Results
A total of 38 severe patients who accept anticoagulant therapy were enrolled into the study from consecutive 59 confirmed cases. Except 16 ordinary patients were not treated with anticoagulant therapy, there were 4 serve patients complicated with atrial fibrillation and 1 with acute myocardial infraction were also excluded to the study even they were treated with anticoagulant therapy (Figure 1).
22 (57.9%) severe patients recovered with low-flow nasal cannula (LFNC) only. 16(42.1%) severe patients’ condition worsened, they need higher oxygen support therapy, of which eleven with high flow nasal cannula (HFNC) or noninvasive mechanical ventilation and five with invasive mechanical ventilation were consisted. Continuous D-Dimer monitoring showed a significant difference (P<0.001) between the stage of LFNC (2.01(1.37-2.89)mg/L) and HFNC (13.57(7.33-19.84)mg/L) (Table.1). Using binary logistic regression analysis evaluate the influence of D-Dimer level on degree of patient’s condition found that compared to those D-Dimer≤3mg/L, patients with higher D-Dimer increase the risk (OR=15.697, P<0.001) to develop to much more severe illness (Table.2).
The mean age at disease onset of the total (n=38) was 69.4±12.2 years, incidence time was 10.6±6.2 days, and 21 (55.3%) were male. 21 (55.3%) patients had one or more comorbidities, including hypertension, diabetes and heart disease. All patients were treated with preventative anticoagulant therapy, eighteen when D-Dimer≤3mg/L and twenty until D-Dimer>3mg/L. The parameters of clinical characteristics and laboratory tests between two parts were compared (Table.3).
According to the change in oxygen support reference the seven-category ordinal scale, 10 (55.6%) patients’ condition improvement in 7 days in the group of D-Dimer ≤3 when anticoagulant therapy was initiated, while 7 (35%) in the D-Dimer >3 (P=0.757). 17 (83%) patients’ condition improvement in 14 days in the D-Dimer≤3 compared with 10 (50%) in the D-Dimer>3 (P=0.043, Table.4). Then time to clinical improvement were examined, there was a difference in 14 days of improvement between D-Dimer≤3 and D-Dimer>3 (P=0.03), while no difference in 7 days (P=0.24, Figure.2).
The mean days at the time of CT imaging improvement was 12.1±3.6 days in the group of D-Dimer≤3, while 16.2±6.4 days in D-Dimer>3 (p=0.028). The hospital stays in the two groups were 27 (25.5-30.5) days and 28 (27-36.5) days separately, there was no statistically significant (p=0.086, Figure. 3).