Comparison of Two Techniques of IV Lidocaine on Propofol Injection Pain
Condition: Injections, Intravenous
Study type: Interventional
Phase: Phase 4

Summary: 
      Intravenous lidocaine is commonly given through an intravenous (IV) line prior to injection
      of propofol to reduce the amount of pain during propofol injection. The investigators want to
      study if giving the lidocaine through the IV while the forearm on the same limb has a
      tourniquet applied to it to prevent "washing out" of the lidocaine prior to propofol
      injection helps reduce propofol injection pain.
    

Detailed description: 
      The investigators expect that tourniquet lidocaine is superior to straight non-tourniquet
      lidocaine in reducing propofol injection pain. The investigators also wanted to determine the
      association of tourniquet duration on reduction of pain with propofol administration. Small
      studies indicate that 60 seconds of tourniquet lidocaine is superior to 30 seconds or less of
      tourniquet duration or mixed lidocaine/propofol for injection. The investigators suspect many
      clinicians do not use the 60-second tourniquet technique due to the extra time involved but
      hypothesize that a more practical application by applying the tourniquet as soon as the
      patient is positioned on the operating table will not only be more widely adopted by
      clinicians as it does not cause delay but also provide the necessary amount of time for
      benefit from the tourniquet. The investigators also wanted to record the time from tourniquet
      application to start of propofol administration, which the investigators predict would be at
      least 60 seconds to see if there is a correlation between duration of venous stasis of IV
      lidocaine and pain benefit.

      Methods and Measures

      Design This was conducted as a randomized controlled trial of two methods of administering
      lidocaine prior to propofol injection.

      Setting The study setting was located within North Carolina Baptist Health, an academic
      medical center, in the Endoscopy Suite or Outpatient Surgery Center where subjects were
      scheduled to receive propofol as part of their sedation or anesthetic.

      Sample Size The investigators estimated that 25 subjects in each of the two groups was
      required to test the hypothesis based on prior studies.

      Interventions and Interactions

      The investigators used two groups:

        -  Group 1: 50mg of 2% lidocaine given just prior to the propofol dose through the IV line.

        -  Group 2: 50mg of 2% lidocaine given IV with venous occlusion applied when the patient is
           positioned on the operating room table and timed until the onset of propofol
           administration. The tourniquet the investigators used was a Quick Release tourniquet
           applied to the forearm 10cm distal to the elbow joint in the tourniquet group. Venous
           stasis was confirmed with cessation of flow from hanging IV fluid.

      For both groups, no premedication was given, which is the normal practice for these
      procedures. Study procedures involved placing a 20 gauge intravenous (IV) catheter in a vein
      distal to the mid forearm. Venous occlusion was achieved by either a latex free tourniquet or
      McKesson Quick Release tourniquet applied to the forearm 10cm distal to the elbow joint.
      Tourniquet pressure was somewhat variable but sufficient to cause venous stasis as confirmed
      by no flow of hanging IV fluid. Injections were delivered at roughly 1 ml/sec.

      Schedule of events in the study (all performed by 1 of the 2 investigators:

        -  Day of procedure: holding area

             -  Consent subject for study participation

             -  Randomly assign patient to one of two groups

        -  Day of procedure: procedure area

           -Accompany subject to the operating or procedure room, perform protocol from the group
           to which the subjects were assigned, while noting outcome measures such as
           self-described discomfort and observer graded discomfort

        -  Day of procedure: recovery area

           -Revisit subject in recovery 30 minutes after their procedure to determine
           post-procedure recall of discomfort

        -  Post-study period

        -  Analyze data

      Analytical Plan The investigators will analyze results initially using descriptive
      statistics. Comparison between groups was done using chi square tests for proportions, and
      t-tests or ANOVA procedures for continuous variables. Regression analysis was performed to
      identify independent outcome predictors. Other inferential statistical analysis was conducted
      as appropriate.

      Informed Consent One of the two investigators obtained signed informed consent from each
      subject. This was performed in the holding room prior to the procedure since most subjects
      had their pre-procedure examination performed in the holding room and were not seen prior to
      the day of their procedure.
    

Intervention name(s): Lidocaine injection flushed; Lidocaine injection tourniquet
Intervention type(s): Drug; Drug
Intervention description(s): The investigator administers IV lidocaine and flushes it into the subject prior to administering propofol.; Intravenous lidocaine: tourniquet
Other intervention name(s): Xylocaine; Xylocaine; Tourniquet
Intervention MeSH terms: Lidocaine
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: A randomized, controlled trial of two methods of administering lidocaine prior to propofol injection
Masking: Single (Participant)
Primary purpose: Treatment
Keywords: Propofol; lidocaine; pain