Novel subcutaneous low-molecular-weight heparin injection technique to reduce post-injection bruising

Objective: To investigate the efficacy of a novel low-molecular-weight heparin injection technique compared to the standard technique relative to bruising incidence, bruise size, and pain. Methods: A randomized controlled trial was conducted in 44 patients with acute deep vein thrombosis. Patients who were randomized into the control group received a 10-s duration injection with immediate needle withdrawal, whereas study group patients received a 30-s duration injection with a 10-s pause before needle withdrawal. Two injection sites were assessed for pain and bruising between 48 and 60 h after injection. Results: Bruises occurred in 50.0% and 18.2% of control and study group patients, respectively (p = 0.03). Mean bruise size between 48 and 60 h after injection was 172.73 ± 372.60 mm² and 28.18 ± 70.01 mm² in the control group and study group, respectively (p = 0.026). Pain scores were comparable between groups. Conclusion: A 30-s duration injection with a 10-s pause before needle withdrawal resulted in significantly fewer and smaller bruises.