Lidocaine Plus Morphine Versus Lidocaine Plus Paracetamol for Bier Block: A Double-Blind Randomized Controlled Trial

Abstract

Purpose: Intravenous regional anesthesia (Bier block) is widely used as an anesthetic technique for operations of short duration of the distal upper or lower extremities. We compared the efficacy of intravenous regional anesthesia with lidocaine plus paracetamol versus lidocaine plus systemic morphine for short-duration hand and forearm surgeries.

Design: A double-blind randomized controlled trial with two parallel arms: lidocaine plus morphine (control) and lidocaine plus paracetamol were carried out at a University hospital.

Methods: We included men and women aged 20 to 70 years scheduled for short surgical procedures (30-60 minutes) distal to the elbow. Intravenous regional anesthesia was carried out by injecting 45 cc lidocaine 0.5% plus 300 mg paracetamol for the paracetamol group; or 45 cc lidocaine 0.5% plus 4 mg intravenous morphine for the control group. The primary outcome was postoperative pain-free period in minutes since deflation of proximal tourniquet. The secondary outcome was the highest intensity of postoperative pain on the visual analog scale within 2 hours after deflating the proximal tourniquet.

Findings: There was no significant difference between morphine and paracetamol in the duration of postoperative pain-free period (P = .078) and the mean intensity for maximum pain (P = .106). However, severe pain was significantly more frequent in the morphine group (P = .001). Paracetamol seemed to be safer than morphine as an adjuvant to lidocaine.

Conclusions: We recommend using 2 cc paracetamol (300 mg Apotel) as the adjuvant to lidocaine for intravenous regional anesthesia.

Keywords: Bier block; intravenous regional anesthesia; lidocaine; morphine; paracetamol.