Effect on pain of changing the needle prior to administering medicine intramuscularly: a randomized controlled trial

Aim. This paper is the report of a study to determine whether changing the needle before administering an intramuscular injection could reduce pain, and to investigate gender differences in pain perception. Background. A skilled injection technique can make the patient's experience less painful and avoid unnecessary complications, and the use of separate needles to draw up and administer medication ensures that the tip of the needle is sharp and free from medication residue. Method. A randomized controlled trial was carried out between January 2009 and May 2009 with 100 patients receiving diclofenac sodium intramuscularly in an emergency and traffic hospital in Izmir, Turkey. The primary outcome was pain intensity measured on a numerical rating scale. Each patient received two injections by the same investigator using two different techniques. The two techniques were randomly allocated and the patients were blinded to the injection technique being administered. After each injection, another investigator who had no prior knowledge of which injection technique was used immediately assessed pain intensity using a numerical rating scale. Descriptive statistics, paired t-test and t-test were used to evaluate the data. Results. Findings demonstrated that changing the needle prior to intramuscular medication administration significantly reduced pain intensity. A statistical difference in pain intensity was observed between the two injection techniques. Conclusion. The results supported the hypothesis that changing the needle prior to administering the medicine significantly reduced pain intensity.