No abstract

An intramuscular injection (IMI) is an injection given directly into the central area of a specific muscle. Certain medicines need to be administered by the gluteal route for these to be effective. The aim of this study was to determine the influence of body mass index (BMI), subcutaneous fat, and muscular thickness of the dorsogluteal IMI site among healthy Japanese women. There were 39 healthy female subjects who volunteered and met the criteria. Their ages ranged from 40s to 60s (50.82 ± 6.04). With the data collected using the B-mode ultrasound images of the dorsogluteal site, it was found that the distance from the epidermis to the under-fascia (DEUF) of the gluteus maximus was dissimilar between the subject's right and left buttocks. It was found that the distance from the epidermis to the iliac bone (DEI) was significantly more on the right than on the left buttocks. In the case of an adult Japanese woman with a BMI of 21 or more, the DEUF of the gluteus medius was found to be about 30 mm, and the DEI was approximately 50 mm or more. Based on these findings, it is recommended that a needle length of 38 mm (1.5 inches) can be safely used to administer IMIs to the gluteus medius muscle to effectively and efficiently deliver medications through the IMI route.

Long Acting Injectable (LAI) medications for patients with schizophrenia is commonly administered to relieve their symptoms. Through shared decision-making and clinical evidence-based, psychiatrists should systematically offer LAIs to all patients requiring long-term antipsychotic treatment as a first-line treatment. Gluteal intramuscular (IM) injection requires accurate insertion of needles into the specific muscle area, often the outer upper quadrant of the buttocks, in order to achieve the required blood concentration. The purposes of this study were to compare the "Distance from the Epidermis to the Under-Fascia (DEUF)" and "Distance from the Epidermis to the Iliac Bone (DEB)" of the buttocks IM injection sites at the dorsogluteal and ventrogluteal sites among healthy Japanese volunteer subjects, and to identify the optimal insertion injection needle length. The DEUF and DEB at the gluteal regions were measured by ultrasonography. Welch's one-way analysis of variance was used to compare the DEUF and the DEB at the gluteal IM injection regions. There was no statistically significant difference observed between the right and left mean values of DEUF for Hochstetter and Clark's point at the ventrogluteal sites, and the Four and Three-way split or Double Cross point at the dorsogluteal sites. However in the DEB, the Hochstetter's point (P < 0.01) at ventrogluteal site on the right side, and Clark's point (P < 0.05) were significantly shorter than the Double Cross point at dorsogluteal sites (F = 4.38). The left buttocks S. Masuda et al. 204 Hochstetter's point was significantly shorter than the Double Cross point (F = 4.38, P < 0.01). These results, however, did not establish a statistically significant difference in the DEUF among injection sites. It was considered that the difference in the DEB depended on muscle volume and thickness in the gluteal injection sites.

This study was conducted with six patients with schizophrenia, four of whom received the atypical antipsychotic risperidone long-acting injectable (RLAI), and two patients receiving the typical depot injection (TDI). The purpose of this study was to determine the location (gluteus medius or maximus; deltoid muscles) and diffusion of typical and atypical antipsychotic medications administered intramuscularly using ultrasonography. When using the standardized depth of needle insertion, in some cases, the drug was injected into the gluteus maximus instead of the gluteus medius. Similarly, in some cases the TDI was not visible in the ultrasonographic images until sixteen days after the injection. This verifies how hard the injection site becomes when microspheres of RLAI is injected as compared to other muscle areas. These results confirmed that the gluteus muscle structure was the ideal muscle for depot injection as evidenced by the injection solution being dispersed and rendered not visible immediately after intramuscular injection (IM). With the use of ultrasonography, injection sites and drug dispersions were evaluated under a direct visual guidance, suggesting that ultrasonography is a useful method for establishing evidence for determining correct insertion of IM injection, diffusion of medications, and the effective administration of IM injections.

The aim of this study was to consider the characteristics of intramuscular diffusion status of risperidone and aripiprazole long acting injectable (LAI) by ultrasonography. Subjects were 40 adult subjects diagnosed with schizophrenia and treated with LAI [32 patients were risperidone LAI (RLAI) and 8 patients were aripiprazole LAI (ALAI)]. However, in this paper, only three cases (one RLAI case and 2 ALAI cases) were selected to illustrate the diffusion effects of both LAI. Dorsogluteal intramuscular (IM) injection sites were measured at prone position using the "double cross" method. Before LAI injection, the distance from the epidermis to the under-fascia (DEUF), and distance from the epidermis to the iliac bone (DEI) at the IM injection site were assessed by using ultrasonography: 1) the injection needle was inserted to the gluteus medius, and 2) observed the diffusion status within the muscle injected RLAI and ALAI were confirmed using the B-mode ultrasonography. Both RLAI and ALAI were depicted as high echogenicity with acoustic shadowing. It was considered that the diffusion states of LAIs by ultrasonography were important time course evaluations providing objective evidence.