Clinical Features and Outcome Analysis of Patients Infected with Severe and Critical COVID-19 Associated Pneumonia

Abstract Background Until now, information on the clinical characteristics of severe and critical patients with COVID-19 is extremely limited.The aim of the present study was to analyse the clinical features of these patients and influencing factors of clinical outcome, and explore treatment effects of prone position on COVID-19 patients with severe ARDS. Methods A retrospective analysis was performed on 55 COVID-19 patients in the ICU of Zhongnan Hospital of Wuhan University from January 6 to February 15, 2020 in Wuhan, China. Case data from each patient were collected and related clinical outcomes on day 14 of ICU admission were recorded. The follow-up deadline was February 29, 2020. Results Of the 55 patients included, 35 were male (63.6%), with an average age of 63.0 (SD 15.2) years, and 80.0% were patients over 50 years old. The first three symptoms were fever (36 cases, 65.5%), fatigue (13 cases, 23.6%), and cough (11 cases, 20.0%). The rate of invasive mechanical ventilation was 52.7% (29 cases); on the 14th day of ICU admission, 31 patients(56.4%) were improved, and 19 (34.5%) were worsened. On the 14th day after entering the ICU, a comparative analysis showed that peripheral blood CD4, CD8, and NK cell counts in deteriorated patients were significantly lower than those in improved patients (P<0.05). Meanwhile, concentrations of IL-10, IL-4, IL-6 and TNF-α in deteriorated patients were higher than those in improved patients (P <0.05). Among a total of 27 prone position sessions, the oxygenation index (PaO2 / FiO2 ) of 9 prone position sessions(33.3%) improved, and the PaCO2 in arterial blood gas analysis of 5 sessions(18.5%) improved. Conclusion The majority of patients with severe and critical COVID-19 in the ICU were over 50 years old and male. 52.7% need invasive mechanical ventilation. On the 14th day of admission, 56.4% of the patients improved, 34.5% of the patients deteriorated. The rate of deaths during hospitalization was 21.8%. The worsening of COVID-19 patients might be related to excessive inflammatory and immune responses. In addition, prone ventilation may improve oxygenation in some COVID-19 patients with severe ARDS, but a significant mortality benefit with proning was uncertain.