The Effect of Duration of Subcutaneous Injection on the Extent of Bruising and Pain Intensity at Injection Sites among Patients Receiving Enoxaparin Sodium: A Randomized Self-Controlled Clinical Trial

Enoxaparin sodium, in most subcutaneous injections, causes local reactions, such as bruising and pain, at the injection sites. On the other hand, one of the important roles of nurses is safe injection.. This study aimed at determining the effect of duration of subcutaneous injection of enoxaparin sodium on the extent of bruising and pain intensity at the patients’ injection sites in 2013..Patients and In this randomized, self-controlled, clinical trial, 100 patients admitted in two educational hospitals affiliated to Bushehr University of Medical Sciences who were treated with enoxaparin were selected using convenience sampling. For each patient, two subcutaneous injection methods were performed: 10-second subcutaneous injection on the right side of the abdomen as the control group and 30-second subcutaneous injection on the left side of the abdomen as the intervention group. The first injection site was determined using simple random assignment. The bruising area was determined by using computer software 48 and 72 hours after each injection. Also, pain intensity was measured by Numeric Rating Scale (NRS) immediately after each injection. The data were then entered into the SPSS statistical software (v. 21) and were analyzed using non-parametric tests. Statistical significance was set at P < 0.05.. The mean and standard error of bruising in 10- and 30-second injections after 48 h were 45.53 ± 6.35 and 23.69 ± 3.27 mm2, respectively. After 72 h, these measures were obtained as 26.45 ± 4.70 and 14.76 ± 3.52 mm2, respectively (P < 0.001). Besides, the median and interquartile range of pain intensity scores in 10- and 30-second injections were 5 (4 - 7) and 3 (1.25 - 5), respectively, (P < 0.001).. The results indicated that increasing the length of enoxaparin subcutaneous injection reduced the extent of bruising and pain intensity at the injection sites..