Effects of cold application before subcutaneous injection of low-molecular-weight heparin on pain, bruising, and hematoma formation: A randomized controlled trial

Aims: With daily subcutaneous low-molecular-weight heparin (LMWH) injections for long periods, there is a high risk of local side effects, such as pain, bruising, and hematoma.This study aimed to compare the impact of cold application on post-injection pain, bruising, and hematoma in patients receiving subcutaneous LMWH following urologic surgery. Methods:This was a single-blind, randomized control trial.Urology inpatients were randomly assigned to three groups; Group 1: cold application for 2 min before injection, Group 2: cold application for 5 min before injection, and Group 3: control group with no cold application.Post-injection pain was assessed immediately after injection.Bruising and hematoma were assessed at 48 th and 72 nd hours. Results:The study included 26 patients in Group 1 (age=63.85±9.89years; male=84.6%),26 patients in Group 2 (age=64.54±11.66years; male=80.8%),and 26 patients in Group 3 (age=65.65±11.36years; male=88.5%).The pain scores in Groups 1 (11.58±12.06)and Group 2 (6.08±9.11)were lower than Group 3 (28.35±20.97)(p<0.001).At the 48 th hour, the frequency of bruising in Group 1 (11.5%) and Group 2 (11.5%) was lower than that in Group 3 (38.5%)(p=0.021), and the bruise size in Group 1 (4.00±1.73mm) was lower than that in Group 3 (15.00±7.07mm) (p=0.020).No hematomas was detected in any patient groups at the 48 th and 72 nd hours. Conclusions:This study showed that although cold application for 2 or 5 minutes before injection reduced pain and bruising frequency, application for 2 minutes was more effective on bruise size.