Clinical trial NCT01494311: Rapydan Topical Anaesthesia for Arterial Cannulation
Official title: Lidocaine/Tetracaine Patch (Rapydan) for Topical Anaesthesia Before Arterial Access: A Double-blind, Randomized Trial
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE4
Conditions: Arterial Catheterization
Keywords: Arterial catheter
arterial cannula
Rapydan
lidocaine/tetracaine patch
topical anaesthesia
Lead sponsor: Medical University of Vienna
Sponsor class: OTHER
Collaborators: name: The Cleveland Clinic
name: Population Health Research Institute
First posted: 2011-12-16
Enrollment: 90
Sex: ALL
Minimum age (years): 18
Maximum age (years): 90
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: SUPPORTIVE_CARE

Brief summary: Arterial catheterization is painful and is associated with patient stress and anxiety. Analgesia is usually provided by subcutaneous injection of local anesthetic. An alternative is topical anaesthesia, such as Rapydan which is a novel topical anesthetic patch containing 70 mg each of lidocaine and tetracaine. We therefore tested the hypothesis that Rapydan patch analgesia is non-inferior to subcutaneous local anesthetic.

Detailed description: Many clinical procedures including arterial and venous punctures, percutaneous venous catheter insertion, lumbar puncture, and dermatological procedures are associated with pain and consequent patient discomfort.1-2 With the exception of venopuncture, arterial puncture is the most common invasive procedure performed on critically ill patients. Also, it is often necessary before induction of anaesthesia for invasive measurements of blood pressure and collection of arterial blood samples in patients undergoing major cardiac surgery. Injection of local anesthetics before insertion causes intra-dermal turgor and can trigger local vasoconstriction, both of which reduce puncture success rate.

An alternative approach is to use topical anesthesia for percutaneous procedures. However, intact skin presents a significant barrier to topical anesthetic preparations. Therefore, topical anesthetic preparations typically must be applied under occlusive dressings for 45-60 minutes before vascular access - which is often longer than is clinically practical.

Rapydan (also known as Synera in the United States) is a novel topical anesthetic patch that contains 70 mg each of lidocaine and tetracaine. The central area of each Rapydan patch consists of a Controlled Heat Assisted Drug Delivery pod which is designed to allow for application just 20 minutes before percutaneous procedures. However, the efficacy of Rapydan topical analgesia has yet to be quantified for the more intense pain resulting from arterial puncture. We thus compared routine analgesia (subcutaneous injection with 0.5 ml of 1% lidocaine) with heated lidocaine/tetracaine patches. Specifically, we tested the hypothesis that lidocaine/tetracaine patch analgesia is non-inferior to that provided by subcutaneous lidocaine injection for insertion of arterial catheters.

Ninty 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, looking identically to the Rapydan patch and subsequent subcutaneous injection of 0.5 ml of lidocaine 1%. Pain during arterial catheterization using 100-mm-long visual analog scale (VAS) was the primary outcome. Other outcomes were pain during anesthetic/saline injection and plasma tetracaine concentrations.

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 at any time in any patient.

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 minutes before the procedure. Given adequate time, the patch provided better overall analgesia by obviating the need for subcutaneous infiltration.

Eligibility criteria: Inclusion Criteria:

* Patients having elective valve-replacement or coronary artery bypass grafting requiring arterial access before induction of anaesthesia.

Exclusion Criteria:

* analgesic use within 24 hours before surgery
* injury or infection at the planned puncture site
* known allergy to local anesthetics
* drug abuse
* alcoholism or psychiatric disorders
* childbearing potential without adequate birth control
* abnormal Allen's test

Primary outcomes:
measure: Pain during arterial catheterization
timeFrame: During and minutes after arterial cannula insertion, day 1.
Secondary outcomes:
measure: Pain during annethetic/saline injection.
timeFrame: During and minutes after injection, day 1.
measure: Blood concentration of plasma tetracaine
timeFrame: Minutes before and after patch application, day 1.
measure: Patient Satisfaction
timeFrame: At conclusion of procedure, day 1.
measure: Investigator's evaluatuion of pain during catheter insertion
timeFrame: At conclusion of procedure, day 1.
measure: Difficulty of puncture
timeFrame: During catheter insertion, day 1.
measure: Number of punctrue attempts
timeFrame: During catheter insertion, day 1.
measure: Incidence of edema and erthema at the patch site
timeFrame: Evaluated immediately after patch removed, day 1.
Other outcomes:
Locations:
city: Cleveland
country: United States
facility: Cleveland Clinic Department of Outcomes Research
state: Ohio
city: Vienna
country: Austria
facility: Medical University of Vienna
city: Hamilton
country: Canada
facility: Population Health Research Institute, McMaster University
state: Ontario
Study officials:
References: