Combination of subcutaneous and inhaled heparin: A study on lung oxygenation and ventilation in patients with severe COVID-19 on mechanical ventilation

Objective: To analyze lung oxygenation and ventilation effects with combined subcutaneous and inhaled heparin for severe coronavirus disease 2019 (COVID-19) on mechanical ventilation. Design: A pilot observational retrospective cohort study using secondary data from medical records in August 2020-April 2021. Setting: Patients with severe COVID-19 on mechanical ventilation in the primary Intensive Care Unit (ICU). Patients and participants: Consecutive sampling was used to recruit 20 participants with severe COVID-19 on mechanical ventilation according to inclusion and exclusion criteria. Patients were divided into two groups: one received subcutaneous systemic heparin (HS) 5,000 IU every 12 hours. The other (combined heparin [HC]) received subcutaneous heparin 5,000 IU every 12 hours and inhaled heparin 25,000 IU. every 6 hours. Measurements and main results: Blood gas analyses conducted on days 0 to 5 measured lung oxygenation and ventilation, analyzed using analysis of variance (ANOVA) same-subject design, and one-way ANOVA evaluated differences on observation days. Improvements in lung oxygenation and ventilation were observed in both groups. The HS group showed at least one pair of observation days with different results, while the HC group had no differences on any day, meaning lung oxygenation improved with only subcutaneous heparin. Lung ventilation in HS and HC groups showed at least one pair of different days, meaning lung ventilation improved in both groups. Conclusion: Subcutaneous heparin is sufficient for improving lung ventilation and oxygenation in severe COVID-19 mechanical ventilation.