Ketorolac versus meperidine: ED treatment of severe musculoskeletal low back pain

The study objective was to assess the efficacy and patient acceptance of ketorolac as an alternative to meperidine for the treatment of severe musculoskeletal low back pain (LBP). A double blinded prospective trial in a convenience sample of patients >18 years of age presenting to an urban university hospital emergency department (ED) was conducted over a 19-month period. Patients were included if the pain was musculoskeletal in origin and was severe enough to warrant parenteral analgesics. Patients were randomized to receive 1 mg/kg meperidine intramuscularly (IM) or 60 mg ketorolac IM. Pain intensity was measured preadministration and at 60 minutes via a 100 mm Visual Analog Scale (VAS). Outcomes measured at 60 minutes were pain intensity decrease (PID), patient satisfaction, rescue analgesia requirement, sedation level, and adverse effects. Clinically significant pain reduction was defined as a PID of at least 13 mm or a reduction in pain of least 30%. One hundred fifty-five patients were enrolled (meperidine = 75, ketorolac = 80) and 153 patients completed the study. At 60 minutes the mean PID was 7 mm less in the ketorolac group (95% confidence interval [CI] - 15 mm to 2.6 mm). Pain reduction of at least 30% occurred in 63% of the ketorolac group versus 67% of the meperidine group (95% CI, odds ratio [OR] .43 to 1.61). Rescue analgesia was required in 35% of the ketorolac group versus 37% of the meperidine group (95% CI, OR .47 to 1.74). Patient satisfaction was less in the ketorolac group (ketorolac 68% satisfied versus meperidine 74% satisfied) however this was not significant (95% CI, OR .66 to 2.72). Sedation level and adverse effects were significantly greater in the meperidine group. Ketorolac shows comparable single dose analgesic efficacy to a single moderate dose of meperidine with less sedation and adverse effects in an ED population with severe musculoskeletal LBP. The trend for greater pain reduction and patient satisfaction with meperidine needs further investigation.