Appropriate Needle Lengths Determined Using Ultrasonic Echograms for Intramuscular Injections in Japanese Infants

Abstract

Adjuvanted vaccines are recommended for administration through an intramuscular route. The Centers for Disease Control and Prevention (CDC) has recommended the anterolateral thigh using a 22 - 25-G 25-mm (1 inch) needle for infants, injected at a 90˚ into the skin surface, and using a 16 mm (5/8 inch) for newborns. Appropriate needle lengths may differ depending on racial backgrounds. In the present study, the thickness of the epidermis and lengths from the skin surface to the muscle fascia and bone were measured using ultrasonic echograms in order to determine suitable needle lengths for Japanese infants aged 2, 3, 4, 5, 6, and 12 - 15 months old. The thickness of the epidermis was 1.44 - 1.54 mm (95% CI), and the lengths from the skin surface to the muscle fascia and bone were 11.52 - 12.28 mm (95% CI), and 25.66 - 26.93 mm (95% CI), respectively, at the anterolateral thigh.