Description
BACKGROUND: Self-administered epinephrine is the primary out-of-hospital treatment of anaphylaxis. Intramuscular injection of epinephrine results in higher peak plasma concentration than subcutaneous injection. With the prevalence of obesity, autoinjectors may not have an adequate needle length for intramuscular injection. OBJECTIVES: To measure muscle depth and evaluate predictors of autoinjector needle length inadequacy. METHODS: We performed a prospective cross-sectional study of a convenience sample of low acuity emergency department patients aged 18 to 55 years. We recorded demographic data, measured thigh circumference, and calculated body mass index (BMI). Using ultrasound, we took depth-to-muscle measurements of the vastus lateralus in a standing position, with and without gentle pressure to simulate muscle compression that occurs with correct autoinjector use. We conducted univariate analyses using chi(2) and t tests with P
Subject
*Needles; Adolescence; Adolescent; Adult; Anaphylaxis – Drug Therapy; Anaphylaxis/*drug therapy; Body Mass Index; Cross Sectional Studies; Cross-Sectional Studies; Epinephrine – Administration and Dosage; Epinephrine/*administration & dosage; Equipment Design; Equipment Failure; Female; Human; Humans; Injections; Intramuscular – Equipment and Supplies; Intramuscular/instrumentation; Male; Middle Age; Middle Aged; Needles; Prospective Studies; Quadriceps Muscle/*anatomy & histology/diagnostic imaging; Quadriceps Muscles – Anatomy and Histology; Quadriceps Muscles – Ultrasonography; Sex Factors; Sympathomimetics – Administration and Dosage; Sympathomimetics/*administration & dosage; Ultrasonography; Young Adult