Adrenaline Auto-injector injuries to digits; a systematic review and recommendations for emergency management

Accidental injury to digits with Adrenaline Auto-injectors (AAIs) is becoming increasingly common. Digital AAI injury causes painful ischaemia that can lead to necrosis and patient anxiety. There is a lack of understanding amongst surgeons regarding how to manage these injuries. We aimed to determine an optimal treatment algorithm for their management.

We conducted a systematic review using the search engines MEDLINE, PubMed, EMBASE, CINAHL, BNI, AMED, Google Scholar. Search items included ("epinephrine OR adrenaline") AND ("Digit" OR "Finger" OR "Thumb") AND ("Injury" OR "Accidental").

A total of 49 articles were identified describing 111 cases. In 58 cases; 52% of cases were managed with phentolamine, 24% were managed with nitroglycerine and 7% were treated with warm soaks. The remaining 17% of cases were managed with a variety of alternative treatments. Mean recovery time following treatment with phentolamine infiltration was 33 min, whilst symptoms persisted for several hours in some cases with observation/warm soaks and nitroglycerine. Phentolamine was more effective when injected into the AAI puncture site (mean resolution time: 17 min) in comparison to injection as a digital block (74 min).

Phentolamine is the most effective method of reversing symptoms and treating ischaemic digits when compared to alternative therapies. Symptoms resolved much quicker when phentolamine was infiltrated into the site of injury compared to being infiltrated as a digital block. We propose a treatment algorithm for management of these injuries. Hand surgeons should be aware of AAI injuries and be able to advise on their management.