Optimal Lidocaine Propofol Mixture for Painless Induction of Anesthesia

June 7, 2023 updated by: Fawzy Abbas Badawy, Sohag University

This research will be carried out in order to determine the optimal lidocaine dose in propofol lidocaine mixture to prevent pain on propofol injection during induction of general anesthesia using a modified Dixon's up-and-down method. Patients & methods: Include assessment of severity of pain on propofol injection using seven doses of lidocaine in lidocaine propofol mixture in ASA I&II patients aged 18-60 years with exclusion of patients with history of drug allergy, hepatic or renal impairment, cardiac problems, neurologic deficits or psychiatric disorders.

The primary outcome will be pain scale during injection and volume of propofol-lidocaine mixture used. Secondary outcome will be increase in heart rate and/or hand or forearm withdrawal during injection, patient satisfaction, demographic data, type and duration of surgery, Time for unconsciousness.

Aim of the work: To determine the Minimal effective dose of lidocaine in propofol lidocaine mixture to achieve painless induction of anesthesia using propofol.

Study Overview

Detailed Description

Rapid onset of action, smooth induction, favorable recovery and low rate of adverse effects have made propofol the most commonly used intravenous anesthetic for induction and maintenance of anesthesia. However, pain associated with propofol injection is still considered by many patients as the worst prioperative unpleasant experience.1 Therefore, a diversity of techniques have been suggested in the literature to solve this problem including pretreatment with local anesthetics, opiates, ketamine and alfentanil. 2-5 New propofol formulation was another way to alleviate this pain.6 Among these techniques lidocaine was investigated extensively whether as a pretreatment with the use of tourniquet, which is a time consuming technique, or mixed with propofol. Evaluation of optimal dose of lidocaine in propofol lidocaine mixture was widely assessed. However, evaluation of optimal lidocaine dose in propofol lidocaine mixture to prevent pain with newer formulations of propofol should be further evaluated. We hypothesize that optimal dose of lidocaine to alleviate pain with propofol injection might need further evaluation.

Patients and methods

This prospective randomized and double blinded study will be conducted in Sohag University Hospital after obtaining approval from Institutional Review Board and written informed consent from all patients before enrolment in this study. Patients scheduled for elective surgery under general anesthesia, aged 18 to 60 years and American Society of Anesthesiologists (ASA)physical status I & II will be selected for this study. Patients with history of drug allergy, hepatic or renal impairment, cardiac problems, neurologic deficits, psychiatric disorders or anxious patients who need sedation preoperatively will be excluded from the study.

Before entering the operating room premedication will not be allowed. In the operating room 20 gauge cannula will be inserted into a vein on the dorsum of the non-dominant hand & basic monitoring (pulse oximetry, electrocardiography, noninvasive blood pressure & end tidal carbon dioxide) will be applied to the patient before induction and throughout the procedure.

Mixtures of propofol, lidocaine and saline will be prepared by an anesthetist who is not involved in the study team according to the lidocaine dose sequence as shown in table (1) resulting into eight mixtures. The mixture will be injected at a rate of 20ml/minute using syringe pump until patient loose consciousness. The anesthetist who inject the propofol and the patient will be blinded to the lidocaine dose in the mixture.

Table 1 propofol lidocaine mixtures Mixture Propofol Lidocaine 2% (ml)(20mg/ml) Lidocaine concentration (%)

  1. 20ml 0.5
  2. 20ml 1 0.095
  3. 20ml 1.5 0.139
  4. 20ml 2 0.181
  5. 20ml 2.5 0.222
  6. 20ml 3 0.26
  7. 20ml 3.5 0.297
  8. 20ml 4 0.333

Pain scale will be explained to all patients preoperatively and they will be asked to report for pain sensation (no pain or mild, moderate or severe pain) The dose of lidocaine, in propofol lidocaine mixture, administered to each patient will be determined by the response of the previous patient using a modified Dixon's up-and-down method (using 10mg as a step size). The first patient will receive a mixture with 10mg lidocaine. If the patient report pain with propofol injection, then the next patient will receive a mixture with 10mg higher dose of lidocaine, if the patient report no pain with injection, then the next patient will receive a mixture with 10mg lower dose of lidocaine. The study will continue until we obtain seven crossover midpoints (No limited number).

The minimal effective dose of lidocaine that results in painless injection of propofol for 50% (ED50) of patients will be determined by calculating the midpoint dose of all independent pairs of patients after at least seven crossover points.

The following data will be recorded; Primary outcome: pain scale during injection and volume of propofol-lidocaine mixture used.

Secondary outcome: increase in heart rate and/or hand or forearm withdrawal during injection, patient satisfaction(will be assessed in the post anesthesia care unit (PACU) after regaining consciousness), demographic data, type and duration of surgery, Time for unconsciousness.

Aim of the work To determine the Minimal effective dose of lidocaine in propofol lidocaine mixture to achieve painless induction of anesthesia using propofol.

Study Type

Observational

Enrollment (Estimated)

100

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

  • Name: Fawzy A Badawy, MD

Study Locations

      • Sohag, Egypt
        • Recruiting
        • Sohag University Hospital
        • Contact:
          • Magdy M Amim, Professor

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

No

Sampling Method

Probability Sample

Study Population

Patients scheduled for elective surgery under general anesthesia, aged 18 to 60 years and American Society of Anesthesiologists physical status I & II will be selected for this study.

Description

Inclusion Criteria:

  • Patients scheduled for elective surgery under general anesthesia.
  • Aged 18 to 60 years
  • American Society of Anesthesiologists physical status I & II

Exclusion Criteria

  • History of drug allergy
  • Hepatic or renal impairment .Cardiac disease
  • Neurologic deficits ,psychiatric disorders
  • Anxious patients who need sedation preoperatively

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Pain scale
Time Frame: 9 months
Pain scale (mild, moderate or severe) during injection of propofol
9 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Heart rate
Time Frame: Before injection of propofol-lidocaine mixture and every minute for three minutes after start of injection
Heart rate
Before injection of propofol-lidocaine mixture and every minute for three minutes after start of injection
time for unconsciousness
Time Frame: 2 minutes after start of injection of propofol
time in seconds starting from injection of Propofol-lidocaine mixture until patient loose consciousness
2 minutes after start of injection of propofol
patient satisfaction
Time Frame: 30 minutes after recovery
describes satisfaction level of the patient regarding relief of propofol injection (not satisfied, less satisfied, satisfied, highly satisfied)
30 minutes after recovery
hand or forearm withdrawal
Time Frame: 2 minutes duration during injection of propofol
withdrawal due to pain during injection of propofol
2 minutes duration during injection of propofol

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

March 1, 2023

Primary Completion (Estimated)

December 1, 2023

Study Completion (Estimated)

December 1, 2023

Study Registration Dates

First Submitted

April 30, 2023

First Submitted That Met QC Criteria

June 7, 2023

First Posted (Actual)

June 12, 2023

Study Record Updates

Last Update Posted (Actual)

June 12, 2023

Last Update Submitted That Met QC Criteria

June 7, 2023

Last Verified

June 1, 2023

More Information

Terms related to this study

Other Study ID Numbers

  • Soh-Med-22-11-15

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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