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Trial registered on ANZCTR

Registration number

ACTRN12614000343606

Ethics application status

Approved

Date submitted

23/03/2014

Date registered

31/03/2014

Date last updated

17/03/2016

Type of registration

Prospectively registered

Titles & IDs

Public title

A Randomised Trial of the Effectiveness of Different in vitro Models in Teaching Ultrasound Guided Regional Anaesthesia

Scientific title

Novices in ultrasound guided regional anaesthesia will be randomised to receive deliberate practice training on either low fidelity meat model or high fidelity cadaveric model to determine the effectiveness of the 2 different in vitro models in learning technical tasks in ultrasound guided regional anaesthesia.

Secondary ID [1]

None

Universal Trial Number (UTN)

U1111-1154-8451

Trial acronym

Linked study record

Health condition

Health condition(s) or problem(s) studied:

education in ultrasound guided regional anaesthesia

Condition category

Condition code

Anaesthesiology

Anaesthetics

Intervention/exposure

Study type

Interventional

Description of intervention(s) / exposure

Volunteers who are novices in ultrasound guided regional anaesthesia are randomised to 2 equal groups, called Group M (meat model) and Group C (cadaver model). Group C will be the intervention for this randomised controlled trial.
These models represent in vitro training models currently used for training. Both Groups will receive deliberate practice training and feedback after each attempt (total 30 attempts), delivered by a faculty with expertise in ultrasound guided regional anaesthesia. The feedback involves specific training in ultrasound guidance, needle visibility, transducer movements, and image quality techniques.
Performance of each group is scored at the end of the 30 attempts using a previously published objective assessment tool, testing efficiency, proficiency, and error rates of ultrasound guided regional anaesthesia.
The study will be performed over a single day, with break sessions scheduled to reduce risk of fatigue

Intervention code [1]

Other interventions

Comparator / control treatment

low fidelity meat model, composed of a fresh pork phantom with tendons inserted longitudinally to simulate nerves. Will receive the same deliberate practice and feedback over 30 attempts, with the study performed over a single day with scheduled breaks to minimise risk of fatigue

Control group

Active

Outcomes

Primary outcome [1]

Time taken (seconds) from insertion of the needle using an in-plane technique (maintaining visualisation of needle shaft and tip) to the 6 o’clock and 12 o’clock positions of the target, and injecting 0.5mls of saline at each position. Two blinded assessors will independently mark each participant.

Timepoint [1]

performance of task after 30 practice attempts

Secondary outcome [1]

Number of needle passes. Two blinded assessors will independently mark each participant.

Timepoint [1]

performance after 30 practice attempts

Secondary outcome [2]

Number of errors during performance of task. Two blinded assessors will independently mark each participant.

Timepoint [2]

performance after 30 practice attempts

Secondary outcome [3]

Image quality score of best sonoanatomical image. Two blinded assessors will independently mark each participant.

Timepoint [3]

performance of task after 30 practice attempts

Eligibility

Key inclusion criteria

adults, enrolled in an undergraduate or postgraduate health sciences degree (eg. medicine, nursing, physiotherapy, occupational therapy, medical science).
No previous experience or exposure to ultrasound guided procedures, or training in diagnostic ultrasound

Minimum age

18 Years

Maximum age

No limit

Sex

Both males and females

Can healthy volunteers participate?

Yes

Key exclusion criteria

Any previous experience or training in ultrasound

Study design

Purpose of the study

Educational / counselling / training

Allocation to intervention

Randomised controlled trial

Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)

sealed opaque envelopes numbered 1 to 50, 25 each containing either Group M or Group C

Methods used to generate the sequence in which subjects will be randomised (sequence generation)

simple randomisation using a computerised sequence generation

Masking / blinding

Blinded (masking used)

Who is / are masked / blinded?

The people assessing the outcomes
The people analysing the results/data

Intervention assignment

Parallel

Other design features

Phase

Not Applicable

Type of endpoint/s

Efficacy

Statistical methods / analysis

Two sided two sample t tests will be performed for the primary outcome of times taken between the two groups. 2 sample t tests will be performed for baseline and post-training performances within groups, and paired t tests will be performed on secondary outcomes with a more stringent significance of 0.01 to account for multiple comparisons. If data exhibits right skewness then the analyses will be performed on natural logarithm transformed data.

Recruitment

Recruitment status

Completed

Date of first participant enrolment

Anticipated

30/05/2015

Actual

30/05/2015

Date of last participant enrolment

Anticipated

Actual

30/05/2015

Date of last data collection

Anticipated

Actual

Sample size

Target

Accrual to date

Final

Recruitment in Australia

Recruitment state(s)

NSW

Recruitment hospital [1]

Macquarie University Hospital - Macquarie Park

Recruitment postcode(s) [1]

2109 - Macquarie University

Funding & Sponsors

Funding source category [1]

Charities/Societies/Foundations

Name [1]

Australian Society of Anaesthetists

Address [1]

PO Box 6278
North Sydney
NSW 2059

Country [1]

Australia

Primary sponsor type

University

Name

Australian School of Advanced Medicine, Macquarie University

Address

2 Technology Place
Macquarie University
NSW 2109

Country

Australia

Secondary sponsor category [1]

None

Name [1]

Address [1]

Country [1]

Ethics approval

Ethics application status

Approved

Ethics committee name [1]

Macquarie University Human Sciences HREC

Ethics committee address [1]

Research Office 
Level 3, Research HUB, Building C5C East
Macquarie University 
NSW 2109

Ethics committee country [1]

Australia

Date submitted for ethics approval [1]

30/03/2014

Approval date [1]

05/08/2014

Ethics approval number [1]

Summary

Brief summary

BACKGROUND
Ultrasound guided regional anaesthesia (UGRA) is a complex component of anaesthesia practice to learn. UGRA has evidence of improved safety, efficacy and is considered standard of care for peripheral nerve blocks. 
  To safely practice UGRA, procedural accuracy is required when introducing the nerve block needle into the patient and guiding that needle to the target nerve structure under real time ultrasound guidance. This procedural task encompasses several domains of knowledge and manual dexterity skills:
1. Ability to manipulate the ultrasound transducer to visualise and optimise the nerve and surrounding tissue sonoanatomy 
2. Ability to plan a needle path trajectory that maintains an in-plane visualisation of the needle shaft and tip from skin surface to deeper structures
3. Motor skill ability to guide the needle under real time visualisation to inject local anaesthesia at positions around the nerve to create a circumferential deposition of injectate (local anaesthesia)
4. Ability to recognise an optimal spread of injectate and to correct the needle position appropriately

Successful performance of UGRA thus requires hand-eye coordination and needle guidance techniques to maximise efficacy while minimising potential complications. 

Learning curve patterns of novices performing UGRA in patients has revealed an initial high rate of errors, from a mean of 12.6 errors per block during the first 10 attempts, decreasing to 4.6 errors per block by the end of the 39th attempt. In a study using cadavers, 28 UGRA attempts were required to reach competency as defined by needle visualisation under ultrasound and transducer steadiness. Both studies revealed wide variability in novices' error and success rates. This suggests that UGRA skills are difficult to master and individuals reach proficiency at different times, due to innate psychomotor abilities. 
  For ethical reasons, initial teaching of these procedural skills has thus focused on in vitro models. It allows repeated practice of high stakes procedural skills without risk of patient harm. It concentrates trainees and trainers in a single learning environment. A curriculum can be devised without distractions of clinical duties as occurs in hospital-based teaching.

The ideal in vitro model should be inexpensive, has similar properties to human tissue both under ultrasound (echogenicity, fascial planes, muscle texture, hyperechoic peripheral nerves, arterial and venous blood vessels that collapse appropriately under pressure, spread of injectate along fascial planes and around nerves, swelling of the nerve sheath if an intraneural injection was performed), as well as tactile feedback of resistance and fascial plane pops when a facet tipped nerve block needle is used. 
  Commonly used in vitro models include the gelatin model, meat model, and fresh frozen human cadaveric model. None of these satisfy as an ideal model, and all have advantages and disadvantages. 
  Inexpensive and easily procured models such as gelatin and meat based models are commonly used in teaching, but offer a low fidelity experience of what a trainee would expect when performing UGRA in patients. Anatomical relationships, tactile feedback, appearance of human tissues and fascial planes under ultrasound, and nerve block needle echogenicity are not realistic. In our experience, these models are useful in introducing novices to UGRA but create overconfidence in performance as they do not reflect the clinical reality. 
  The meat model, usually constructed out of turkey, beef or pork, is relatively inexpensive, easy to construct, and has more similar properties to human tissue in terms of echogenicity and texture. Hydrodissection by injections of simulated local anaesthetic can also be performed. However, meat models do not have realistic human anatomical relationships.
  Unlike traditional formalin based cadaveric dissections, fresh frozen human cadavers retain all of the in vivo anatomical relationships and currently represents the highest fidelity model for UGRA training. Nerves, fascial planes, and muscle textures are similar to live patients. Tactile feedback is retained when performing needling manoeuvres. Injection spreads patterns are similar to live patients. Limitation to access include financial cost and scarcity of centres accredited to handle fresh cadavers.  

This study will compare the effectiveness of two in vitro models commonly used to teach UGRA: pork meat model, and fresh frozen cadavers. Effectiveness is measured using objective assessment of proficiency in procedural skills before and after exposure to different in vitro models. 

RATIONALE FOR PERFORMING THE STUDY
The traditional apprenticeship model of teaching medicine has emphasised clinical exposure and supervised tutelage of procedural skills in our patients. Due to multiple factors including ethical concerns of relatively unskilled trainees performing invasive procedures on patients, reduction in caseload due to safe working hours directives, and reduction of available teaching staff, this apprenticeship model may be inappropriate. 

  In UGRA, poor needle visualisation and suboptimal sonoanatomical imaging have been identified as the two most common mistakes in novices, which may contribute to patient complications during nerve blocks. Educators are still uncertain as to the best methods of teaching UGRA, including what are the best in vitro models. 

In this study, we will compare the effectiveness of 2 commonly used in vitro  models. The models range from low fidelity (but low cost, easily accessible) to high fidelity (but high cost, not easily accessible). Each model has been used and reported in literature, but no previous study has compared each model's effectiveness in teaching procedural skills to trainees. 

The results of this study will inform us of the value of fresh frozen cadavers in UGRA teaching. We will compare the relative skills of trainees taught with different models using an objective assessment tool. If the hypothesis is confirmed, we would recommend that fresh frozen cadavers be incorporated into regular UGRA teaching. 

HYPOTHESIS
That fresh frozen human cadavers, representing a high fidelity simulator of human anatomy, is the most effective in vitro model to teach UGRA technical skills to doctors training in anaesthesia when measured against time taken, error rates, and success rates.

STUDY OBJECTIVES
Primary objective is time taken from insertion of the needle using an in-plane technique (maintaining visualisation of needle shaft and tip) to the 6 o’clock and 12 o’clock positions of the target, and injecting 0.5mls of saline at each position.

Secondary outcomes were selected based on common problems exhibited by novices in UGRA. 
1. Number of needle passes 
2. Number of errors during performance of task
3. Image quality score of best sonoanatomical image

Trial website

n/a

Trial related presentations / publications

Chuan A et al. Comparison of human cadaveric and meat-based models for teaching ultrasound-guided regional anaesthesia: a randomised controlled trial. In print, Anaesthesia 2016.

Public notes

n/a

Contacts

Principal investigator

Name

Dr Alwin Chuan

Address

Australian School of Advanced Medicine
2 Technology Place
Macquarie University
North Ryde
NSW 2109

Country

Australia

Phone

+61 407743668

Fax

[email protected]

Contact person for public queries

Name

Alwin Chuan

Address

Australian School of Advanced Medicine
2 Technology Place
Macquarie University
North Ryde
NSW 2109

Country

Australia

Phone

+61 407743668

Fax

[email protected]

Contact person for scientific queries

Name

Alwin Chuan

Address

Australian School of Advanced Medicine
2 Technology Place
Macquarie University
North Ryde
NSW 2109

Country

Australia

Phone

+61 407743668

Fax

[email protected]

No information has been provided regarding IPD availability

What supporting documents are/will be available?

No Supporting Document Provided

Results publications and other study-related documents

Documents added manually

No documents have been uploaded by study researchers.

Documents added automatically

No additional documents have been identified.

Trial Review

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