key: cord-0802818-3vub58q4
authors: Kim, Sang-Chul; Kong, So Yeon; Park, Gwan-Jin; Lee, Ji-Han; Lee, Joon-Kee; Lee, Moo-Seop; Han, Heon Seok
title: Effectiveness of negative pressure isolation stretcher and rooms for SARS-CoV-2 nosocomial infection control and maintenance of South Korean emergency department capacity
date: 2020-10-01
journal: Am J Emerg Med
DOI: 10.1016/j.ajem.2020.09.081
sha: 6b9d8de4fdfd6ac18d46e6899a53ad8a15f7cf56
doc_id: 802818
cord_uid: 3vub58q4

OBJECTIVE: There are growing concerns regarding the lack of COVID-19 pandemic response capacity in already overwhelmed emergency departments (EDs), and lack of proper isolation facilities. This study evaluated the effectiveness of the negative pressure isolation stretcher (NPIS) and additional negative pressure isolation rooms (NPIRs) on the maintenance of emergency care capacity during the COVID-19 outbreak. METHODS: A before and after intervention study was performed between February 27, 2020 and March 31, 2020 at the ED of Chungbuk National University Hospital, Cheongju, South Korea. A total of 2455 patients who visited the ED during the study period were included. Interventions included the introduction of the NPIS and additional NPIRs in the ED. The main outcome of the study was frequency of medical cessation. Secondary outcomes were the average number of ED visits and lengths of stay. RESULTS: After the intervention, average frequency of medical cessation was significantly decreased from 1.6 times per day (range 0–4) in the pre-intervention period to 0.6 times per day (range 0–3) in the post-intervention period (p-value <0.01). On the other hand, the number of patients visiting the ED increased significantly from 67.2 persons per day (range 58–79) pre-intervention to 76.3 persons per day (range 61–88) post-intervention (p value <0.01). However, there were no statistically significant differences in the average ED length of stay across the study phases (p value = 0.50). CONCLUSIONS: This intervention may provide an effective way to prepare and meet the ED response needs of the COVID-19 pandemic.

On January 20, 2020 the first coronavirus disease 2019 (COVID- 19) case was reported in South Korea. The number of confirmed cases surged within a few weeks, leading to the second largest COVID-19 outbreak, after China, in February. Hence, South Korea has implemented extensive national response strategies including extensive tracing, testing and isolation, and enhanced infection control measures in hospitals to mitigate the transmission of the virus [1, 2] .

While the entire health system is challenged with the response to the COVID-19 pandemic, the emergency department (ED) is a major gateway at the forefront in response to this global emergency [3] . Moreover, besides COVID-19, the ED still needs to provide treatment for patients both infected and critically ill from other diseases. Furthermore, infection prevention is also a major challenge because of the dynamic and high-volume setting of the EDs [4] .

Consequently, there are growing concerns about the lack of capacity and preparedness in the already overwhelmed EDs [5] . Many EDs lack proper isolation facilities, risking spread of the virus to other patients and medical staff, and further limiting ED capacity. [6] National and international COVID-19 guidelines stipulate that for infection prevention, control, and preparedness, healthcare facilities should create a separate area in the ED for the assessment and management of suspected patients presenting with respiratory symptoms [7] [8] [9] . However, a number of asymptomatic cases of COVID- 19 have been reported [10] [11] [12] [13] .

Asymptomatic cases or individuals with mistriage may visit the normal ED area posing the J o u r n a l P r e -p r o o f risk of transmission of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to other patients, visitors, and healthcare workers. Moreover, once mistriage is identified, hospital facilities may be closed for hours for disinfection, causing disruptions in services, and further impairing the already overwhelmed ED capacity.

Therefore, stricter and advanced infection prevention and control practices in healthcare settings, especially in EDs, should be considered. Suspected COVID-19 patients should be screened and treated in negative pressure isolation rooms (NPIRs). However, potential breaches of infection control could occur due to nosocomial spread through intra-hospital patient transfers, especially from asymptomatic patients who need to be transferred to radiology suites for computed tomography (CT) scans [14] .

In order to maximise infection control and ED capacity, we have implemented use of a negative pressure isolation stretcher (NPIS) and additional NPIRs. In this study, we sought to evaluate the effectiveness of the NPIS and NPIRs on our emergency care system in maintaining emergency care capacity (through minimizing medical cessations and maintaining the number of ED visiting patients and ED length of stay) during the COVID-19 outbreak.

This before and after intervention study was performed at the Chungbuk National University Hospital (CBNUH), Cheongju, South Korea. The CBNUH is an 807-bed tertiary-care University Hospital with five NPIRs and approximately 240,000 annual admissions. Since the onset of the COVID-19 outbreak, the CBNUH was designated as one of the twenty-nine national treatment centres in South Korea, for infectious diseases, with over five NPIRs. The J o u r n a l P r e -p r o o f CBNUH ED has been prepared to serve critically ill patients due to COVID-19 while continue providing emergency care for other patients. From February 25 to 27, in response to the COVID-19 outbreak, we remodelled our emergency centre to create a designated isolation area for spatially separating patients presenting with fever or respiratory symptoms.

At the entrance of the hospital, patients were asked if they had 1) close contact with a confirmed case of COVID-19 within the past 14 days, 2), visited countries with active outbreaks of COVID-19 (including China) within the past 14 days, and 3) links to the Shincheonji Church of Jesus in Daegu, a known cluster of infections. Patients who answered yes to any of these questions and presented with fever or respiratory symptoms were directed to the triage room for screening. The triage room was connected to the designated isolation area. If a COVID-19 test was required, a sample was taken in a sample collection room and an X-ray was performed in a radiology room using a mobile X-ray. Patients visiting the ED without fever or respiratory symptoms were screened and treated in the normal ED area.

For ED visiting patients with fever, chest CT was performed to identify the cause and for diagnosis. In the CBNUH, one CT scanner (Revolution TM CT 128; GE Healthcare, USA) is dedicated to the emergency centre. Patients from the designated isolation area who underwent CT imaging or asymptomatic patients from the normal ED area who had CT findings for pneumonia, were considered as suspected COVID-19 cases. Until the results of the COVID-19 tests were confirmed for these patients, the medical staff, including imaging technicians who were in contact with the suspected patients were temporarily quarantined and environmental cleaning and disinfection procedures were conducted, including door handles, registration counters, floors, equipment, CT room, and the ED area. Under the CBNUH J o u r n a l P r e -p r o o f policy, the disinfected areas are ventilated and closed for two hours, which leads to medical cessation.

In cases of mistriage, when asymptomatic patients were screened and treated at the normal ED area but later diagnosed with an unknown cause of pneumonia, the possibility of COVID-19 was considered and COVID-19 tests were performed. While waiting for the test results, the medical staff who were in contact with the mistriaged patients were temporarily quarantined if they had not been fully equipped with personal protective equipment (PPE), and environmental cleaning and disinfection procedures were conducted, followed by two hours of medical cessation.

This study was approved by the Institution Review Board (IRB) of Chungbuk National University Hospital through expediated review with the requirement for informed consent waived (IRB Number: CBNUH 2020-03-035).

Demographic and medical data for patients of all ages who visited the CBNUH emergency centre from February 27 to March 31, 2020 was retrospectively extracted from the hospital electronic medical records and reviewed. All the patients who were screened and treated in either the normal ED or designated isolation area were included. The data included age, sex, date of ED visit, cause of ED visit, level of acuity, mental status, vital signs, radiologic and chemical evaluation, ED disposition, ED results, and ED length of stay. The level of acuity was measured using the Korean Triage and Acuity Scale (KTAS). The KTAS is a five-level triage scale (Level 1 being most severe), which was developed and implemented in all EDs in South Korea since 2015 [15] .

The NPIS (Bio Bag EBV-30/40, EGO Zlin, Ltd, Czech Republic) ( Figure 1A ) was introduced in the CBNUH on March 12, 2020. The isolation stretcher was used to transfer suspected COVID-19 patients requiring CT scans from the designated isolation area to the CT room.

During the scan, patients remained in the NPIS ( Figure 1B ). From March 12 to March 17, hospital staff was trained and adapted to the use of the NPIS (implementation period). During training, an instructor explained on structure (bag and aluminium frame) and components (filtration-ventilation unit and filter) of the NPIS, and methods on how to move a patient into the NPIS and to work the filtration-ventilation unit. Hospital staff also conducted simulation tests on using the NPIS.

In order to increase the ED capacity, we constructed thirteen additional NPIRs. The five existing NPIRs were mainly used for treatment of severe confirmed COVID-19 patients, who were transferred from other medical institutions. The added thirteen NPIRs were mainly used to treat suspected patients from the ED isolation area. When the suspected patient's test result was found to be negative, the quarantine was lifted, and the patient was moved to a general ward or the ICU. The construction of the additional NPIRs was completed and use begun on March 18, 2020.

The main outcome of the study was the frequency of medical cessation. Medical cessation was defined as closure of the entire emergency centre for two hours for the process of disinfection and ventilation after patients from the designated isolation area and asymptomatic patients from the normal ED area were found to be suspected patients.

Secondary outcomes were the average number of ED visits and ED length of stay. The J o u r n a l P r e -p r o o f average number of ED visits were defined as average number of daily ED patients visiting the ED during pre-intervention period, implementation period, and post-intervention period.

The ED length of stay was calculated as the difference between the inflow time and the outflow time of each ED patient, and average ED length of stay was calculated as average ED length of stay (in hours) of all the ED visiting patients in each of the three study phases.

The study consisted of a two-week pre-intervention period (from February 27 to March 11), an implementation period (from March 12 to 17), and a two-week intervention period (from March 18-31). At the start of the intervention period, all the hospital staff were fully informed and had trained/good knowledge of the intervention.

Statistical analyses were performed to compare the demographic and clinical characteristics of the patients and the outcomes (frequency of medical cessation, number of patients admitted/treated in the ED, and ED length of stay) across the three study phases by using appropriate bivariate analysis. Chi-square test was used for categorical variables and Kruskal-Wallis test for continuous variables. All statistical analysis was performed using SAS software (version 9.4; SAS Institute, Inc., Cary, NC).

Of the 2,455 patients included in the study, 941 visited the ED before the intervention, 446 during the implementation period, and 1,068 after the intervention. Of the total ED patients, 1,852 (75.4%) patients were admitted and treated in the main ED area while 603 (24.6%) patients were admitted and treated in the isolation ED area. Figure 2 depicts the trend of the J o u r n a l P r e -p r o o f number of patients treated in the main ED and isolation ED areas, and the daily number of medical cessations during the pre-intervention, implementation, and post-intervention periods.

Demographic and clinical characteristics of all the patients are described in Table 1 . Overall, the median age of the patients who visited the CBNUH ED during the study period was 55 years (IQR: 30-71) and 46.2% were female. The number of patients transferred from and to other hospitals decreased during the post-intervention period from 17.3% to 15.2% for transfer-in (p=0.02) and from 5.1% to 2.4% for transfer-out patients (p<0.01). The median ED length of stay remained unchanged during the study period (3.1 hours). After the introduction of the isolation stretcher, 65 patients were transferred to the CT room and CT scanned in the isolation stretcher (11 patients during the implementation period and 54 patients during the post-intervention period). The number of medical cessations was significantly decreased from 19 times during the pre-intervention period to eight times during the post-intervention period (p-value < 0.01). Fever was the most common cause of medical cessation, followed by pneumonia.

The demographic and clinical characteristics of the 603 patients cared for at the isolation ED area during the study period are outlined in Table 2 

The average frequency of medical cessation was significantly decreased from 1. 

In this before and after study, we observed that the introduction of the NPIS and additional NPIRs in our ED was effective in reducing medical cessations and the number of patients transferring to other hospitals. A greater number of patients was also treated in the ED due to the intervention. There was no difference in the ED length of stay before and after the intervention.

Globally, many healthcare systems have experienced patient numbers exceeding their surge capacities during the COVID-19 pandemic; not only to tend suspected and confirmed COVID-19 cases, but also many patients critically ill from other diseases simultaneously [16, 17] . Of 4,877 ICU clinicians who participated in a Society of Critical Care Medicine survey, 61% were concerned about patient surge and overcrowding during the COVID-19

outbreak [18] . Moreover, in these critical times, there has been temporary closure of emergency rooms in several hospitals globally to perform thorough and extensive terminal J o u r n a l P r e -p r o o f cleaning and disinfection after confirmed COVID-19 cases [19] . Closure of the ED even for a few hours can increase the acute pressure on the ED system after re-opening and hinders the hospitals' operational capability.

RT-PCR tests were performed on all the patients presenting with fever and respiratory symptoms. Additionally, it is essential to perform CT scans to diagnose the cause of the fever.

In our emergency centre, we only have one CT scan that is dedicated to the ED. Therefore, prior to the implementation of the NPIS, whenever a CT scan was performed on a patient from the isolated ED area, the CT room had to be thoroughly decontaminated and closed for two hours. Additionally, when an asymptomatic patient from the normal ED area was later diagnosed with an unknown cause of pneumonia by CT scan, the patient was considered a suspected or confirmed COVID-19 patient and the entire ED area and the CT room had to be decontaminated with ED closure for two hours, causing a medical cessation. During the study period, we had a total of 30 medical cessations with over 63% (19 cases) of them happening during the pre-intervention period. However, after the introduction of the NPIS as a part of our intervention, we observed a significantly reduced number of medical cessations. We believe that as a result of the fewer medical cessations, more patients were treated in our ED and admitted to our hospital. Moreover, extra NPIRs originally constructed to treat COVID-19 confirmed patients, were mainly used to admit and observe suspected COVID-19 patients.

Because of the extra NPIRs, the suspected COVID-19 patients were able to stay and wait for the RT-PCR test result, which takes over six hours, in their NPIRs, instead of staying in the emergency room.

There are a few reported cases of transportation of patients with highly contagious infectious diseases (e.g. SARS and Ebola viruses) using negative isolation transfer equipment in aeromedical [20, 21] and ambulance [22, 23] Our study had several limitations. We only had 14 data points (days) for pre-and postintervention periods. The short intervention period may have skewed our findings and resulted in statistical significance. However, as the COVID-19 was such an emergency both J o u r n a l P r e -p r o o f nationally and internationally, a rapid evaluation of the intervention effect was needed. While more time points before and after the intervention may have provided better understanding and long-term effect of the intervention, we believe that our study results show a meaningful effect of the COVID-19 intervention. Future study is warranted with longer intervention period to have more meaningful and reliable evidence-based recommendation. Another limitation was that we had a comparatively long implementation period (six days). While our hospital had daily COVID-19 Task Force Team meetings, the policy decisions made at the meetings were not effectively communicated to the entire hospital staff, resulting in a long implementation period. Additionally, we implemented two interventions at the same time, therefore were unable to measure the effectiveness of each individual intervention.

In summary, after the introduction of the NPIS and additional NPIRs as a COVID-19 intervention, we observed a notable decrease in the number of medical cessations and an increased number of patients admitted and treated in our ED. As the COVID-19 pandemic is straining healthcare systems globally, this study may provide healthcare providers, hospital administrators, and policy makers an effective way to prepare and meet the response needs of this unprecedented challenge. Table 3 . Effect of the intervention on the main outcomes of the study (average frequency of medical cessation and average number of patients treated during pre-, implementation, and post-intervention periods*). 

Transmission potential and severity of COVID-19 in South Korea

Academic Community's Efforts to Guide the Fight Against Coronavirus Disease 2019 (COVID-19) Epidemic in Korea

The challenge of emergency medicine facing the COVID-19 outbreak

Infection Prevention in the Emergency Department

The impending storm: COVID-19, pandemics and our overwhelmed emergency departments

Covid-19: emergency departments lack proper isolation facilities, senior medic warns

Interim Infection Prevention and Control Recommendations for Patients with Suspected or Confirmed Coronavirus Disease 2019 (COVID-19) in Healthcare Settings n

World Health Organization. Infection prevention and control during health care when COVID-19 is suspected: interim guidance

European Centre for Disease Prevention and Control. Infection prevention and control and preparedness for COVID-19 in healthcare settings: ECDC Technical Report 2020

A familial cluster of pneumonia associated with the 2019 novel coronavirus indicating person-to-person transmission: a study of a family cluster

Transmission of 2019-nCoV Infection from an Asymptomatic Contact in Germany

Asymptomatic cases in a family cluster with SARS-CoV-2 infection

Asymptomatic and Presymptomatic SARS-CoV-2 Infections in Residents of a Long-Term Care Skilled Nursing Facility -King County

Safe patient transport for COVID-19

The Korean Triage and Acuity Scale: associations with admission, disposition, mortality and length of stay in the emergency department

Covid-19 and the Stiff Upper Lip -The Pandemic Response in the United Kingdom

Facing Covid-19 in Italy -Ethics, Logistics, and Therapeutics on the Epidemic's Front Line

Three Covid-19 cases reported at SJMC; ER closed for disinfection

Aeromedical Transfer of Patients with Viral Hemorrhagic Fever

Aerial medical evacuation of health workers with suspected Ebola virus disease in Guinea Conakryinterest of a negative pressure isolation pod-a case series

European concepts for the domestic transport of highly infectious patients

Development of a negative pressure hood for isolation and transportation of individual patient with respiratory infectious disease

SARS: hospital infection control and admission strategies

The Korean Society of Infectious Diseases, and Korean Society for Healthcareassociated Infection Control and Prevention. The Same Middle East Respiratory Syndrome-Coronavirus (MERS-CoV) yet Different Outbreak Patterns and Public Health

We thank the hospital staff and administrators who supported this