The Effect of Lidocaine Patch for Postoperative Pain

The Efficacy and Safety of 5% Lidocaine Patch for Postoperative Pain in Unilateral Inguinal Herniorrhaphy

The lidocaine patch is currently only permitted for post herpetic neuralgia but the investigators want to study its effectiveness in post operative pain after inguinal herniorrhaphy

After open unilateral inguinal herniorrhaphy, patients are randomly divided into group L and group P groups. Group L attaches two lidocaine patches for 12 hours, above and below the incision site. Group P attaches two placebo patches for 12 hours, above and below the incision site. Pain scores are recorded for 30 minutes, 2 hours, 24 hours, and 1 week after surgery.

Inclusion Criteria:

• American Society of Anesthesiologists physical status I - II
• Scheduled open unilateral herniorrhaphy

Exclusion Criteria:

• body mass index (BMI) < 18.5 or ≥ 35 kg/m2
• severe renal or hepatic dysfunction
• allergy to amide-based local anesthetic agents
• taking class 1 antiarrhythmic drugs (tocainide and mexiletine, etc.)