title: Safety of Epinephrine in Digital Nerve Blocks: A Literature Review.
abstract: BACKGROUND
  Digital nerve blocks are commonly performed in emergency departments. Health care practitioners are often taught to avoid performing blocks with epinephrine due to a risk of digital necrosis.
  
  
  OBJECTIVE
  To review the literature on the safety of epinephrine 1:100,000-200,000 (5-10 μg/mL) with local anesthetics in digital nerve blocks in healthy patients and in patients with risk for poor peripheral circulation.
  
  
  METHODS
  PubMed, Web of Science, and the Cochrane Library were searched in June 2014 using the query "digital block AND epinephrine OR digital block AND adrenaline". The searches were performed without any limits.
  
  
  RESULTS
  Sixty-three articles were identified, and 39 of these were found to be relevant. These include nine reviews, 12 randomized control trials, and 18 other articles. Most studies excluded patients with risk for poor peripheral circulation. Two studies described using epinephrine on patients with vascular comorbidities. No study reported digital necrosis or gangrene attributable to epinephrine, either in healthy patients or in patients with risk for poor peripheral circulation. In total, at least 2797 digital nerve blocks with epinephrine have been performed without any complications.
  
  
  CONCLUSIONS
  Epinephrine 1:100,000-200,000 (5-10 μg/mL) is safe to use in digital nerve blocks in healthy patients. Physiological studies show epinephrine-induced vasoconstriction to be transient. There are no reported cases of epinephrine-induced harm to patients with risk for poor peripheral circulation despite a theoretical risk of harmful epinephrine-induced vasoconstriction. A lack of reported complications suggests that the risk of epinephrine-induced vasoconstriction to digits may be overstated.
authors.affiliation: Department of Emergency Medicine, Karolinska University Hospital, Solna, Stockholm, Sweden.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Ilicki
mesh_terms: D000772:Anesthesia, Local / Q000379:methods*; D000779:Anesthetics, Local; D004837:Epinephrine / Q000008:administration & dosage / Q000009:adverse effects*; D005383:Finger Injuries / Q000628:therapy; D005385:Fingers / Q000473:pathology*; D005734:Gangrene / Q000139:chemically induced; D006801:Humans; D009336:Necrosis / Q000139:chemically induced; D009407:Nerve Block; D014034:Toes / Q000293:injuries / Q000473:pathology*; D014662:Vasoconstrictor Agents / Q000008:administration & dosage / Q000009:adverse effects*
chemical_list: D000779:Anesthetics, Local; D014662:Vasoconstrictor Agents; D004837:Epinephrine
keywords: adrenaline; analgesia; digital blocks; digital nerve blocks; digital trauma; epinephrine