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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
In patients receiving regional anaesthesia of the arm for arteriovenous(AV) fistula surgery, can washout with normal saline increase the speed of resolution of the block after the surgery has been completed.
Scientific title
Reversing the effects of peripheral nerve block in patients undergoing AV fistula surgery using normal saline to "wash off" the block with 10mL of saline every 15 minutes following the surgery speed the offset of the block in terms of return of motor and sensory function.
Secondary ID [1] 293424 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Regional anaesthesia 305581 0
Condition category
Condition code
Anaesthesiology 304811 304811 0 0

Study type
Description of intervention(s) / exposure
Following completion of AV fistula surgery the patient is transferred to the recovery room. Here a recovery nurse will flush 10ml of normal saline down the peripheral nerve catheter every 15 minutes for one hour, in the intervention group, and the control group has nothing done to the catheter. A blinded observer then assesses the patients block, 4 times during the hour that the patient stays in recovery. They assess the motor and sensory function in the 4 major nerves of the arm, and assess the pain scores of the patient.
Intervention code [1] 299666 0
Treatment: Other
Comparator / control treatment
Control group has a peripheral nerve catheter, but no washout.
Control group

Primary outcome [1] 304021 0
Motor function is assessed with movements controlled by the 4 major nerves and graded on Bromage score of 0 to 5 depending on the strength of the movement.
Timepoint [1] 304021 0
There are 4 assessments of the patients block during their time in recovery. These are timed to be 5 minutes after the intervention (normal saline flush), in the intervention group and at the same time in the control group. This means the block is assessed when the patient first reaches recovery and then every 15 minutes for one hour.
Primary outcome [2] 304318 0
Sensory function of the forearm in terms of light touch and temperature sensation in the 4 nerve territories of the arm.
Timepoint [2] 304318 0
Every 15 minutes for 1 hour.
Primary outcome [3] 304319 0
Pain scores self reported by the patient on scale of 1-10.
Timepoint [3] 304319 0
Every 15 minutes for one hour.
Secondary outcome [1] 341572 0
Timepoint [1] 341572 0

Key inclusion criteria
• Provide informed written consent
• Adult (18 years or older) patients
• Having AV fistula formation under brachial plexus block
The patients block is measured on first admission to recovery room, and then every 15 minutes for one hour while in the recovery room. AV fistula patients are routinely discharged home after one hour in recovery.
Minimum age
18 Years
Maximum age
No limit
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
• Failure to provide informed consent
• Infection at the needle insertion site
• Known coagulopathy
• Known allergy to local anesthetics
• Presence of sensory or motor impairment in the distribution of the brachial plexus prior to nerve blockade
• Inability to perform valid sensory or motor assessment due to impaired access to the limb, language barrier, or inability of the subject to co-operate with such examination

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
20 patients will be allocated to each group, so 40 slips of paper containing the group allocation will be placed into envelopes that will be drawn randomly from a box when a patient is recruited into the study.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Randomly drawn envelope.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?

The people assessing the outcomes
Intervention assignment
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
Data will be recorded on a data sheet and transferred to an Excel spreadsheet for statistical analysis. Comparisons between groups will be performed with Student’s t-test. Qualitative data will be reported as either absolute numbers or percentage and will be analyzed by Chi-square analysis or Fisher’s exact test, whichever is appropriate. A p value of < 0.05 will be considered statistically significant.

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] 9390 0
New Zealand
State/province [1] 9390 0

Funding & Sponsors
Funding source category [1] 298049 0
Name [1] 298049 0
Waikato hospital
Address [1] 298049 0
Dept. of Anaesthesia
Waikato hospital
Pembroke Street
Hamilton 3200
Country [1] 298049 0
New Zealand
Primary sponsor type
Waikato hospital
Pembroke Street
Hamilton 3200
New Zealand
Secondary sponsor category [1] 297123 0
Name [1] 297123 0
Address [1] 297123 0
Country [1] 297123 0

Ethics approval
Ethics application status
Ethics committee name [1] 299071 0
Northern B Ethics committee
Ethics committee address [1] 299071 0
Health and Disability Ethics Committees
Ministry of Health
C/- MEDSAFE, Level 6, Deloitte House
10 Brandon Street
PO Box 5013
Ethics committee country [1] 299071 0
New Zealand
Date submitted for ethics approval [1] 299071 0
Approval date [1] 299071 0
Ethics approval number [1] 299071 0

Brief summary
Background and rationale
Peripheral nerve blocks provide effective surgical anesthesia targeted to specific body regions while avoiding the unpleasant side-effects of general anesthesia.
There are occasions when rapid and effective block reversal is needed. For example, interscalene brachial plexus block for upper extremity surgery frequently causes paralysis of the diaphragm due to inadvertent anesthesia of the phrenic nerve. A method to ‘wash out’ the local anesthetic around the phrenic nerve in these cases would be beneficial, Or in cases where patients are being discharged home the same day, and normal motor and sensory function of the limb in beneficial.
Several studies have demonstrated that epidural washout using normal saline (NS) or Ringer’s lactate following epidural block facilitates more rapid recovery of motor function and sensation than letting the block resolve on its own. However, no studies to date have addressed whether washout is effective for reversal of peripheral nerve blocks. A recently published report suggests that a bolus of NS through a perineural catheter can rapidly and effectively restore phrenic nerve function following interscalene block.

Study objective
To demonstrate that infusion bolus of NS can be used in a clinical setting to modify the properties of a nerve block in patients who have received a nerve block for surgery and are expected to have minimal pain post operatively.

We hypothesize that NS can be delivered through a perineural catheter to ‘wash out’ a nerve block to the point that function of the nerves returns. .
Trial website
Trial related presentations / publications
Smith C, Byrne K, Termaat J, Tsui B. A simple method to reverse peripheral nerve blockade. Poster presentation at the NZ Anaesthesia Annual Scientific Meeting, Rotorua, November 8-11, 2017.
Public notes

Principal investigator
Name 79194 0
Dr Kelly Byrne
Address 79194 0
Dept. of Anaesthesia
Waikato hospital
Pembroke Street
Hamilton 3200
New Zealand
Country 79194 0
New Zealand
Phone 79194 0
Fax 79194 0
Email 79194 0
Contact person for public queries
Name 79195 0
Dr Kelly Byrne
Address 79195 0
Dept. of Anaesthesia
Waikato hospital
Pembroke Street
Hamilton 3200
New Zealand
Country 79195 0
New Zealand
Phone 79195 0
Fax 79195 0
Email 79195 0
Contact person for scientific queries
Name 79196 0
Dr Kelly Byrne
Address 79196 0
Dept. of Anaesthesia
Waikato hospital
Pembroke Street
Hamilton 3200
New Zealand
Country 79196 0
New Zealand
Phone 79196 0
Fax 79196 0
Email 79196 0

No data has been provided for results reporting
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