Hyperbaric Bupivacaine Versus Hyperbaric Prilocaine in Spinal Anaesthesia

A Prospective, Double-blinded, Randomised Controlled Trial Comparing the Use of Hyperbaric Bupivacaine Versus Hyperbaric Prilocaine for Spinal Anaesthesia in Asian Patients Undergoing Elective Total Knee Replacement

Prilocaine numbs you for a shorter time, allowing you to regain movement quicker, which helps you recover faster, start rehab sooner, and feel more satisfied with your treatment overall.

Study Overview

• Status: Active, not recruiting
• Conditions: Knee Replacement, Total; Knee Replacement Surgery
• Intervention / Treatment: Drug: prilocaine; Drug: Bupivacaine

Detailed Description

Bupivacaine has long been the go-to choice for spinal anesthesia in total knee replacement surgeries due to its effectiveness in providing surgical anesthesia. However, it comes with some drawbacks, primarily its prolonged motor block and the potential for dose-related hypotension, which can hinder post-operative recovery. In contrast, prilocaine has gained popularity in recent years, particularly for outpatient procedures and even caesarean sections. Prilocaine's appeal lies in its faster recovery profile, characterized by a shorter duration of motor block and reduced incidence of urinary retention. These properties make it an attractive option for total knee replacement patients, as it potentially allows for quicker rehabilitation. The shorter-acting nature of prilocaine means patients may regain mobility sooner, potentially leading to earlier discharge and improved overall satisfaction. Despite these promising attributes, there's a notable gap in research comparing the intrathecal use of hyperbaric prilocaine 2% with hyperbaric bupivacaine 0.5%, especially within the Asian population. This lack of comparative studies highlights the need for further investigation to determine if prilocaine's benefits observed in other contexts translate effectively to total knee replacement procedures in Asian patients, potentially offering a pathway to enhanced recovery protocols in this specific demographic.

• Study Type: Interventional
• Enrollment (Actual): 50
• Phase: Phase 4

Contacts and Locations

Study Locations

• Singapore
  • Singapore, Singapore, 119074
    • National University Hospital Singapore

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• undergoing elective unilateral total knee replacement
• Able to give informed consent

Exclusion Criteria:

• Patients of age < 21 or > 90 years old
• American Society of Anaesthesiologists (ASA) physical status> III
• Extremes of weight: <40kg or BMI >40
• Contra-indications to spinal anaesthesia, prilocaine or bupivacaine (including allergy to local anaesthesia agents or patients at high risk for methaemoglobinemia)
• Complex TKR as deemed by surgeons
• Patient refusal
• Failure of spinal anaesthesia resulting in conversion to general anaesthesia, prior to start of operation
• Patients with prostate hyperplasia or urogenital pathologies
• Planning to conceive / pregnant women / breastfeeding

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Supportive Care
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: bupivacaine; The administration of the spinal anesthetic will follow the hospital's standard protocol for this procedure. This means that apart from the specific local anesthetic used (prilocaine or bupivacaine), all other aspects of the anesthesia process - including patient preparation, sterile technique, needle size and type, patient positioning, and post-procedure care - will remain consistent with the hospital's established guidelines for spinal anesthesia	Drug: prilocaine; Prilocaine is known to have a faster recovery time by producing a shorter duration of motor block and less urinary retention, this results in a more rapid rehabilitation in post-total knee replacement surgical patients
Active Comparator: prilocaine; The administration of the spinal anesthetic will follow the hospital's standard protocol for this procedure. This means that apart from the specific local anesthetic used (prilocaine or bupivacaine), all other aspects of the anesthesia process - including patient preparation, sterile technique, needle size and type, patient positioning, and post-procedure care - will remain consistent with the hospital's established guidelines for spinal anesthesia	Drug: Bupivacaine; Bupivacaine has long been the go-to choice for spinal anesthesia in total knee replacement surgeries due to its effectiveness in providing surgical anesthesia

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Duration of Motor Block	This study will measure the duration of motor block, defined as the time from spinal anesthesia administration to full recovery of motor function. Motor function will be assessed using the modified Bromage scale, with full recovery defined as a Bromage score of 0 (full movement of legs and feet). The primary hypothesis is that prilocaine will produce an effective sensory block while resulting in a significantly shorter duration of motor block compared to bupivacaine. Assessments will be conducted at regular intervals following the administration of spinal anesthesia until full motor recovery is achieved, with an expected timeframe of up to 24 hours post-operation. This outcome measure will help determine the comparative efficacy of prilocaine versus bupivacaine in facilitating earlier mobilization and potentially enhancing post-operative recovery in patients undergoing total knee replacement surgery.	Measured from the time of spinal anesthesia administration until full motor recovery, expected within 24 hours post-operation.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Comparison of Side Effects between Prilocaine and Bupivacaine	The study will assess the overall incidence and severity of anesthesia-related adverse events associated with intrathecal prilocaine and bupivacaine in patients undergoing total knee replacement surgery. The measure encompasses a comprehensive range of potential physiological, neurological, and systemic reactions typically associated with spinal anesthesia and local anesthetic use.	From spinal anesthesia administration up to 24 hours post-operation.

Collaborators and Investigators

• Sponsor: National University Hospital, Singapore
• Investigators: Principal Investigator: Jasmin Jeanette Tan, National University Hospital, Singapore

Study record dates

Study Major Dates

• Study Start (Actual): May 17, 2024
• Primary Completion (Actual): December 1, 2025
• Study Completion (Estimated): June 1, 2026

Study Registration Dates

• First Submitted: December 21, 2025
• First Submitted That Met QC Criteria: January 6, 2026
• First Posted (Actual): January 9, 2026

Study Record Updates

• Last Update Posted (Actual): January 9, 2026
• Last Update Submitted That Met QC Criteria: January 6, 2026
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: total knee replacement; spinal anaesthesia; Prilocaine; Bupivacaine
• Additional Relevant MeSH Terms: Organic Chemicals; Anilides; Amides; Aniline Compounds; Amines; Bupivacaine; Prilocaine
• Other Study ID Numbers: 2023/00591

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