Inhaled nebulised unfractionated heparin for the treatment of hospitalised patients with COVID‐19: A multicentre case series of 98 patients

Aims To determine the safety and efficacy‐potential of inhaled nebulised unfractionated heparin (UFH) in the treatment of hospitalised patients with COVID‐19. Methods Retrospective, uncontrolled multicentre single‐arm case series of hospitalised patients with laboratory‐confirmed COVID‐19, treated with inhaled nebulised UFH (5000 IU q8h, 10 000 IU q4h, or 25 000 IU q6h) for 6 ± 3 (mean ± standard deviation) days. Outcomes were activated partial thromboplastin time (APTT) before treatment (baseline) and highest‐level during treatment (peak), and adverse events including bleeding. Exploratory efficacy outcomes were oxygenation, assessed by ratio of oxygen saturation to fraction of inspired oxygen (FiO2) and FiO2, and the World Health Organisation modified ordinal clinical scale. Results There were 98 patients included. In patients on stable prophylactic or therapeutic systemic anticoagulant therapy but not receiving therapeutic UFH infusion, APTT levels increased from baseline of 34 ± 10 seconds to a peak of 38 ± 11 seconds (P