Background: High incidence of site-pain associated with subcutaneous heparin therapy has been reported. In spite of the use of different methods to decrease pain after subcutaneous heparin injection, the effect of duration of injection on its subsequent pain has not been studied enough. Therefore, this study was carried out to compare the duration of 10 and 30 seconds subcutaneous heparin injections.

Materials and Methods : This semi-experimental study was conducted on 80 patients treating with subcutaneous heparin in medical-surgical wards of Babol Shahid Beheshti Hospital. Heparin was injected randomly to either right or left hand with a 12 hour interval during 10 seconds as control and 30 seconds as study technique. After each injection, patients reported the site-pain (from zero-ten) by VAS (Visual Analogue Scale) instrument, immediately and in sitting position. Data(Patient's pain score in 10 and 30 Seconds injection per gender, age group and type of disease) were analyzed using SPSS Version 15 and Wilcox on, Mann-Whitney and Kruskal -Wallis tests.

Results: Severity of pain in control group was 2.10 ± 1.40 and in study group 1.65 ± 1.39 . The difference was significant (P<0.0 1 ). In comparison of the two techniques with demographic characteristics, in 10 second injection, the obtained pain from control group was significantly more than case group among female patients, those in medical wards and patients in 40-60 years range (P<0.0 0 , P<0.0 3, P<0.0 0 respectively) .

Conclusion: This Study results indicated that increasing the duration of subcutaneous heparin injection could significantly decrease the patient's pain. To reduce the subsequent physical and psychological stresses of patients and increase the patient's trust to health care providers and nurses, injection of heparin in 30-seconds is recommended.