Role of D-Dimer in Covid-19 pneumonia: sensitive marker of inflammation, predictor of mechanical ventilation, thromboembolic events and early marker of post covid-lung fibrosis; Prospective Multicentric, Observational, Interventional study in tertiary care setting in India

Abstract

Introduction: Covid-19 pneumonia is heterogeneous disease with variable effect on lung parenchyma, airways and vasculature leading to long term effects on lung functions. Materials and methods: Multicentric, prospective, observational and interventional study included 1000 covid-19 cases confirmed with RT PCR. All cases were assessed with HRCT thorax, oxygen saturation, inflammatory marker as D-Dimer at entry point and follow up. Age, gender, Comorbidity and use BIPAP/NIV and outcome as with or without lung fibrosis were key observations. In selected cases, lower limb venous doppler and CT pulmonary angiography to rule out DVT or PTE. Statistical analysis is done by using Chi square test. Observations and analysis: Age (<50 and >50 years) and gender (male versus female) has significant association with D-Dimer level. [p<0.00001] & [p<0.010] respectively. CT severity score at entry point with D-Dimer level has significant correlation. [p<0.00001] D-Dimer level has significant association with duration of illness prior to hospitalization. [p<0.00001] Comorbidities have significant association with D-Dimer level. [p<0.00001] D-Dimer level has significant association with oxygen saturation. [p<0.00001] BIPAP/NIV requirement has significant association with D-Dimer level. [p<0.00001] Timing of BIPAP/NIV requirement during hospitalization has significant association with DDimer level. [p<0.00001] Follow-up D-Dimer titer during hospitalization as compared normal & abnormal to entry point level has significant association with post-covid lung fibrosis, deep vein thrombosis and pulmonary thromboembolism. [p<0.00001]. Conclusion: D-Dimer has documented very crucial role in covid-19 pneumonia in predicting severity of illness and assessing response to treatment during hospitalization and follow up titers have significant role in step-up or step-down interventions in critical care setting.