Skin to Intramuscular Compartment Thigh Measurement by Ultrasound in Pediatric Population

Abstract

IntroductionPediatric obesity threatens the efficacy of medications given intramuscularly. In anaphylactic patients, epinephrine auto-injector needle lengths are potentially too short to reach the muscle compartment in patients with elevated body habitus. The objective of the study was to determine needle-length requirements for intramuscular injections in pediatric patients.MethodsWe used ultrasound to measure the distance from skin to muscle compartment of the thigh in 200 pediatric patients of various weight and body mass index who presented to the emergency department.ResultsPatients with higher body mass index had an increased distance to muscle and bone. If current recommendations were followed, 5% of patients within the EpiPen adult weight category and 11% of patients within the Centers for Disease Control and Prevention weight category would have potentially used a needle inadequate in length for intramuscular injections.ConclusionWith the increase in childhood obesity, needle lengths may be too short to effectively deliver medications to the intramuscular compartment. Needle length should be evaluated to accommodate pediatric patients with increased skin to muscle distance.

Pharmacokinetic and pharmacodynamic evidence of adrenaline administered via auto‐injector for anaphylactic reactions: A review of literature

“…Apart from needle length, the other risk factors for adrenaline being administered SC, and not IM, were an increased BMI 6,25,26,28,29,32–34 and female sex for adults (independent of BMI) 6,29,33 . Johnstone et al 29 reported in their study that 87% of females were at risk of SC injection compared to 0% of males.…”

“…26,27 However, in another paediatric study where a slightly longer needle was used as the reference (25.4 mm), again with no pressure being applied during USS, the risk of periosteal/IO injection was as high as 12% in those aged 2-5 years. 32 Apart from needle length, the other risk factors for adrenaline being administered SC, and not IM, were an increased BMI 6,25,26,28,29,[32][33][34] and female sex for adults (independent of BMI). 6,29,33 Johnstone et al 29 reported in their study that 87% of females were at risk of SC injection compared to 0% of males.…”

The Evaluation of Palpable Thigh Nodularity in Vaccination-age Children – Differentiating Vaccination Granulomas from Other Causes

“…It has previously been shown that the distance from the skin to the muscle compartment may be extremely variable in pediatric patients and that standard needle lengths may be too short to effectively deliver medications to the intramuscular compartment. [ 9 ] Granulomas are a local formation of specific cells including macrophages and lymphocytes, revealing a chronic inflammatory reaction against an inciting agent. [ 10 ] The etiology of vaccination granulomas has been described as an inflammatory response incited by the injection of a vaccine, particularly those which are aluminum adsorbed.…”

Epinephrine auto-injector needle length

“…Recently, Duong et al presented data on BMI versus skin to muscle distance and skin to bone distance without considering the age dependant successive increase of BMI [12]. BMI-limits in childhood and adolescence must include evaluation using age dependent and puberty stage dependant limits for BMI using z-scores.…”