Effect of ropivacaine concentration on duration for interscalene blocks given for arthroscopic shoulder surgery: a prospective randomised controlled trial

Status

Completed

Phases

Phase 4

Study type

Interventional

Source

ANZCTR

Registry ID

ACTRN12611000433909

Enrollment

140

Registered

2011-04-27

Start date

2012-01-24

Completion date

2016-12-22

Last updated

2026-07-20

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

None listed

Brief summary

Arthroscopic shoulder surgery may produce severe pain that is a challenge to control. Interscalene nerve blocks have been shown to be an excellent method of analgesia. It is not clear what concentration of local anaesthetic should be used for interscalene blocks to maximise pain relief and minimise side-effects. We aim to determine if lower compared to higher concentrations of ropivacaine (a local anaesthetic) can produce comparable pain relief duration with less side-effects.

Interventions

Patients undergoing elective arthroscopic shoulder surgery will receive an ultrasound guided interscalene nerve block with 20mls of a randomly allocated ropivacaine concentration. Arm 1 0.1% ropivacaine Arm 2 0.2% ropivacaine Arm 3 0.375% ropivacaine Arm 4 0.75% ropivacaine

Study design

Allocation

Randomised controlled trial

Intervention model

Parallel

Primary purpose

Treatment

Masking

Blinded (masking used) (Subject, Caregiver, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender

All

Age

18 Years to 80 Years

Healthy volunteers

Inclusion criteria

Elective arthroscopic shoulder surgery Age 18-80 years ASA 1-3

Exclusion criteria

Patient refusal Previous involvement in this study Contraindication to interscalene block (patient refusal, coagulopathy, sepsis, local infection, severe respiratory disease, allergy to ropivacaine) Upper limb neurological disease or deficits Opioid tolerance (defined as use of >30mg oral morphine/day or equivalent – fentanyl patch 12mcg/hr, buprenorphine 20mcg/hr, oxycodone >20mg/day) Contraindication to COX2 inhibitors/NSAIDs (renal impairment, NSAIDs/aspirin trigger asthma, active peptic ulcer disease, or allergy).

Outcome results