Methods
This is a retrospective cohort study of 59 patients with confirmed
COVID-19 pneumonia hospitalized at Infection Division of Union Hospital,
Huazhong University of Science and Technology in Wuhan, China from
January 25 to February 15, 2020. All patients were diagnosed with
COVID-19 pneumonia according to World Health Organization interim
guidance7. A retrospective review of the
characteristics of these patients during the whole hospital period was
performed through the electronic medical record system of our hospital,
the last was monitored up to March 15, 2020. The ethics committee of
Union Hospital (Wuhan, China) approved this study.
The clinical classification of COVID-19 reference the Diagnosis and
Treatment Plan of COVID-19 suggested by National Health Commission of
China8 (the seventh edition). The ordinary COVID-19
was defined to with fever, respiratory or other symptoms, but pneumonia
asterisk in imaging procedure. The severe COVID-19 was defined as
meeting any one of following items: Respiratory rate≥30 breaths /min;
Arterial oxygen saturation≤93% at rest; PaO2/FiO2≤300 mmHg. All
patients were treated with supportive care whatever they may needed
respectively, including administration of oxygen (nasal cannula,
noninvasive mechanical ventilation, invasive mechanical ventilation
(IMV), or IMV with extra corporeal membrane oxygenation), antibiotic,
antiviral and anticoagulant therapy, immunomodulator or
methylprednisolone and so on. All of patients who were treated
anticoagulant therapy in this study were precautionary, Low Molecular
Weight Heparin (LMWH) (40-60mg enoxaparin/day) for 6 days at least or
longer. Patients underwent blood routine blood test, coagulation, and
biochemical tests and chest x-rays or computed tomography many times.
For example, D-Dimer monitoring per 2-4d until it became stable and
normal. It should be noted that all the clinical data used in this study
were collected from the first day of hospital admission except D-Dimer
that from the diverse stages of the diseases many times.
The evaluation of outcomes consisted of the time of CT imaging
improvement was observed first time, hospital-stay time and the clinical
improvement during 7 days and 14 days, defined as the change in oxygen
support reference the seven-category ordinal scale9.
The seven-category ordinal scale consisted of the following categories:
1, not hospitalized with resumption of normal activities; 2, not
hospitalized, but unable to resume normal activities; 3, hospitalized,
not requiring supplemental oxygen; 4, hospitalized, requiring
supplemental oxygen; 5, hospitalized, requiring nasal high flow oxygen
therapy, noninvasive mechanical ventilation, or both; 6, hospitalized,
requiring ECMO, invasive mechanical ventilation, or both; and 7, death.
Normally and abnormally distributed quantitative variables were compared
using the Student’s t-test and the Mann–Whitney U test, respectively.
Categorical variables were compared using the chi-squared test. The
results were given as the mean± standard deviation, median
(interquartile range), or number (percentage), wherever appropriate. The
level of the D-Dimer was reviewed by bivariate logistic regression
analysis for their ability to predict states of illness. Survival curves
were developed using the Kaplan-Meier method with log-rank test. A P
value<0.05 was considered statistically significant. All analyses were
performed with SPSS 25.0 for windows.