Blood Levels of Local Anaesthetic in Knee Arthroplasty Using a Continuous Infusion Device (BLOCKS-II)

Golden Jubilee National Hospital

Status: Unknown

Conditions: Osteoarthritis, Knee

Treatments: Drug: Ropivacaine

Study type: Observational

Funder types: Other; Industry

Identifiers

NCT01935648

13/ANAES/02

Details and patient eligibility

About

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.

Full 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 hip 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.

Enrollment: 30 estimated patients

Sex: All

Ages: 65+ years old

Volunteers: Accepts Healthy Volunteers

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

Trial design

30 participants in 1 patient group

Ropivacaine

Description:

Injection of local anaesthetic (ropivacaine) into the knee joint following hip arthroplasty. Total dose 200mls of 0.2% ropivacaine or 400mg at the time of surgery. This will be followed by a continuous infusion of 10mls/hour 0.2% ropivacaine for the subsequent 24 hours.

Treatment:

Drug: Ropivacaine