Buffer wards for the control of COVID‐19 transmission in hospitals

Abstract

To the Editor:The outbreak of the coronavirus disease 2019 (COVID‐19) has brought great challenges to the routine diagnosis and treatment of patients. 1 It has been proved in our clinical practice that the buffer ward, as the intermediate platform of pre‐examination and risk screening for patients requiring hospitalization, was an effective way to control the COVID‐19 transmission in hospitals. 2 However, limited literatures reported the operation and efficiency of the buffer ward. We therefore summarized the admission, characteristics, and outcomes of the patients in buffer wards in our hospital.A total of 1003 patients were included (median age 57 years [interquartile range, IQR, 48–65; range 2–95 years]; 49.5% female; 36.0% cancer) between March 11 and April 23, 2020 (Table 1). Cancer patients, who were vulnerable to COVID‐19, were also the focus of this study. Subgroup analyses were performed between cancer and noncancer patients. The demographic distribution between two groups was well balanced (median age 57 years [IQR 50–64; range 3–88 years] and 51.3% female vs median age 57 years [IQR 47–67; range 2–95 years] and 48.4% female; P = .68 for age and P = .39 for gender). Among all the 361 cancer patients, those with thoracic tumors (98, 27.2%), mainly lung cancer, have the most urgent need for hospitalization, followed by gastrointestinal tumors (67, 18.6%) and breast cancer (56, 15.5%) (Table 1). Among the 642 noncancer patients, those with chronic cardio‐cerebrovascular diseases (115, 31.2%) were the most affected population, which mirrors findings of other literatures. 3 , 4 In addition, 19 (3.0%) patients were admitted for thrombotic disease, reflecting the inevitable reality of limited social activities under the epidemic. 5 TABLE 1Baseline characteristics of patients hospitalized in buffer wardsClinical characteristicsNumber (%)Total number1003Age (years), median (IQR) [range]57 (48‐65) [2‐95]SexFemale496 (49.5)Male507 (50.5)Cancer361 (36.0)Age (years), median (IQR) [range]57 (50‐64) [3‐88]SexFemale185 (51.3)Male176 (48.8)SubcategoriesHead and neck cancer38 (10.5)Thoracic cancer98 (27.2)Digestive cancer67 (18.6)Breast cancer56 (15.5)Female genital cancer49 (13.6)Male genitourinary cancer17 (4.7)Lymphatic hematopoietic cancer28 (7.8)Endocrine cancer3 (0.8)Bone and soft tissue cancer3 (0.8)Skin cancer2 (0.6)Noncancer642 (64.0)Age (years), median (IQR) [range]57 (47‐67) [2‐95]SexFemale311 (48.4)Male331 (51.6)SubcategoriesCardiovascular disease75 (11.7)Respiratory disease23 (3.6)Digestive disease61 (9.5)Hematological disease21 (3.3)Breast and thoracic surgery disease40 (6.2)Cerebrovascular and neurological disease125 (19.5)Interventional and vascular surgery disease19 (3.0)Head and neck and otolaryngological disease17 (2.7)Kidney disease a 62 (9.7)Urologic disease59 (9.2)Liver disease b 12 (1.9)Orthopedic disease47 (7.3)Ophthalmic disease36 (5.6)Gynecological disease35 (5.5)Metabolic disease6 (0.9)Psychiatric disease4 (0.6) Note. Data are presented as absolute numbers and percentages (%) or median (IQR) [range]. χ 2 test and one‐way ANOVA were used for comparative analyses between the two subgroups of patients in terms of sex and age, respectively, by SPSS24.0 software.Abbreviation: IQR, interquartile range.aAssessed based on a diagnosis of acute and chronic kidney disease in medical history by International Statistical Classification of Diseases and Related Health Problems, 11th Revision (ICD‐11) coding.bAssessed based on a diagnosis of infectious, drug‐induced, or toxic liver disease in medical history by ICD‐11 coding.John Wiley & Sons, Ltd.The process of hospitalization and risk stratification of COVID‐19 is shown in Figure 1. All patients would undergo two rounds of risk screening in outpatient and emergency department and buffer ward, respectively. Patients with confirmed infection would be reported immediately and sent to designated hospitals, meanwhile the suspicious close contacts would be isolated for another 14‐day quarantine.FIGURE 1Hospitalization and risk stratification strategy of COVID‐19 for patients during the epidemic remission stage. At the beginning of the outbreak, the epidemic was controlled mainly through designated hospitals and mobile cabin hospitals, whereas in the remission stage, the main strategy was to maintain stability by screening of asymptomatic individuals and setting up buffer wards. The first round of risk screening in outpatient or emergency department includes chest CT scan, blood routine, and virological tests (nucleic acid test of nasopharyngeal and oropharyngeal swab and serological test of IgM and IgG antibody). Unconfirmed asymptomatic patients were temporarily transferred to buffer ward for a second round of screening, including blood routine, nucleic acid tests of nasopharyngeal, oropharyngeal, sputum, and anal swabs, and serological tests of IgM and IgG antibody. Other specialized examinations may also be conducted if necessary, such as cardiac troponin I (cTnI) and craniocerebral CT scan. The three zones and two channels of buffer wards refer to the clean zone, potential contaminated zone, contaminated zone, medical personnel channel, and patient channel. The buffer wards were classified into subspecialties: (1) comprehensive surgical buffer ward, (2) comprehensive internal medicine buffer ward, (3) buffer ward for breast, thyroid and reproductive system diseases, (4) buffer ward for gastrointestinal bleeding or other emergencies, (5) oncology and hematology buffer ward, (6) ophthalmic buffer ward, (7) psychiatric buffer ward, and so onAs an important gateway to control the epidemic in hospitals, the buffer ward was temporarily constructed based on the principle of three zones and two channels, and was under closed‐end management to reduce the nosocomial cross‐infection (Figure 1). Specialist consultation became the bridge of communication. A standard two‐ or six‐occupant ward can only accommodate a maximum of one or two patients, respectively, and those previously infected patients must be admitted to a separate ward. To improve efficiency and save medical resources, we classified buffer wards into subspecialties for centralized management of similar patients.It was reported that the viral load of asymptomatic patients was no less than that of symptomatic patients. 8 Close monitoring and preventing them from gathering remains the priority. Three months ago, the Wuhan Health Committee had organized the nucleic acid test of COVID‐19 for nearly 10 million residents, and only 300 (0.003%) asymptomatic infected individuals were eventually detected. In our study, the asymptomatic infection rate of hospitalized patients was relatively higher, at 3.8% (Table 2). And of the 38 asymptomatic infected patients, two developed a confirmed infection. Among all admitted patients, only one newly confirmed and one re‐positive cases were found. Of all the nine close contacts, none has developed symptoms or confirmed to be infected after rigorous medical observation (Table 2). Therefore, despite relatively high density of asymptomatic individuals in hospitals, the transmission of the virus was effectively blocked, and that is maybe what the buffer wards were for.TABLE 2Laboratory and virological analysis of patients hospitalized in buffer wardsNo. (%)IndicatorsCancer patientsNoncancer patientsReference ranges P‐valueTemperature, >37.3°C5 (1.4)24 (3.7).03 a Chest CT, viral pneumonia imaging0 (0.0)5 (0.8).09Length of stay, a >3 days33 (9.1)39 (6.1).07Lymphopenia, <1.1 × 109/L115 (31.9)156 (24.5).01 a Laboratory indicators, median (IQR) [No.]WBC (absolute count, × 109/L)6.1 (4.8‐7.9) [361]6.6 (5.2‐8.4) [639]3.5‐9.5>.99NEU3.8 (2.8‐5.5) [361]4.3 (3.1‐5.8) [636]1.8‐6.3>.99NEU%65.6 (57.6‐73.1) [361]65.7 (57.0‐73.5) [636]40‐75>.99LYM1.4 (1.0‐1.8) [361]1.5 (1.1‐2.0) [638]1.1‐3.2.37LYM%23.7 (16.5‐30.4) [361]23.8 (15.7‐31.6) [636]20‐50>.99MON0.5 (0.4‐0.7) [361]0.50 (0.4‐0.7) [636]0.1‐0.6>.99PLT211 (155‐259) [361]211.5 (167‐267.3) [636]125‐350>.99NLR (%)2.8 (1.9‐4.4) [361]2.8 (1.8‐4.7) [636]0.5‐5.7>.99LMR (%)2.8 (1.9‐4.0) [361]3.0 (1.9‐4.3) [636]1.8‐32>.99hsCRP (mg/L)2.7 (0.5‐27.2) [305]2.4 (0.4‐16.8) [571]0‐5>.99LDH (U/L)207 (170‐262.5) [284]201.5 (166‐249.8) [521]120‐250.08PCT (ng/mL)0.1 (0.0‐0.7) [61]0.2 (0.1‐0.8) [125]<0.1>.99Virological indicatorsPrevious infection3 (0.8)3 (0.5).47Hospitalized this timeNucleic acid positive7 (1.9)6 (0.9).18IgM positive3 (0.8)4 (0.6).70IgG positive8 (2.2)17 (2.6).67Re‐positive1 (0.3)0 (0.0).18Confirmed infection b 0 (0.0)1 (0.2).45Asymptomatic infection16 (4.4)22 (3.4).42Asymptomatic to confirmed infected1 (0.3)1 (0.2).68Close contacts c 5 (1.4)4 (0.6).22Confirmed infection in close contacts0 (0.0)0 (0.0)– Note. Data are presented as median (IQR) [No.] or absolute numbers and percentages (%), where No. is the total number of patients with available data. Multiple t‐test and χ 2 test were used for comparative analysis by SPSS24.0 software.Abbreviations: CT, computed tomography; hsCRP, hypersensitive C‐reactive protein; IQR, interquartile range; LDH, lactate dehydrogenase; LMR, lymphocyte‐to‐monocyte ratio; LYM, lymphocyte; MON, monocyte; NEU, neutrophil; NLR, neutrophil‐to‐lymphocyte ratio; PCT, procalcitonin; PLT, platelet; WBC, white blood cell.aLength of stay begins with admission to the buffer ward time and ends with transfer to an inpatient ward time, transfer to a designated hospital time, discharge time, or time at death. It does not include time in the outpatient or emergency department.bConfirmed cases were diagnosed according to the Guidelines for the Diagnosis and Treatment of COVID‐19 by the National Health Commission (trial version 7).cClose contacts were determined according to the close contacts management protocol of Diagnosis and Treatment Plan for COVID‐19 (trial version 6). * P < .05 was considered statistically significant.John Wiley & Sons, Ltd.As expected, most patients were transferred to inpatient wards after 3 days o