Shahla Najafidolatabad, Jammohamad Malekzadeh, Zinat Mohebbinovbandegani
Objective. To compare the pain severity caused by the application of the Z-track and Air-Iock intramuscular injections. Methodology. Unblinded clinical trial , where 90 female subjects aged between 18 and 60 years old were randomly assigned to two groups; the first group received the tramadol intramuscular injection using the Z-track technique (ZT) and the second group received it through the air-lock method (AL). A 10 centimetre linear visual scale was used to evaluate the injection pain. The scale length was considered as the pain severity. Data were analyzed using the SPSS version 13. Groups' age, Body Mass index (BMI), and pain intensity were compared using unpaired student's t test. Results. The study showed that the pain severity of patients in the AL method group was lower than in the ZT technique group (p<0.05). There was no significant statistical difference between the age, the number of injections previously applied and the BMI between the groups. Conclusion. AL method produced less pain than the ZT technique; therefore it can be considered a better choice for intramuscular injections.