On February 3rd, 2020, the conversion of Wuchang Fangcang Shelter Hospital from Wuchang Hongshan Stadium was started, and it was completed in only 29 hours. It was directly transformed from a stadium hall and was divided into three areas: A, B, and C. Each area was divided into a different number of subareas could accommodate 10-30 closely packed beds[1]. The large-scale use of the Fangcang Shelter Hospital is iconic in the history of Chinese medical rescue. Only the mild to moderate COVID-19 patients were admitted to the Fangcang Shelter Hospital. For the more serious patients, they would be temporarily transferred to the designated hospital for further treatment after a short period of stay in Fangcang Shelter Hospital. According to the WHO report, by 11 April 2020, a total of 1,610,909 patients with COVID-19 have been confirmed in 177 countries, and the number is still increasing[14]. According to relevant experience in China, the establishment of Fangcang Shelter Hospitals can effectively control the source of infection, cut off the transmission route, protect those susceptible people, reduce the overload of medical staff in regular hospitals, and more rationally use limited medical resources for the treatment of severe and critical illnesses patient. At the same time, the patients in the Fangcang Shelter Hospital received daily monitoring similar to those in regular hospitals during hospitalization, which helped to detect those patients who were aggravated and need timely medical treatment and respiratory support treatment. Thus could reduce the number of patients who died without timely treatment.
CT imaging results are very important for the determining whether a patient with COVID-19 can be discharged[15], so it is necessary to gather medical staff that can make an accurate and rapid diagnosis from CT imaging. Due to the emergency construction of the Fangcang Shelter Hospital and the temporary deployment of medical staff, the medical equipment is limited. In particular, CT equipment is expensive, and the construction of machine rooms, including transportation and loading, requires considerable manpower, material resources and time. On February 21, 2020, the construction of a relocatable CT cabin was completed, which provided powerful technical support for the diagnosis of COVID-19. This effort represents one of the fastest construction projects in China.
According to the basic patient information (Table 1), the median age was 53 years; the majority of the patients were 40-70 years old, and all patients had a course of disease longer than 13 days. This may be related to the gradual recovery from COVID-19 after 14 days [11]. The interval between the two CT scans was different for each patient, which may be related to the conditions of the Fangcang Shelter Hospital, such as the large number of patients and the limited number of doctors and medical equipment.
As shown in Table 1, 66 (79.5%) patients showed improvement and 2 (2.4%) patients showed recovery according to the CT imaging changes. The imaging features of these patients indicated that the lesions were significantly better pre-discharge compared to those of the previous CT, thus meeting the discharge criteria (Figure 4 and Figure 5). There were 12 patients that showed no changes in the CT images (Figure 3). Of these, 10 patients had normal previous and pre-discharge CT images, and the other 2 patients only showed a few GGOs and fibrosis: both patients met the discharge criteria. The course of disease in both of these patients was longer than 35 days, indicating that as the course of disease progressed, the lesions were absorbed more completely. According to the results of the analysis, the CT imaging changes are mainly reflected in the changes in the presentation of consolidation and fibrosis. Although there are always ground glass opacities on the CT images, they were essentially thinner on the pre-discharge CT images.
There were also 3 patients that showed progression, and the interval between the two CT scans was more than 14 days, which may be related to the evolution of the disease course[16]. Figure 2 shows CT images from a 64-year-old woman diagnosed with COVID-19. On January 28, 2020, the CT images showed no obvious abnormalities in the bilateral lungs. Because of the need for the prevention and control of infectious diseases, we did not take the pre-admission CT film out of the Fangcang Shelter Hospital to the doctor's office and reading room in the clean area. Therefore, we use the special mobile phone of the Fangcang Shelter Hospital to take the patient's CT film and then use the WeChat app to send it to the mobile phone and computer outside the Fangcang Shelter Hospital. Although the image quality is not good, it also satisfies the comparison between the new and old films. This is a creative solution for our radiology department to deal with this COVID-19 epidemic while working in the Fangcang Shelter Hospital, and it is worthy of reference and reference for Fangcang Shelter Hospitals in other countries. On February 25, chest CT showed new small flake GGO in the posterior basal segment of the right lower lobe with linear opacities at the edges, indicating that absorption improvement had occurred over this period. In this patient, the interval between the two CT scans was 27 days; we have not detected imaging signs of deterioration or later improvement of absorption that may have occurred in this period. As with the other 80 patients, we conducted a complete follow-up after the three progression patients were discharged from the Fangcang Shelter Hospital. The final results showed that the conditions in all three patients had further improved, and none of them were hospitalized again for treatment.
The study has some limitations. First, some of the CT films of the COVID-19 patients had been obtained prior to admission to the Fangcang Shelter Hospital. Since the previous CT films had been contaminated by 2019-nCoV themselves, the original CT film could not be obtained for comparison. Instead, simple photos were taken by mobile phone in the Fangcang Shelter Hospital and sent to the reading area outside the hospital for comparison. Second, due to the conditions in the Fangcang Shelter Hospital, the interval between the two CT scans was different for each patient, with some patients having much larger intervals than others. This was mainly because the clinical symptoms or nucleic acid tests of these patients did not meet the discharge criteria, and the pre-discharge CT scan was not started until the criteria were met. Finally, the medical staff was only temporarily deployed, with a team of three doctors of different specialties reviewing CT films and deciding whether the patient could be discharged. The advantages and disadvantages of this kind of medical staff formation need to be further explored.
In short, due to the shortage of medical staff, the lack of medical resources, and the difficulty in obtaining CT equipment within a short time, COVID-19 patients meeting discharge criteria should be released from Fangcang Shelter Hospitals as soon as possible. Regardless of whether the CT image of the patient shows no change, improvement, recovery or even progression of the disease, as long as the patient is within the absorption improvement period and meets the other discharge criteria, he or she can be discharged.