Intravenous lidocaine for the emergency department treatment of acute radicular low back pain, a randomized controlled trial.
BACKGROUND
Acute radicular back pain is a frequent complaint of patients presenting to the Emergency Department.


OBJECTIVE
Determine the efficacy of intravenous lidocaine when compared to ketorolac for the treatment of acute radicular low back pain.


METHODS
Randomized double-blind study of 41 patients aged 18-55 years presenting with acute radicular low back pain. Patients were randomized to receive either 100 mg lidocaine or 30 mg ketorolac intravenously over 2 min. A 100-mm visual analog scale (VAS) was used to assess pain at Time 0 (baseline), and 20, 40, and 60 minutes. Changes in [median] VAS scores were compared over time (within groups) by the signed-rank test and between groups by the rank-sum test. A 5-point Pain Relief Scale (PRS) was administered at the conclusion of the study (60 min) and again at 1 week by telephone follow-up; [median] scores were compared between groups by rank-sum.


RESULTS
Forty-four patients were recruited; 41 completed the study (21 lidocaine, 20 ketorolac). Initial VAS scores were not significantly different between the lidocaine and ketorolac groups (83; 95% confidence interval [CI] 74-98 vs. 79; 95% CI 64-94; p = 0.278). Median VAS scores from baseline to 60 min significantly declined in both groups (lidocaine [8; 95% CI 0-23; p = 0.003]; ketorolac [14; 95% CI 0-28; p = 0.007]), with no significant difference in the degree of reduction between groups (p = 0.835). Rescue medication was required by 67% receiving lidocaine, compared to 50% receiving ketorolac. No significant change in PRS between groups was found at the conclusion or at the follow-up.


CONCLUSIONS
Intravenous lidocaine failed to clinically alleviate the pain associated with acute radicular low back pain.
Department of Emergency Medicine, Naval Medical Center San Diego, San Diego, California.
David A
DA
Tanen
University of Tokyo Medical School, Tokyo, Japan.
Mai
M
Shimada
Department of Emergency Medicine, Naval Medical Center San Diego, San Diego, California.
D Chris
DC
Danish
Department of Emergency Medicine, Naval Medical Center Portsmouth, Portsmouth, Virginia.
Frank
F
Dos Santos
Division of Emergency Medicine, University of Washington, Seattle, Washington.
Martin
M
Makela
Clinical Investigations Department, Naval Medical Center San Diego, San Diego, California.
Robert H
RH
Riffenburgh
D059787:Acute Pain / Q000188:drug therapy*; D061605:Administration, Intravenous; D000328:Adult; D000779:Anesthetics, Local / Q000008:administration & dosage*; D016861:Cyclooxygenase Inhibitors / Q000008:administration & dosage; D004311:Double-Blind Method; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D020910:Ketorolac / Q000008:administration & dosage; D008012:Lidocaine / Q000008:administration & dosage*; D017116:Low Back Pain / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D011843:Radiculopathy / Q000188:drug therapy
D000779:Anesthetics, Local; D016861:Cyclooxygenase Inhibitors; D008012:Lidocaine; D020910:Ketorolac
ketorolac; lidocaine; pain; radicular