title: Reduction of pain on injection of propofol: combination of nitroglycerin and lidocaine.
abstract: OBJECTIVE
  Pain on propofol injection is a common adverse effect. This study examined the effect of a combination of nitroglycerin and lidocaine on pain during propofol injection compared to lidocaine alone.
  
  
  METHODS
  In a double-blind, prospective trial, 90 patients scheduled to undergo elective plastic surgery were allocated randomly to three groups, to receive lidocaine 20 mg (n = 30), a combination of lidocaine 20 mg and nitroglycerin 0.1 μg/kg (n = 30), or normal saline as a placebo (n = 30), with venous occlusion for 1 min, followed by the administration of 25 % of the total calculated dose of propofol (2 mg/kg) into a dorsal hand vein. The pain intensity during the propofol injection was assessed using a four-point scale (0 = none, 1 = mild, 2 = moderate, 3 = severe). Hemodynamic variables-mean arterial pressure and heart rate-were measured during the preoperative and intraoperative periods.
  
  
  RESULTS
  A significantly higher proportion of patients in the placebo group (83 %) experienced pain compared to the lidocaine and combination groups (43 and 7 %, respectively; both, P < 0.01). The incidence of pain in the combination group was lower than that in the lidocaine group (P < 0.01). The pain score (median) was lower in the lidocaine (0) and combination (0) groups than in the placebo group (2); (P < 0.01). The hemodynamic variables were similar in the three groups.
  
  
  CONCLUSIONS
  A combination of nitroglycerin 0.1 μg/kg and lidocaine 20 mg with venous occlusion for 1 min was more effective than lidocaine 20 mg alone in decreasing pain during propofol injection.
authors.affiliation: Department of Anesthesiology and Pain Medicine, School of Dentistry, Kyungpook National University, 130 Dongdukro, Jung-gu, Daegu, 700-721, Republic of Korea. jeon68@knu.ac.kr
authors.forename: Younghoon
authors.initials: Y
authors.lastname: Jeon
mesh_terms: D000328:Adult; D018686:Anesthetics, Intravenous / Q000008:administration & dosage / Q000009:adverse effects*; D004311:Double-Blind Method; D017558:Elective Surgical Procedures; D005260:Female; D006801:Humans; D008012:Lidocaine / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D005996:Nitroglycerin / Q000008:administration & dosage*; D010146:Pain / Q000188:drug therapy* / Q000517:prevention & control*; D010147:Pain Measurement / Q000379:methods; D015742:Propofol / Q000008:administration & dosage / Q000009:adverse effects*; D011446:Prospective Studies; D019651:Plastic Surgery Procedures; D013518:Surgery, Plastic; D055815:Young Adult
chemical_list: D018686:Anesthetics, Intravenous; D008012:Lidocaine; D005996:Nitroglycerin; D015742:Propofol