Author(s)

Shigeaki Masuda¹, Sakiko Sakamaki², Yuko Yasuhara³, Yueren Zhao⁴, Kensaku Takase⁵, Yoshihiro Kai⁶, Tetsuya Tanioka^3*, Rozzano C. Locsin³

¹Department of Nursing, Nara Medical University, Nara, Japan.
²The Tokushima University Hospital, Tokushima, Japan.
³Department of Nursing Outcome Management, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan.
⁴Department of Psychiatry, Fujita Health University School of Medicine, Aichi, Japan.
⁵Department of Neurosurgery, Tokushima Central Prefectural Hospital, Tokushima, Japan.
⁶Department of Mechanical Engineering, Tokai University, Kanagawa, Japan.

Intramuscular injections can cause damage to arteries, veins and nerves. Achieving maximum effects of medications through precise intramuscular (IM) injections must be assured and with certainty, particularly with long-acting injection drugs (LAI). The purpose of this study is to determine precision in IM LAIs of patients with schizophrenia. These evidences estimate “Distance from the Epidermis to the Under-Fascia” (DEUF) and “Distance from Epidermis to the Upper-Arm Bone” (DEB) of the deltoid muscle. Explanatory variables include body height, weight, body-mass index (BMI), deltoid-muscle circumference, fat percentage and muscle mass measured by body composition monitor. Sixty nine subjects are included based on the Diagnostic Statistical Manual of Mental Disorders (DSM-IV, 1994), and receive treatments of typical and atypical antipsychotic LAI. There are 46 males and 23 females with average age of 51.41 (Standard Deviation = 13.58) and ranging from 21 to 81 years who are all right-handed. Ultrasonographic data and those from explanatory variables are calculated using Spearman’s rank correlation coefficients. Multiple regression analysis (step-wise method/forced input method) is performed assuming DEUF or DEB as dependent variables. Significant correlations are found with highest adjusted R-square. Paired t-tests show differences in average values of actual ultrasonographic measurements assigned to DEUF or DEB, and the regression equations for accuracy. Ultrasonographic values are assigned multiple-regression equations as true values, and the calculated values are compared with those obtained by regression equations. There are no significant differences observed for either the right or left arm. The multiple regression equations for BMI and fat percentages (upper extremity estimation) of DEUF, and for BMI and injection site circumference of estimated DEB, successfully value the DEUF and DEB. By using these multiple regression equations for IM injection to the deltoid-muscle, DEUF can better ensure accurate LAI into the muscle through body monitor, DEB, and measured values of the deltoid-muscle injection site circumference.

Estimating Equation, Long Acting Injectable, Deltoid Muscle, Schizophrenia

Masuda, S. , Sakamaki, S. , Yasuhara, Y. , Zhao, Y. , Takase, K. , Kai, Y. , Tanioka, T. and Locsin, R. (2016) Explanatory Variables as Evidence for Precision in Intramuscular Long-Acting Injections of Patients with Schizophrenia. Open Journal of Psychiatry, 6, 125-134. doi: 10.4236/ojpsych.2016.61015.