Spinal Hypobaric Local Anesthetic Study

NCT ID: NCT06166394

Last Updated: 2025-03-28

Basic Information

• Recruitment Status: COMPLETED
• Total Enrollment: 60 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2023-06-09
• Study Completion Date: 2024-05-24

Brief Summary

The length of hospital stay after total hip and knee arthroplasty is determined based on the successful mobilization of the patients post surgery. Fast track pathways involving early mobilization and discharge of the patient on the same day of surgery, shortens the hospital stay and reduces the risk of adverse effects. The long acting LA (bupivacaine) is most commonly used in spinal anesthesia for arthroplasty surgeries and is associated with a prolonged motor and sensory block. In contrast, hypobaric bupivacaine and hypobaric mepivacaine helps in achieving the desired block level with smaller dosage and shorter onset time and faster recovery when compared to long acting local anesthetics. The aim of the study is to observe the effects of hypobaric local anesthetics ( bupivacaine and mepivacaine ) in patients undergoing unilateral total hip or knee arthroplasty in terms of time to onset and time to recovery of the block and also its effect on hemodynamic stability and time to mobilization after surgery. This study will allow the investigators to recommend optimal dosing strategies that in turn will help in faster recovery from spinal anesthesia and early mobilization thereby reducing harmful outcomes.

Detailed Description

Fast-track pathways involving same day mobilization and hospital discharge for total hip and knee arthroplasty are increasingly popular in modern orthopedic practice. Numerous reports have demonstrated the feasibility of this approach.

The choice of local anesthetic (LA) drug and dose administered in spinal anesthesia is determined by several considerations including the desired block height (the upper limit of sensory loss and surgical anesthesia that is achieved) and block duration. Block height and duration should be adequate for the surgery in question, but should ideally not be excessive, as they can lead to adverse effects including sympathetic blockade and hypotension, urinary retention, and delayed recovery of motor function in the lower limbs. The long-acting amide LA, bupivacaine, is most commonly used in this setting at Toronto Western Hospital (TWH) and elsewhere in the world. It is, however, associated with a prolonged motor and sensory recovery (4-6 hours). An alternative strategy to achieve adequate block height without using excessive doses of LA is to administer a hypobaric solution of bupivacaine or mepivacaine; this has been trialed with success at TWH and is now used routinely by staff anesthesiologists. Nevertheless, most of the investigator's knowledge regarding hypobaric LA solutions in spinal anesthesia comes from studies that are more than two decades old. There are no studies on mepivacaine, and neither hypobaric bupivacaine nor mepivacaine have been investigated in the context of fast-track total hip and knee arthroplasty pathways. In this context, the ideal LA solution used for spinal anesthesia should provide a consistent and fast onset time to achieve the required surgical anesthesia while the sensory and motor block should resolve as soon as possible after surgery. The investigators believe that hypobaric bupivacaine and hypobaric mepivacaine may satisfy these criteria and hence, the investigators aim to study their pharmacodynamics.

Conditions

Anesthesia, Local

Study Design

• Observational Model Type: COHORT
• Study Time Perspective: PROSPECTIVE

Study Groups

Mepivacaine

Day surgery patients(30 patients); For these patients- Administration of a spinal hypobaric mepivacaine injection

Spinal hypobaric Mepivacaine Local Anesthetic Injection

Intervention Type: DRUG

• Administration of a hypobaric spinal mixture for Day-Surgery patients: 3.4ml of 1.5% mepivacaine created by 3ml 2% mepivacaine with 1ml sterile water, and then discarding 0.6ml

Bupivacaine

In-patients(30 patients): For these patients- Administration of a spinal hypobaric bupivacaine injection

Spinal hypobaric Bupivacaine Local Anesthetic Injection

Intervention Type: DRUG

Administration of a hypobaric spinal mixture for In-patients:

3ml of 0.33% bupivacaine created by 2ml 0.5% bupivacaine with 1ml sterile water

Interventions

Spinal hypobaric Mepivacaine Local Anesthetic Injection

• Administration of a hypobaric spinal mixture for Day-Surgery patients: 3.4ml of 1.5% mepivacaine created by 3ml 2% mepivacaine with 1ml sterile water, and then discarding 0.6ml

Intervention Type: DRUG

Spinal hypobaric Bupivacaine Local Anesthetic Injection

Administration of a hypobaric spinal mixture for In-patients:

3ml of 0.33% bupivacaine created by 2ml 0.5% bupivacaine with 1ml sterile water

Intervention Type: DRUG

Other Intervention Names

Carbocaine; Marcaine

Eligibility Criteria

Inclusion Criteria

1. Patients undergoing elective unilateral total hip or knee arthroplasty under spinal anesthesia at Toronto Western Hospital

2. American Society of Anesthesiologists physical status class (ASA-PS) 1-3

3. Aged ≥ 20 years

Exclusion Criteria

1. Refusal to participate

2. Inability to communicate due to language barrier or cognitive impairment

3. Height < 150 cm or > 200 cm

4. Weight < 40 kg or >130 kg

5. Contraindication or allergy to amide-type local anesthetic

6. Contraindication to spinal anesthesia (e.g., infection at the injection site, existing coagulopathy)

7. Spinal anesthesia performed in the operating room rather than the block room (which will preclude adequate testing)

8. Spinal anesthesia that includes administration of intrathecal opioids (e.g., morphine, fentanyl),so as to avoid unanticipated alterations in block quality or solution baricities.

9. Pre-existing sensory or motor impairment in the lower extremities

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• Minimum Eligible Age: 20 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

University Health Network, Toronto

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Ki Jinn Chin, MD,FRCPC

Role: PRINCIPAL_INVESTIGATOR

UHN

Locations

Toronto Western Hospital

Toronto, Ontario, Canada

Countries

Canada

Other Identifiers

v04Nov2022

Identifier Type: OTHER

Identifier Source: secondary_id

22-5558

Identifier Type: -

Identifier Source: org_study_id