Comparison of Different Epidural Lidocaine-Bupivacaine Mixtures for Lower Limb Surgeries (LBM-LLS)

Comparison of the Outcomes of Epidural Injection of Different Lidocaine-Bupivacaine Mixtures for Lower Limb Surgeries at a Tertiary Care Hospital, Karachi

This randomized controlled trial will evaluate different epidural lidocaine-bupivacaine mixtures in patients undergoing lower limb surgery at a tertiary care hospital in Karachi, Pakistan. Ninety-six participants will be randomly assigned to one of three study groups receiving different combinations of lidocaine and bupivacaine for epidural anesthesia.

The purpose of this study is to determine which anesthetic mixture provides the most effective anesthesia for lower limb surgery. The study will compare the speed of onset and duration of anesthesia, as well as the effects of the anesthetic mixtures on cardiovascular stability during surgery.

The results of this study may help identify an epidural anesthetic regimen that provides optimal surgical conditions, effective pain control, and stable hemodynamic parameters for patients undergoing lower limb procedures.

Study Overview

• Status: Recruiting
• Conditions: Epidural Dosage of Lidocaine Bupivacaine in Lower Limb Surgeries
• Intervention / Treatment: Drug: Lidocaine-Bupivacaine Epidural Mixture (High-dose Lidocaine)

Detailed Description

Lower limb surgeries are commonly associated with significant perioperative and postoperative pain, requiring effective anesthetic techniques to provide adequate analgesia and improve patient outcomes. Epidural anesthesia is widely used because it offers effective intraoperative anesthesia, prolonged postoperative pain relief, improved physiological responses to surgical stress, and enhanced patient satisfaction. Local anesthetic agents such as lidocaine and bupivacaine are commonly administered for epidural blockade due to their different pharmacological characteristics.

Lidocaine has a rapid onset of action but a relatively shorter duration, whereas bupivacaine provides prolonged analgesia but has a slower onset of action. Combining these agents may provide the advantages of both drugs by achieving rapid onset with longer duration of action while maintaining hemodynamic stability.

This randomized controlled trial will be conducted at the Department of Anaesthesiology and Surgical ICU, Shaheed Mohtarma Benazir Bhutto Institute of Trauma, Karachi. Ninety-six patients aged 20-60 years, ASA class I and II, undergoing lower limb surgeries under epidural anesthesia will be enrolled and randomized equally into three groups.

Group A: 10 ml of 0.5% isobaric bupivacaine + 5 ml of 2% lidocaine Group B: 10 ml of 0.5% isobaric bupivacaine + 2.5 ml of 2% lidocaine + 2.5 ml normal saline Group C: 10 ml of 0.5% isobaric bupivacaine + 5 ml normal saline

The primary outcomes assessed will include time to onset of sensory blockade at T10 level, time to onset of motor blockade to Bromage Grade II, and duration of motor blockade until recovery to Bromage Grade I. Hemodynamic variables including mean arterial pressure and heart rate will also be recorded and compared among groups.

The study aims to determine the optimal epidural lidocaine-bupivacaine mixture that provides faster onset of anesthesia, adequate duration of block, and stable hemodynamic effects in patients undergoing lower limb surgeries.

• Study Type: Interventional
• Enrollment (Estimated): 96
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Tooba Azfar Hussain, MBBS; Phone Number: 03357192306; Email: toobster1996@gmail.com

Study Locations

• Pakistan
  • Sindh
    • Karachi, Sindh, Pakistan, 75290
      • Recruiting
      • Shaheed Mohtarma Benazir Bhutto Institute of Trauma
      • Contact: Tooba Azfar Hussain, MBBS; Phone Number: 03357192306; Email: toobster1996@gmail.com
      • Contact: Email: toobster1996@gmail.com
      • Principal Investigator: Tooba Azfar Hussain, MBBS

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

Patients undergoing lower limb surgeries under epidural block Age between 20-60 years Either gender American Society of Anesthesiologists (ASA) physical status I and II Patients willing to provide informed consent

Exclusion Criteria:

Contraindications to regional anesthesia including patient refusal and bleeding diathesis History of allergy to local anesthetics Patients undergoing emergency surgeries Deformities of the spine History of hypothyroidism or hyperthyroidism Pregnant patients

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Group A - High-dose Lidocaine-Bupivacaine Mixture; Group A High-dose Lidocaine-Bupivacaine Mixture Participants will receive epidural administration of 10 ml of 0.5% isobaric bupivacaine mixed with 5 ml of 2% lidocaine (total volume 15 ml).	Drug: Lidocaine-Bupivacaine Epidural Mixture (High-dose Lidocaine); Intervention 1: Lidocaine-Bupivacaine Epidural Mixture (High-dose Lidocaine) Epidural administration of a total volume of 15 ml containing 10 ml of 0.5% isobaric bupivacaine and 5 ml of 2% lidocaine for anesthesia during lower limb surgery. Intervention 2: Lidocaine-Bupivacaine Epidural Mixture (Low-dose Lidocaine) Epidural administration of a total volume of 15 ml containing 10 ml of 0.5% isobaric bupivacaine, 2.5 ml of 2% lidocaine, and 2.5 ml of normal saline for anesthesia during lower limb surgery. Intervention 3: Bupivacaine Epidural Mixture (Control) Epidural administration of a total volume of 15 ml containing 10 ml of 0.5% isobaric bupivacaine and 5 ml of normal saline for anesthesia during lower limb surgery. These descriptions clearly distinguish the three interventions by composition and total volume.; Other Names: Lidocaine-Bupivacaine Epidural Mixture (Low-dose Lidocaine); Bupivacaine Epidural Mixture (Control)
Experimental: Group B - Low-dose Lidocaine-Bupivacaine Mixture; Group B - Low-dose Lidocaine-Bupivacaine Mixture Participants will receive epidural administration of 10 ml of 0.5% isobaric bupivacaine mixed with 2.5 ml of 2% lidocaine and 2.5 ml normal saline (total volume 15 ml).	Drug: Lidocaine-Bupivacaine Epidural Mixture (High-dose Lidocaine); Intervention 1: Lidocaine-Bupivacaine Epidural Mixture (High-dose Lidocaine) Epidural administration of a total volume of 15 ml containing 10 ml of 0.5% isobaric bupivacaine and 5 ml of 2% lidocaine for anesthesia during lower limb surgery. Intervention 2: Lidocaine-Bupivacaine Epidural Mixture (Low-dose Lidocaine) Epidural administration of a total volume of 15 ml containing 10 ml of 0.5% isobaric bupivacaine, 2.5 ml of 2% lidocaine, and 2.5 ml of normal saline for anesthesia during lower limb surgery. Intervention 3: Bupivacaine Epidural Mixture (Control) Epidural administration of a total volume of 15 ml containing 10 ml of 0.5% isobaric bupivacaine and 5 ml of normal saline for anesthesia during lower limb surgery. These descriptions clearly distinguish the three interventions by composition and total volume.; Other Names: Lidocaine-Bupivacaine Epidural Mixture (Low-dose Lidocaine); Bupivacaine Epidural Mixture (Control)
Active Comparator: Group C - Bupivacaine Control Group; Group C Participants will receive epidural administration of 10 ml of 0.5% isobaric bupivacaine mixed with 5 ml normal saline (total volume 15 ml).	Drug: Lidocaine-Bupivacaine Epidural Mixture (High-dose Lidocaine); Intervention 1: Lidocaine-Bupivacaine Epidural Mixture (High-dose Lidocaine) Epidural administration of a total volume of 15 ml containing 10 ml of 0.5% isobaric bupivacaine and 5 ml of 2% lidocaine for anesthesia during lower limb surgery. Intervention 2: Lidocaine-Bupivacaine Epidural Mixture (Low-dose Lidocaine) Epidural administration of a total volume of 15 ml containing 10 ml of 0.5% isobaric bupivacaine, 2.5 ml of 2% lidocaine, and 2.5 ml of normal saline for anesthesia during lower limb surgery. Intervention 3: Bupivacaine Epidural Mixture (Control) Epidural administration of a total volume of 15 ml containing 10 ml of 0.5% isobaric bupivacaine and 5 ml of normal saline for anesthesia during lower limb surgery. These descriptions clearly distinguish the three interventions by composition and total volume.; Other Names: Lidocaine-Bupivacaine Epidural Mixture (Low-dose Lidocaine); Bupivacaine Epidural Mixture (Control)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time to Onset of Sensory Blockade	Time from completion of epidural injection until development of sensory block at the T10 dermatome level, measured in minutes using the cold swab test.	From completion of epidural injection until achievement of sensory block at the T10 dermatome level, assessed up to 20 minutes.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time to Onset of Motor Blockade	Time from completion of epidural injection until the patient develops Bromage Grade II motor blockade, measured in minutes.	From completion of epidural injection until achievement of Bromage Grade II motor blockade, assessed up to 20 minutes.
Duration of Motor Blockade	Time from achievement of Bromage Grade II motor blockade until complete recovery of motor function (Bromage Grade 0), measured in minutes.	From achievement of Bromage Grade II motor blockade until complete recovery of motor function, assessed up to 8 hours after epidural injection.
Mean Arterial Pressure	Mean arterial pressure will be recorded every 3 minutes for the first 30 minutes and then every 5 minutes until completion of surgery.	From epidural injection until completion of surgery, assessed up to 3 hours.
Heart Rate	Heart rate will be continuously monitored throughout the procedure and recorded at predefined intervals during surgery.	From epidural injection until completion of surgery, assessed up to 3 hours.

Collaborators and Investigators

• Sponsor: Shaheed Mohtarma Benazir Bhutto Institue of Trauma

Study record dates

Study Major Dates

• Study Start (Actual): December 18, 2025
• Primary Completion (Actual): May 20, 2026
• Study Completion (Estimated): June 15, 2026

Study Registration Dates

• First Submitted: June 7, 2026
• First Submitted That Met QC Criteria: June 12, 2026
• First Posted (Actual): June 15, 2026

Study Record Updates

• Last Update Posted (Actual): June 15, 2026
• Last Update Submitted That Met QC Criteria: June 12, 2026
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: Epidural, Lidocaine, Bupivacaine, lower limb surgeries
• Additional Relevant MeSH Terms: Organic Chemicals; Anilides; Amides; Aniline Compounds; Amines; Acetanilides; Lidocaine
• Other Study ID Numbers: THussain; SMBBIT (Other Identifier: SMBBIT)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No