To Describe the clinical characteristics of severe and critical COVID-19.~To analyze the relationship between the clinical characteristics and their clinical prognosis;~To analyze the relationship between clinical intervention and their clinical prognosis.
This study is to clarify the clinical characteristics of severe and critical COVID-19 from March 1st ,2022 to June 9th, 2022 in Shanghai and to explore the relationship between the characteristics and prognosis in these patients.