title: Subcutaneous emphysema following trans-cricothyroid membrane injection of local anesthetic.
abstract: OBJECTIVE
  To present a case of preoperative subcutaneous emphysema (SCE) as a complication of trans-cricothyroid membrane (TCM) injection of lidocaine for awake intubation.
  
  
  METHODS
  A 48-yr-old man with cervical myelopathy was scheduled for elective cervical discectomy. Airway topical anesthesia consisted of lidocaine pledgets and TCM injection. After successful awake fibreoptic intubation was performed, SCE was noted in the neck region. The main differential diagnosis of preoperative SCE included air leak via the anterior needle track from TCM injection or disruption of mucosal membrane in the aerodigestive tract. The latter was excluded by panendoscopy and an upper GI swallow study. The most likely explanation for SCE was air leak from the anterior needle tract. The subcutaneous emphysema resolved spontaneously without sequella.
  
  
  CONCLUSIONS
  Subcutaneous emphysema is a rare but potentially serious complication of TCM injection of lidocaine. Anesthesiologists should be familiar with the differential diagnosis, investigations and management of SCE.
authors.affiliation: Department of Anesthesia, Toronto Western Hospital, University of Toronto, Ontario, Canada. dwong@torhosp.toronto.on.ca
authors.forename: D T
authors.initials: DT
authors.lastname: Wong
authors.forename: G P
authors.initials: GP
authors.lastname: McGuire
mesh_terms: D000779:Anesthetics, Local / Q000008:administration & dosage*; D001999:Bronchoscopy; D003413:Cricoid Cartilage; D003937:Diagnosis, Differential; D006801:Humans; D007267:Injections / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D013352:Subcutaneous Emphysema / Q000175:diagnosis / Q000209:etiology* / Q000628:therapy; D013957:Thyroid Cartilage
chemical_list: D000779:Anesthetics, Local