2. Materials and Methods

This study is a randomized clinical trial with two intervention parallel groups and is single-blind. This is a comparative study of the technique and location of the subcutaneous injection of enoxaparin on the size of bruise and pain intensity at the injection site. The study was done in patients admitted to the cardiac care units of Zahedan City teaching hospitals in 2019. The participants were selected from patients admitted to the CCU (coronary care unit) and PCCU (progressive coronary care unit). The samples were selected by purposeful sampling method and according to the inclusion criteria, then they were randomly assigned to one of the two intervention groups. In the first group, enoxaparin was injected subcutaneously in the abdomen and arm according to the doctor’s prescription (40 or 60 mg) for 30 seconds. In this method, after the needle enters the subcutaneous space, enoxaparin was injected for 30 seconds and the needle was immediately pulled out of the tissue. In the second group, according to the doctor’s prescription (40 or 60 mg), enoxaparin was injected subcutaneously in the abdomen and arm by 15+ 5 seconds method. In this method, after the needle entered the subcutaneous space, enoxaparin was injected for 15 seconds and then, the needle was remained in the subcutaneous space for 5 seconds and then removed. Because of the small number of study variables, we used the formula for comparing means for two independent communities. Also, based on similar studies [33], taking into account the test power of 90%, reliability of 99%, and the probability of falling sample size of 20%, a total of 30 patients were selected for each group.