Does Lidocaine Mixture for Preventing The Pain on Propofol Injection Affect Anesthetic Induction and Hemodynamic Responses to Tracheal Intubation

Han, Tae Hyun; Lee, Hye Won; Cho, Hun; Lim, Hae Ja; Chang, Seong Ho; Yoon, Suk Min

Abstract

Background: We hypothesized that intravenous lidocaine mixed with propofol may have an influence on anesthesia induction and hemodynamic responses to propofol induction and endotracheal intubation as well as propofol-induced pain on injection.
Methods
Seventy-five patients were allocated to group L1 (2% lidocaine 1.5 mg/kg, n=25), group L2 (2% lidocaine 2 mg/kg, n=25) or group C (normal saline 0.05 mL/kg, n=25) according to the lidocaine dosage mixed with propofol 2 mg/kg. The pain on injection was scored as none, mild, moderate, and severe. The site of pain and recall of pain were also recorded. Loss of verbal response was observed during induction. Mean arterial blood pressure (MAP) and heart rate (HR) were recorded before anesthetic induction (baseline value), immediately before and after endotracheal intubation, and every min until 5 min thereafter.
Results
Ninety-two percent of patients reported pain upon injection in group C, whereas 8% of the patients in group L1 and no patient in group L2. Loss of verbal response before injection of total dose of propofol was observed in 44% in group L2, 36% in group L1 and 28% in group C. Lowered MAP caused by propofol increased significantly after endotracheal intubation in all three groups (p<0.05). HR increased immediately and 1 min after endotracheal intubation in all three groups (p<0.05).
Conclusions
Our results indicate that intravenous lidocaine 1.5 mg/kg or 2 mg/kg mixed with propofol 2 mg/kg significantly reduces the incidence and the degree of pain, but does not affect anesthesia induction and hemodynamic responses to propofol and tracheal intubation.