Role of Nebulised Heparin as an Adjunct in Critically-ill COVID-19 Patients: A Randomised Controlled Trial

Introduction: Coronavirus Disease 2019 (COVID-19) is associated with an increased risk of Venous Thromboembolism (VTE) and coagulopathy. The available studies have shown the anticoagulant and mucolytic effects of nebulised heparin in non COVID-19 patients. Hence it was decided to conducted to study the efficacy of nebulised heparin in patients suffering from COVID-19 pneumonia requiring mechanical ventilation.Aim: To evaluate the safety and efficacy of nebulised heparin administered to patients with COVID-19.Materials and Methods: A double-blinded randomised controlled trial was conducted at Basaveshwara Medical College and Hospital in Chitradurga, Karnataka, India among 100 patients with COVID-19 who required mechanical ventilation from February 2021 to May 2021. They were randomly assigned to two equal groups of 50 patients each. One group received nebulised heparin, and the other group received a placebo. The patients were compared for baseline characteristics, coagulation characteristics, and Oxygen Saturation (SpO(2)). Data were analysed using Statistical Package for Social Sciences (SPSS) version 22.0, expressed as frequency and percentages, and displayed in tables and figures. The association between two variables was determined using the Chi-square test and paired t-test.Results: The two groups did not differ significantly in terms of age, sex, respiratory failure, vasopressin use, and severity score. Respiratory failure was present in 54% of the heparin group and 38% of the placebo group. Vasopressin was used in 64% of the heparin group and 56% of the placebo group. The severity score was 4.44 in the heparin group and 4.42 in the placebo group. Activated Partial Thromboplastin Time (APTT) levels did not differ significantly between the groups. None of these parameters showed significant differences between the heparin and placebo groups. However, both groups showed a significant difference in Thrombin Antithrombin (TAT) complex levels from baseline to follow-up (p<0.05). D-Dimer levels decreased during follow-up, and Spo2 improved significantly in the nebulised heparin group compared to the placebo group.Conclusion: Nebulised heparin used as an adjunct in critically ill COVID-19 patients was shown to decrease TAT and D-Dimer levels. Nebulised heparin also significantly improved oxygenation levels. Importantly, heparin nebulisation was not associated with any adverse events, even when administered with systemic heparin.