Clinical trial NCT01873313: Blood Levels of Local Anaesthetic in Knee Arthroplasty
Official title: Blood Levels of Local Anaesthetic in Knee Arthroplasty: A Pharmacological Study of Ropivacaine Blood Levels During the Caledonian Technique for Knee Arthroplasty
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Arthritis of Knee
Lead sponsor: Golden Jubilee National Hospital
Sponsor class: OTHER_GOV
Collaborators: name: B. Braun Medical Inc.
name: University of Strathclyde
First posted: 2013-06-10
Enrollment: 20
Sex: ALL
Minimum age (years): 65
Standard ages: OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: CASE_ONLY
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Patients undergoing elective knee joint replacement where they will be receiving the Caledonian technique

Brief summary: The primary goal is to evaluate ropivacaine blood concentrations during and after local anaesthetic (ropivacaine) infiltration - the Caledonian technique - for total knee replacement surgery. The investigators plan to measure these levels by testing blood samples taken over a timed period.

This will allow us to confirm whether the current regimen of local anaesthetic use is within safe limits.

Detailed description: Local anaesthetic (LA) toxicity may occur when the blood levels of a drug become particularly high. There is a need to confirm that the technique is safe to use. In addition, journal case reports may only describe serious side-effects of toxicity such as abnormal heart rhythms whilst more subtle clinical signs are rarely reported.

The investigators would like to study whether or not toxic levels may be approached in some patients or whether more subtle toxicity symptoms and signs are missed. For example, irregular heartbeat, low blood pressure or confusion/agitation.

Therefore, the investigators intend to study ropivacaine blood levels in patients receiving a total knee replacement in the Golden Jubilee National Hospital. A series of timed samples will be taken during the perioperative period. The anaesthesia and surgery will be performed as routine and no new treatment will be involved. Patient demographics, ropivacaine blood levels and clinical observations following LA administration will be collected.

Eligibility criteria: Inclusion Criteria:

* Male or female patients greater than 65 years of age

Exclusion Criteria:

* Patients with a known sensitivity/allergy to ropivacaine or amide-type local anaesthetics
* Patients who are not suitable for the Caledonian technique
* Patients who refuse or are unable to give consent
* Patients undergoing bilateral hip replacements
* Patients with known heart, liver or kidney failure

Primary outcomes:
measure: Plasma levels of ropivacaine
timeFrame: First 24 hours after surgery
Secondary outcomes:
measure: Clinical observations
timeFrame: First 24 hours after surgery
measure: Evidence of dysrrhythmias as measured by 24-hour Holter monitoring
timeFrame: First 24 hours after surgery
Other outcomes:
Locations:
city: Clydebank
country: United Kingdom
facility: Golden Jubilee National Hospital
state: West Dunbartonshire
Study officials:
affiliation: NHS Research Scotland
name: Michael Gill, MBChB
role: PRINCIPAL_INVESTIGATOR
References: