Treatment of Acute Orofacial Pain with Lower Cervical Intramuscular Bupivacaine Injections: A 1-Year Retrospective Review of 114 Patients

Aims: To describe 1 year's experience in treating orofacial pain with intramuscular injections of 0.5% bupivacaine bilateral to the spinous processes of the lower cervical vertebrae. Methods: A retrospective review of 2,517 emergency department patients with discharge diagnoses of a variety of orofacial pain conditions and 771 patients who were coded as having had an anesthetic injection between June 30, 2003 and July 1, 2004 was performed. The records of all adult patients who had undergone paraspinous intramuscular injection with bupivacaine for the treatment of an orofacial pain condition were extracted from these 2 databases and included in this retrospective review. Pain relief was reported in 2 different ways: (1) patients (n = 114) were placed in 1 of 4 orofacial pain relief categories based on common clinical experience and face validity and (2) pain relief was calculated based on patients' (n = 71) ratings of their pain on a numerical descriptor scale before and after treatment. Results: Lower cervical paraspinous intramuscular injections with bupivacaine were performed in 118 adult patients. Four charts were excluded from review because of missing or inadequate documentation. Pain relief (complete or clinical) occurred in 75 patients (66%), and partial orofacial pain relief in 32 patients (28%). No significant relief was reported in 7 patients (6%). Overall, some therapeutic response was reported in 107 of 114 patients (94%). Orofacial pain relief was rapid, with many patients reporting complete relief within 5 to 15 minutes. Conclusion: This is the first report of a large case series of emergency department patients whose orofacial pain conditions were treated with intramuscular injections of bupivacaine in the paraspinous muscles of the lower neck. The findings suggest that lower cervical paraspinous intramuscular injections with bupivacaine may prove to be a new therapeutic option for acute orofacial pain in the emergency department setting. Keywords: allodynia, bupivacaine, cervical, headache, injection, intramuscular, orofacial, pain, paraspinous, trigeminocervical