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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Date data sharing statement initially provided
Date results information initially provided
Type of registration
Prospectively registered

Titles & IDs
Public title
Does erector spinae block effect somatosensory evoked potentials in volunteers?
Scientific title
Does erector spinae block(ESB) effect somatosensory evoked potentials (SSEPs) in healthy volunteers?
Secondary ID [1] 296351 0
Nil known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Analgesia 310078 0
Condition category
Condition code
Anaesthesiology 308828 308828 0 0
Pain management

Study type
Description of intervention(s) / exposure
10 healthy volunteers will have a single shot erector spinae block administered by an experienced regional anaesthetist. The block will be undertaken in the recovery room with the usual ANZCA mandated monitoring for a major regional anaesthesia block (ECG, BP and pulse oximetry). 30ml of 0.375% ropivacaine will be used for the erector spinae block which will be undertaken under ultrasound guidance, with the local injected under the erector spinae muscles at the T4-T5 level. Somatasensory evoked potentials will be measured in the dermatomes, at the level of the block and 3 levels either side of the block, to account for potential spread of the block. The somatosensory evoked potential monitoring will be undertaken by a neurophysiology company experienced in the monitoring of somatosensory evoked potentials for spinal surgery.
Intervention code [1] 312685 0
Treatment: Other
Intervention code [2] 312741 0
Treatment: Drugs
Comparator / control treatment
No control group.
Control group

Primary outcome [1] 307802 0
Amplitude of somatosensory evoked potentials at the dermatomal level of the erector spinae block as assessed by stimulation of the intercostal nerves with a constant current generator and assessed by scalp electrode monitoring of the electroencephalogram.
Timepoint [1] 307802 0
Baseline, 15 minutes and 30 minutes after institution of the block
Secondary outcome [1] 352962 0
Following institution of the erector spinae block, changes in the participants sensory response to an ice pack will be mapped out, the patient will report where the sensation is altered to determine the extent of the block. The dermatomal innervation of the skin is well known, and therefore the extent of the block can be determined by a reduction in the sensation of cold, when an ice pack is pressed to the skin. This is a well recognised way of assessing regional anaesthesia efficacy (e.g. in patients with an epidural), and will be undertaken by experienced recovery nurses.
Timepoint [1] 352962 0
15 and 30 minutes after institution of the block

Key inclusion criteria
Healthy volunteers who have no contraindication to receiving local anaesthetic or an erector spinae block and who have signed written consent.
Minimum age
18 Years
Maximum age
65 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Allergy to local anaesthetic
Infection at the site of proposed nerve block

Study design
Purpose of the study
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Nil required
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Nil required
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?

Intervention assignment
Single group
Other design features
Phase 4
Type of endpoint(s)
Statistical methods / analysis
Descriptive statistics only, percentage of patients were SSEPs are abolished, and dermatomal spread of the block in each subject.

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] 20938 0
New Zealand
State/province [1] 20938 0

Funding & Sponsors
Funding source category [1] 300956 0
Name [1] 300956 0
The Waikato hospital department of anaesthesia research fund
Address [1] 300956 0
Department of Anaesthesia
Level 4 Waiora buliding
Waikato hospital
Pembroke Street
Hamilton 3204
New Zealand
Country [1] 300956 0
New Zealand
Primary sponsor type
Waikato hospital
Pembroke Street
Hamilton 3204
New Zealand
New Zealand
Secondary sponsor category [1] 300528 0
Name [1] 300528 0
Address [1] 300528 0
Country [1] 300528 0

Ethics approval
Ethics application status
Ethics committee name [1] 301721 0
National Health and Disability Ethics Committee
Ethics committee address [1] 301721 0
Ministry of Health
Health and Disability Ethics Committees
PO Box 5013
Wellington 6140
Ethics committee country [1] 301721 0
New Zealand
Date submitted for ethics approval [1] 301721 0
Approval date [1] 301721 0
Ethics approval number [1] 301721 0

Brief summary
The erector spinae block is a newly described regional anaesthetic technique which has the potential to be applied to a wide range of surgeries. It is potentially an alternative to a paravertebral block, an older, effective but much more technically difficult block. One of the benefits of the paravertebral block is that it profoundly blocks the somatosensory evoked potentials of the area that it provides analgesia to[Richardson, et al. The Effect of thoracic paravertebral blockade on Intercostal somatosensory evoked potentials. Anesth Analg 1998:87;373-76]. This potentially reduces the stress response to surgery, and the likelihood of chronic pain following surgery.
For the erector spinae block to replace the paravertebral block in clinical practice, it is important to show that it is not only equivalent in terms of analgesia, but should also be equivalent in its ability to block the somatosensory evoked potentials.
The aim of this study is to determine whether or not the erector spinae block effects somatosensory evoked potentials in healthy volunteers.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 87882 0
Dr Kelly Byrne
Address 87882 0
Department of Anaesthesia
Level 4 Waiora Building
Waikato Hospital
Hamilton 3204
New Zealand
Country 87882 0
New Zealand
Phone 87882 0
+64 2102224390
Fax 87882 0
Email 87882 0
Contact person for public queries
Name 87883 0
Dr Kelly Byrne
Address 87883 0
Department of Anaesthesia
Level 4 Waiora Building
Waikato Hospital
Hamilton 3204
New Zealand
Country 87883 0
New Zealand
Phone 87883 0
+64 2102224390
Fax 87883 0
Email 87883 0
Contact person for scientific queries
Name 87884 0
Dr Kelly Byrne
Address 87884 0
Department of Anaesthesia
Level 4 Waiora Building
Waikato Hospital
Hamilton 3204
New Zealand
Country 87884 0
New Zealand
Phone 87884 0
+64 2102224390
Fax 87884 0
Email 87884 0

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No/undecided IPD sharing reason/comment
What supporting documents are/will be available?
No other documents available
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