The effect of injection duration and injection site on pain and bruising of subcutaneous injection of heparin

AIMS AND OBJECTIVES: To determine and compare the effects of four methods of subcutaneous heparin injection on pain and bruising in abdomen and thighs. BACKGROUND: Subcutaneous heparin injection is a common nursing clinical intervention. Nurses frequently inject heparin subcutaneously and this action often results in some complications such as bruising, haematoma, pain and induration in the injection site. There are also some other factors inducing complications associated with heparin injection, including the injection site and the injection duration. DESIGN: A quasi-experimental within-subject design. METHODS: This study was conducted on 90 patients with COPD hospitalised in two ICU wards at two teaching hospitals in urban areas of Iran. They were administered heparin subcutaneously, 4000 units every 12 hours. Each patient received four injections in their abdomen and thighs, using four different methods. The number and size of bruising at the injection site were measured through a flexible millimetre ruler, 48 hours after each injection. The severity of pain was measured through pain visual analogue scale immediately after each injection. Collected data were analysed by descriptive and analytical statistics using spss 11.5 software. RESULTS: In the method 15 seconds injection duration and waiting for 5 seconds before withdrawing the needle, the number of bruising was significantly lower and size of bruising was significantly smaller, but no significant difference was found in the severity of pain. However, in other methods, the severity of pain in thighs was significantly higher than in abdomen, but no statistically significant difference was reported between the size and number of bruising in abdomen and thighs. CONCLUSIONS: The method 15 seconds injection duration and waiting for 5 seconds before withdrawing the needle is recommended to be used for subcutaneous heparin injection by clinical nurses. As to the results, the severity of pain in abdomen was lower than in thighs. RELEVANCE TO CLINICAL PRACTICE: This study proposed a suitable method for subcutaneous heparin injection in order to reduce pain and bruising.