Comparison of intravenous lidocaine versus morphine in alleviating pain in patients with critical limb ischaemia.

Background: Numerous drugs have been proposed to alleviate ischaemic limb pain, but none have been successful in relieving ischaemic pain thoroughly and rapidly.
Objective: To compare the effectiveness of intravenous lidocaine and intravenous morphine in decreasing pain in patients with critical limb ischaemia.
Methods: A randomised double-blind controlled trial was performed in 63 patients with critical limb ischaemia recruited from the emergency department between October 2012 and December 2013; 23 patients were excluded and the remainder were randomly divided into two groups of 20 patients. Patients in the lidocaine group received lidocaine infusion (2 mg/kg) while patients in the morphine group received morphine (0.1 mg/kg). Patients' visual analogue pain scores (VAS), from 0 to 10, were reported before and 15 and 30 min after the infusion.
Results: Before the infusion the mean±SD VAS score was 7.50±1.93 in the lidocaine group and 7.65±1.92 in the morphine group. At 15 min the mean±SD VAS score in the lidocaine group was lower than in the morphine group (5.75±1.77 vs 7.00±1.83; mean difference 1.25, 95% CI 0.095 to 2.405) and, at 30 min, the mean±SD VAS score in the lidocaine group was again lower (4.25±1.48 vs 6.50±1.73; mean difference 2.25, 95% CI 1.218 to 3.282).
Conclusions: Lidocaine may be helpful in decreasing ischaemic pain in patients with critical limb ischaemia.
Trial Registration Number: http://www.irct.irIRCT201210148872N2.
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