title: Lidocaine/tetracaine patch (Rapydan) for topical anaesthesia before arterial access: a double-blind, randomized trial.
abstract: BACKGROUND
  Arterial catheterization is painful and is associated with patient stress and anxiety. Analgesia is usually provided by subcutaneous injection of local anaesthetic. An alternative is topical anaesthesia, such as Rapydan which is a novel topical anaesthetic patch containing 70 mg each of lidocaine and tetracaine. We therefore tested the hypothesis that Rapydan patch analgesia is non-inferior to subcutaneous local anaesthetic.
  
  
  METHODS
  Ninety patients undergoing elective major cardiac surgery were included in this prospective, double-blind clinical trial. Patients were randomly assigned to receive either a lidocaine/tetracaine patch, followed by subcutaneous injection 0.5 ml of normal saline solution, or placebo patch with subsequent subcutaneous injection of 0.5 ml of lidocaine 1%. Pain during arterial catheterization using 100-mm-long visual analogue scale (VAS) was the primary outcome. Other outcomes were pain during anaesthetic/saline injection and plasma tetracaine concentrations.
  
  
  RESULTS
  VAS pain scores during arterial puncture were comparable in both groups and Rapydan was non-inferior to subcutaneous lidocaine. Pain scores at the time of subcutaneous injection were significantly lower (better) in patients assigned to the lidocaine/tetracaine patch than to lidocaine (P=0.001). Plasma tetracaine concentrations never exceeded the detection limit of 25 ng ml(-1) at any time in any patient.
  
  
  CONCLUSIONS
  Both the lidocaine/tetracaine patch and subcutaneous injection of lidocaine provided comparable pain control during arterial catheter insertion. Subcutaneous lidocaine caused discomfort during injection, whereas the lidocaine/tetracaine patch required placement 20 min before the procedure. Given adequate time, the patch provided better overall analgesia by obviating the need for subcutaneous infiltration.
authors: Department of Cardiothoracic and Vascular Anaesthesia and Intensive Care Medicine, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria.
authors: K
authors: K
authors: Ruetzler
authors: B
authors: B
authors: Sima
authors: L
authors: L
authors: Mayer
authors: A
authors: A
authors: Golescu
authors: D
authors: D
authors: Dunkler
authors: W
authors: W
authors: Jaeger
authors: M
authors: M
authors: Hoeferl
authors: J
authors: J
authors: You
authors: D I
authors: DI
authors: Sessler
authors: G
authors: G
authors: Grubhofer
authors: D
authors: D
authors: Hutschala
mesh_terms: D000279:Administration, Cutaneous; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000772:Anesthesia, Local / Q000379:methods; D000779:Anesthetics, Local / Q000008:administration & dosage*; D002405:Catheterization, Central Venous / Q000009:adverse effects*; D004311:Double-Blind Method; D004338:Drug Combinations; D005260:Female; D006801:Humans; D008012:Lidocaine / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000209:etiology / Q000517:prevention & control*; D011446:Prospective Studies; D013748:Tetracaine / Q000008:administration & dosage*; D057968:Transdermal Patch; D055815:Young Adult
chemical_list: D000779:Anesthetics, Local; D004338:Drug Combinations; D013748:Tetracaine; D008012:Lidocaine