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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Retrospectively registered

Titles & IDs
Public title
A comparison of continuous and one-off interscalene block for pain relief following minor shoulder surgery.
Scientific title
A comparison of continuous and one-off interscalene block for postoperative analgesia following minor shoulder surgery.
Secondary ID [1] 259928 0
Nil Known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Patients requiring postoperative analgesia following minor shoulder surgery (subacromial decompression and stabilisation) 3509 0
Condition category
Condition code
Anaesthesiology 3663 3663 0 0
Other anaesthesiology

Study type
Description of intervention(s) / exposure
Interscalene block
A single operator Dr Michael Fredrickson (MF) will place all interscalene catheters (ISCs) in the operating room. Patients will be premedicated with oral acetaminophen 1 g, diclofenac SR 75 mg and omeprazole 20 mg one hour before surgery. Intravenous midazolam 2 mg, alfentanil 0.5 mg and cephazolin 1 g will be administered 5 min prior to interscalene catheter placement. Catheters will be placed following either the administration of a superficial cervical plexus block (SCPB) or after the induction of general anaesthesia depending on patient preference. ISCs will be placed using a combination of ultrasound and nerve stimulation.

General anaesthesia will then be administered and ropivacaine 0.5% 0.5 mL/kg to a maximum of 30 mL will be administered through the ISC.

Continuous block patients will then receive an ambulatory infusion of ropivacaine 0.2% at the end of surgery.
Intervention code [1] 3228 0
Treatment: Devices
Comparator / control treatment
Single shot patients will receive no infusion at the end of surgery.
Control group

Primary outcome [1] 4567 0
Reduced pain after minor shoulder surgery, assessed by patient interrogation regarding oral analgesic consumption and pain scores using numerical rating pain score (NRPS).
Timepoint [1] 4567 0
1-2 days post operatively.
Numerical rating pain score (NRPS) measured by Post Anaesthesia Care Unit (PACU) nurse on arrival in the PACU.
Oral analgesic requirements and pain scores (0-10) measured in the afternoon of Day 1 and Day 2 following surgery
Primary outcome [2] 5001 0
Arm numbness/weakness measured by patient numerical rating scale (0-10) on postoperative day 2 questionnaire.
Timepoint [2] 5001 0
First 48 hours
Secondary outcome [1] 7720 0
Chronic pain post shoulder surgery, assessed by written questionnaire (The DASH form, Institute for Work & Health 2006) completed by patient at 3 months post operatively.
Timepoint [1] 7720 0
Day 90 post operatively

Key inclusion criteria
Patients undergoing elective minor shoulder surgery under the anaesthetic care of the principal investigator.
Minimum age
No limit
Maximum age
No limit
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
1. Patient refusal / inability to consent, age no limits
2. Allergy amide local anaesthetic (LA) drugs
3. Existing neurological disorders / neuropathy of the operative extremity
4. Infection at site of needle puncture
5. Severe respiratory disease
6. Chronic opioid therapy
7. Patients intolerant of all non-steroidal anti-inflammatory drugs (NSAID).

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
A invitation to participate in the study will be posted to patients identified from the operating list. One preoperative phone call will be made by the research assistant to assess patient’s suitability for the study. At this stage participation in this study would be discussed with the patient. Post operatively, patients will be questioned by phone for some simple data for the first 2 days following surgery. All patients will have a follow-up phone call at 10 days (5-10 mins) and they will be asked to fill out another questionnaire at 3 months.
Patients will be assigned to one of the two groups by random number generator, and assignments delivered in a sealed opaque envelope.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
A computerised random number generator will be used to assign the patient to one of the 2 groups.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?

Intervention assignment
Other design features
Type of endpoint(s)
Statistical methods / analysis

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment outside Australia
Country [1] 1099 0
New Zealand
State/province [1] 1099 0

Funding & Sponsors
Funding source category [1] 3682 0
Government body
Name [1] 3682 0
Accident Compensation Corporation (ACC)
Address [1] 3682 0
P O Box 242
Wellington 6140
Country [1] 3682 0
New Zealand
Primary sponsor type
Dr Michael Fredrickson
Anaesthesia Institute
P O Box 109 199
Auckland 1149
New Zealand
Secondary sponsor category [1] 3306 0
Name [1] 3306 0
Address [1] 3306 0
Country [1] 3306 0

Ethics approval
Ethics application status
Ethics committee name [1] 5735 0
Northern X Regional Ethics Committee
Ethics committee address [1] 5735 0
Private Bag 92 522
Wellesley Street
Auckland 1141
Ethics committee country [1] 5735 0
New Zealand
Date submitted for ethics approval [1] 5735 0
Approval date [1] 5735 0
Ethics approval number [1] 5735 0

Brief summary
Acute postoperative pain is commonly severe after major shoulder surgery - with opioids being required for several days. There is increasing evidence that poorly treated acute postoperative pain is a predictor of chronic pain and therefore chronic disability. Further, evidence exists that preventing early postoperative pain reduces the risk of chronic pain. Continuous interscalene block (CISB) has been shown to provide better analgesia and patient satisfaction than opioids for rotator cuff surgery. It has also been shown to improve patient outcome. CISB has been successfully used in Auckland for 4 years, however, anaesthetists have had to base many aspects of the technique on personal opinion rather than evidence from high quality research. Although CISB has been shown to provide better analgesia and patient satisfaction than opioids for rotator cuff repair, it is unknown whether these benefits apply to less painful procedures such as arthroscopic stabilization and arthroscopic subacromial decompression. For both procedures, randomized trials comparing CISB with traditional opioid analgesia have not been conducted.
The purpose of the current study is to determine whether CISB provides better analgesia and patient satisfaction than traditional single shot interscalene block (the community standard) following minor shoulder procedures (subacromial decompression and stabilisation).
If the primary hypothesis is confirmed, this study will provide evidence supporting the use of continuous interscalene block for this surgery.
This may result in future patients experiencing less postoperative pain after minor shoulder surgery. Potential benefits might include a lower incidence of post shoulder surgery chronic pain.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 28809 0
Dr Michael Fredrickson
Address 28809 0
Anaesthesia Institute
P.O. Box 109 199
Auckland 1149
Country 28809 0
New Zealand
Phone 28809 0
+64 9 522 1117
Fax 28809 0
Email 28809 0
Contact person for public queries
Name 11966 0
Dr Michael Fredrickson
Address 11966 0
Anaesthesia Institute
P O Box 109 199
Auckland 1149
Country 11966 0
New Zealand
Phone 11966 0
+64 9 522 1117
Fax 11966 0
+64 9 522 1127
Email 11966 0
Contact person for scientific queries
Name 2894 0
Dr Michael Fredrickson
Address 2894 0
Anaesthesia Institute
P O Box 109 199
Auckland 1149
Country 2894 0
New Zealand
Phone 2894 0
+64 9 522 1117
Fax 2894 0
+64 9 522 1127
Email 2894 0

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary