and the needing help scores decreased significantly (F = 4.95, p = 0.031). Distress (F = 1.41, p = 0.241), depression (F = 1.93, p = 0.171), and anger (F = 3.14, p = 0.083) also decreased, but did not reach significance. Brief mindfulness interventions can alleviate negative emotions and improve the life satisfaction of patients in the isolation ward who were screened for COVID-19 during the waiting period.

Development and application of quality checklist for the prevention and control of COVID-19 in fever clinic and isolation ward of the general hospital.

To develop a quality control checklist for the prevention and control of coronavirus disease 2019 （COVID-19） in fever clinic and isolation ward of the general hospital and to assess its application. Based on the relevant prevention and control plans and technical guidelines for COVID-19，Delphi method was used to identity items for evaluation，and a quality control checklist for the prevention and control of COVID-19 in the fever clinic and isolation ward was developed in Sir Run Run Shaw Hospital. The checklists included 8 dimensions and 32 items for fever clinic，7 dimensions and 27 items for the isolation ward. The appointed inspectors conducted daily quality control for each shift with this checklist. The expert authority coefficient was 0.88，the mean of the importance of each index in the quality control table was not less than 4.8，and the coefficient of variation was not more than 0.07. During the entire February 2020，8 problems were found and rectified on-the-spot with the application of the checklist. Quality inspection rate was 100% in both isolation wards and fever clinic. The compliance rate and accuracy rate of hand hygiene were 100%; the correct rate of wearing and removing protective equipment increased from 96% to 100%. During the same period，a total of 1915 patients were admitted to the fever clinic，including 191 suspected patients （all were isolated in the hospital，3 were confirmed）. There were no medical staff infected with COVID-19，no cross infection of patients and their families in the hospital. A quality control checklist for the prevention and control of COVID-19 has been developed and applied in the isolation wards and fever clinic，which plays an important role in preventing nosocomial infection.

The impact of age on anxiety in Covid-19 patients in quarantine wardwards.

This study aimed to explore which age group out of the patients in quarantine wards with novel coronavirus pneumonia is the most susceptible to anxiety. The data of 32 Covid-19 patients isolated in the quarantine wards of the second Infectious Diseases Department of Baoding Hospital and 71 Covid-19 patients in Tangshan City Infectious Disease Hospital from January 24th to March 5th, 2020, a total of 103 patients, were analyzed. Among these patients, 97 isolated patients were scored with a self-rating anxiety scale (SAS) score seven days after quarantine, and the correlation between age and score was analyzed. These 97 isolated patients were then divided into three groups according to age: group A (up to 35 years old), group B (36-60 years), and group C (over 60 years). One-way analysis of variance was used to compare the scores among groups. The Q-test was used for pairwise comparison.P < 0.05 was considered statistically significant.There was a negative correlation between age and SAS score in isolated Covid-19 patients, and the differences in the score among groups were statistically significant. Patients under 35 years old were more prone to anxiety when they were isolated for seven days. Isolated patients aged up to 35 years old need more attention from quarantine medical staff, communication should be strengthened, and psychological intervention from psychotherapists should be given if necessary.

Sources of Care Stress of Nursing Staff for Patients with Infectious Diseases during the Prevalence of COVID-19: A Case Study of Some Regional Teaching Hospitals in Southern Taiwan.

(1) Background: The COVID-19 epidemic had caused more than 100 million confirmed cases worldwide by the end of January 2021. The focus of this study was to explore which stress was felt the most by nursing staff in isolation wards in the face of dangerous infectious diseases. (2) Methods: Nursing staff in negative pressure isolation wards were taken as the research objects. The sources of stress were divided into 14 items in three categories, namely, patient care, infection protection, and support system, and the questionnaire results were ranked by a Gaussian curve. (3) Results: Even during the COVID-19 epidemic, nurses in isolation wards still consider that the clinical symptoms of patients in isolation wards cannot be closely tracked as the primary consideration. (4) Conclusions: During the epidemic period, the ability and confidence of nursing staff were strengthened through education and training, and their chances of infection were reduced through comprehensive vaccination and the improvement of protective equipment. In the face of the unstable mood of patients and their families due to isolation, more protective measures should be prepared for nursing staff. In order to relieve the stress, supervisors can adjust the nursing manpower timely according to the difficulty and risk of patient care to reduce the care stress.

SWOT Analysis and Preliminary Study on Prevention and Control Management of Temporary Integrated Isolation Ward During COVID-19 Outbreak.

Background: The world faced crises of prevention and control and shortage of medical resources during the COVID-19 (Corona Virus Disease 2019) outbreak. The establishment of temporary integrated isolation wards in hospitals, which is universal and representative in China, is one of the most-effective strategies in solving these problems according to China's experiences. Aim: To conduct a preliminary study on the establishment of a temporary integrated isolation ward during the outbreak of COVID-19 and to evaluate related impact. Methods: SWOT analysis was used to analyze the advantages, disadvantages, opportunities, and risks in the establishment of the temporary integrated isolation ward, and corresponding corrective measures were made according to the analysis results. Findings: The ward has formulated more than 10 related work procedures and prevention and control measures. A total of 93 patients with 18 critically ill patients were admitted for treatment and isolation. They were all evaluated based on established procedures and protocols. Twenty-four supplementary nucleic acid tests were ordered and conducted. One new patient with COVID-19 was confirmed and was successfully transferred to the designated COVID-19 infectious control hospital. There were no missed diagnosis or misdiagnosis, no cross-infection of patients, no cluster outbreak, and no infection of medical workers during the entire process. Conclusion: SWOT analysis is helpful in guiding the establishment of a temporary integrated isolation ward and the formulation of prevention and control measures in Hebei General Hospital during the COVID-19 outbreak. It provides the guidance and reference of significance for the establishment of similar types of wards in the future.

The Effect of Staggered Shift Scheduling Mode on Nurses in the COVID-19 Isolation Ward- A Cross Sectional Study.

In order to explore the rational use of nursing resources in the epidemic situation of COVID-19, we optimized the shift arrangement in COVID-19 isolation area and constructed a reasonable nursing schedule under the condition of limited human resources. Seventy-eight nurses were arranged in COVID-19 isolation area to work for 1 week according to 3 different shifts: 4 + 4 h, 6 h and 6 h (overlapping by 1 h). Through the form of questionnaire, the comprehensive job satisfaction of 3 different models were compared, and the nursing quality and the consumption of protective equipment under 3 different modes were analyzed. The results showed that the comprehensive job satisfaction and nursing quality of nurses in 6 h (overlapping by 1 h) shift mode were better than those in other shift modes, and the consumption of protective equipment was lower.

Adaptive Wall-Based Attachment Ventilation: A Comparative Study on Its Effectiveness in Airborne Infection Isolation Rooms with Negative Pressure.

The transmission of coronavirus disease 2019 (COVID-19) has presented challenges for the control of the indoor environment of isolation wards. Scientific air distribution design and operation management are crucial to ensure the environmental safety of medical staff. This paper proposes the application of adaptive wall-based attachment ventilation and evaluates this air supply mode based on contaminants dispersion, removal efficiency, thermal comfort, and operating expense. Adaptive wall-based attachment ventilation provides a direct supply of fresh air to the occupied zone. In comparison with a ceiling air supply or upper sidewall air supply, adaptive wall-based attachment ventilation results in a 15%-47% lower average concentration of contaminants, for a continual release of contaminants at the same air changes per hour (ACH; 10 h-1). The contaminant removal efficiency of complete mixing ventilation cannot exceed 1. For adaptive wall-based attachment ventilation, the contaminant removal efficiency is an exponential function of the ACH. Compared with the ceiling air supply mode or upper sidewall air supply mode, adaptive wall-based attachment ventilation achieves a similar thermal comfort level (predicted mean vote (PMV) of -0.1-0.4; draught rate of 2.5%-6.7%) and a similar performance in removing contaminants, but has a lower ACH and uses less energy.

An Experience of Otorhinolaryngologists as Frontline Worker with Novel Coronavirus: A Qualitative Analysis.

During this COVID pandemic healthcare worker systems were overwhelmed. Doctors especially otorhinolaryngologists in addition to doing their specialty duty were also recruited to provide care to COVID-19 patients. To our knowledge, no studies about their experiences regarding COVID-19 have been published. Present study aimed to describe the experiences of Otorhinolaryngologist during this pandemic. This is a qualitative study using an empirical phenomenological approach. 30 ENT doctors were recruited from government and private sector. They participated in semi-structured, in-depth interviews by telephone in a period of one month. Interviews were recorded by consent and data was analyzed. After analysis four themes were revealed namely; 'nature of duty during Covid-19 pandemic', 'modification made to adjust the duty', 'conflict between professional duty and family responsibilities', and 'fear of pandemic ill effect on their health'. The extreme work and fatigue drained ours ENT doctor's physically as well as emotionally. But our doctors showed their resilience and the spirit of professional dedication to overcome difficulties. Comprehensive support should be provided to safeguard the wellbeing of health-care providers mainly doctors. In the meantime timely as well as intensive training for all healthcare worker is highly recommended to promote preparedness and improve efficacy during the pandemic.

COVID-19 Epidemic: Clinical Characteristics of Patients in Pediatric Isolation Ward.

In order to accurately admit children with COVID-19 to an isolation ward, our study retrospectively analyzed the clinical characteristics of children in isolation wards during the COVID-19 epidemic. It was found that 55 cases (83.3%) had fever and 48 cases (72.7%) coughed in the isolated area, 31 cases (47%) had a history of exposure, 26 cases (39.4%) had a decrease in lymphocytes (LYM), more than half had an increase in lactate dehydrogenase and creatine kinase isoenzyme, 14 cases (21.2%) had positive SARS-CoV-2 nucleic acid, 58 cases (87.9%) had abnormal chest computed tomography (CT), and 11 cases (16.7%) had sinus arrhythmia. Therefore, for some suspected children with COVID-19, we can make a comprehensive judgment through clinical symptoms, epidemiological history, LYM number, myocardial enzyme spectrum, chest CT, and electrocardiogram; put these children in an isolation ward for treatment; and then transfer them to a general ward for treatment after excluding COVID-19.

[Infection prevention and control of bedside blood purification treatment in patients with COVID-19].

OBJECTIVE: To explore the infection prevention and control strategy of bedside blood purification treatment in corona virus disease 2019 (COVID-19) isolation ward, and to evaluate the effect of infection prevention and control management measures. METHODS: We summarized and analyzed the clinical features, infection status, outcome and infection prevention and control measures of bedside blood purification treatment patients in COVID-19 isolation ward from February 8, 2020 to March 31, 2020, analyzed the COVID-19 cross-infection between the patients and medical staffs, and the blood-borne pathogens cross-infection situation between the patients, and analyzed the effect of bundle prevention and control measures in controlling the occurrence and spread of cross-infection. RESULTS: A total of 101 COVID-19 patients were hospitalized in this COVID-19 isolation ward, of whom 10 patients (9.90%) received bedside blood purification treatment and the blood purification treatment method was continuous hemodialysis filtration (CVVHDF), and the 10 patients received 79 times of blood purification treatment in total. The prevention and control management measures adopted included divisional isolation, patient behavior isolation and patient placement, operator personal protection and hand hygiene, dialysis waste fluid disposal, isolation room air purification, object surfaces, medical devices and medical fabrics dis-infection management. There were no occurrence and spread of COVID-19 in the medical healthcare workers and blood-borne pathogens cross-infection in the patients. And all the twice throat swabs (two sampling interval > 1 day) of the medical staffs in COVID-19 virus nucleic acid test were negative. The 2 suspected COVID-19 patients' throat swab virus nucleic acid test and the COVID-19 IgG, IgM were always both negative, the chest CT showed no viral pneumonia. CONCLUSION: Bedside blood purification treatment in the COVID-19 isolation ward, the occurrence and spread of healthcare associated infection can be effectively controlled through effective infection prevention and control management, including divisional isolation, patient behavior isolation and patient placement, operator personal protection and hand hygiene, dialysis waste fluid disposal, isolation room's air purification, object surfaces, medical devices and medical fabrics disinfection, which can provide experience for diagnosis, treatment and prevention and control of patients in the respiratory infectious disease ward.