Annotated Bibliography of correct site selection for intramuscular medical administration

Nakajima, Y., Mukai, K., Takaoka, K., Hirose, T., Morishita, K., Yamamoto, T., Yoshida, Y., Urai, T., et. al. (2017). Establishing a new appropriate intramuscular injection site in the deltoid muscle. Human vaccines & immunotherapeutics, 13(9), 2123-2129.

In this recent evidence-based study, a group of researchers from the Kanazawa University in Japan established a new intramuscular injection (IM) site in the deltoid or arm muscle, which they have found to be the safest and the most appropriate location for IM injections. Even in their earlier studies, they had researched and concluded in favour of the deltoid muscle as the site of choice for IM injections. This study reconfirmed their earlier findings, but with improvements. In this study, the authors selected 30 healthy volunteers and examined 4 original IM injection sites on the deltoid muscles. Thickness of the deltoid muscle was also measured through ultrasonography to arrive at the required depth and angle for needle insertion. The results of this study specifically revealed that the intersection between the anteroposterior axillary line and the perpendicular line from the mid-acromion of the deltoid muscle is best for IM injections because of its distance from the axillary nerve, posterior circumflex humeral artery and the subdeltoid brusa. Such a specific identification of IM injection site, with accompanying illustrations, serves as a very helpful guidance for clinicians who are frequently administering vaccines and other medicines in muscular tissues. However, the study had a significant limitation in that its research was based on only a small sample. Therefore, the research findings cannot be generalised and it might need further studies to assess its applicability on obese individuals with higher body mass index or on individuals from different age groups. Another limitation in this study is that it does not assure effectiveness of administering multiple injection doses in this particular site. It established the new site of IM injections for a single dose. Nevertheless, this study is a focused step towards the clinical practice of parenteral injections, whereby the specifically identified area of the deltoid muscle remains the site of choice for IM injections.