Comparison of EMLA and lidocaine with or without sodium bicarbonate in prevention of spinal needle insertion pain

Abstract

Objective: To compare the effects of different agents in preventing pain during spinal needle insertion. Method: After institutional approval and informed patient consent, eighty patients (American Society of Anesthesiologist physical status I-II, aged 20-60 years) were included in the study. Patients were randomly allocated to four groups. Sixty minutes before operation, a 2.5 gr 5% EMLA cream patch was applied in group I and a placebo patch cream to the other groups. The EMLA and placebo patches were applied over the L2-3 or L3-4 interspace area. Upon arrival in the operation room, the patches were removed. Subcutaneous tissue was infiltrated with 2 mL 1 % lidocaine in group II, 2 mL 1 % lidocaine with 0.1 mL (8.4 %) sodium bicarbonate (1 mEq mL-1) in group III, and 2 mL saline solution in groups I and IV. Puncture pain during introducer insertion was assessed by the patient and by a blind observer to the group allocation using a 10-cm visual analog scale (VAS). Results: There were no significant dif ferences in pain scores between the lidocaine and EMLA groups. The lidocaine with sodium bicarbonate group was assessed as having the least painful needle insertion. Conclusion: We concluded that addition of sodium bicarbonate to local anesthetic significantly reduced spinal meedle insertion pain. Administration of lidocaine or EMLA provided equal analgesia.