Hooked epinephrine auto-injector devices in children: four case reports with three different proposed mechanisms

Abstract

Background: The prevalence of epinephrine auto-injectors (EAI) use is on the rise. Our objective was to describes children with hooked EAI needles that were embedded in soft tissues. Case presentation: Results: Two children self-injected in their shins. The embedded EAIs required removal in the Emergency Department. Both needles were hooked and splayed at the tip. A boy in anaphylaxis kicked his leg during EAI injection and the hooked needle embedded under his skin and was difficult to dislodge. The exposed needle was curved. A girl had an EAI administered for anaphylaxis, which was also difficult to dislodge. On removal, the distal needle tip was hooked approximately 160 degrees. Images of the device revealed that the needle fired off-center from the device and the device components were cracked. We propose three different explanations for these hooked EAI needles. The first is that the needle could hit bone during injection and curve rather than penetrates further. Secondly, the needle could bend when the patient moves during injection. Thirdly, if a needle fires sufficiently offcenter to hit the cartridge carrier, this could hook the needle prior to injection. Conclusions: Awareness of the reasons for needle hooking, damage observed, and challenges and successful approaches to their removal, can better prepare the provider for these uncommon events. Teaching parents, children and educators about safe EAI storage and appropriate restraint during use may prevent some of these accidental injuries. Reporting device failures may lead to improvements in device performance and design.

Unintentional Epinephrine Auto-Injector Maxillofacial Injury in a Pediatric Patient

“…Postulations from similar case studies regarding the curvature of auto-injector needles include bending when hitting a bone during injection, bending when the patient moves during injection, or if the needle fires off center and hits the cartridge carrier, hooking the needle prior to injection. 5 This situation should be anticipated and investigated with imaging by the treating physician before attempting to remove the needle blindly. Stabilizing the auto-injector with a pillow and bulky dressing will also prevent further bending of the needle, which would make removal more difficult.…”

Reversal of Digital Ischemia with Phentolamine After Accidental Epinephrine Injection

“…Therefore, the effects of epinephrine might be longer than its half-life [ 8 ]. Globally, the accidental injection rate of epinephrine has risen because of the increased use of autoinjectors, and has been found to occur once for every 50,000 EpiPen ® units sold [ 9 ]. The EpiPen® trainer was self-injected by about 16% of doctors who read the EpiPen ® device instructions and injected it into their thumbs [ 7 ].…”