Regional AnesthesiaNCT03377764
Spinal Anesthesia in Patients With Poorly-palpable Surface Landmarks
An observational study of Regional Anesthesia, run by University Health Network, Toronto at 1 site in Canada.
Trial summary
Anesthesia trainees can perform spinal anesthesia in patients who have poorly-palpable surface landmarks with fewer needle passes using an ultrasound-guided technique compared to the conventional surface landmark-guided technique. Read more about this study
- Who is it for?
- Any age
- Conditions the study is for
- Regional Anesthesia
- What is being tested?
- Neuroaxial block using Ultrasound Guidance
- Type of treatment
- Surgery or procedure
- How many people
- 48 participants
- Where
- 1 siteCanada
- Study dates
- Aug 2011to May 2014
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages Any age
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Study population: We will recruit patients presenting for elective total hip or knee replacement under spinal anesthesia, who have poorly palpable or impalpable spinous processes and a body mass index (BMI) ≥ 35 kgm-2. Exclusion criteria include inability or refusal to provide informed consent, bleeding diathesis, allergy to local anesthetics, or any other contra-indication to spinal anesthesia. Criteria for withdrawal after enrolment will include cancellation of surgery, unavailability of personnel with the requisite experience to perform the ultrasound-guided technique, and patient refusal to participate or continue with the study at any point up to completion of the US scan.
Who may be able to join
- Patients presenting for elective total hip or knee replacement under spinal anesthesia who have poorly palpable or impalpable spinous processes
- BMI ≥ 35 kgm-2
Who cannot join
- Inability or refusal to provide informed consent,
- Bleeding diathesis,
- Allergy to local anesthetics
- Contra-indication to spinal anesthesia
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Can Anesthesia Trainees Effectively Use Ultrasound Imaging to Facilitate the Performance of Spinal Anesthesia in Patients With Poorly-palpable Surface Landmarks?
Anesthesia trainees can perform spinal anesthesia in patients who have poorly-palpable surface landmarks with fewer needle passes using an ultrasound-guided technique compared to the conventional surface landmark-guided technique.
Read the detailed description
Neuraxial blockade has traditionally been accomplished using a surface landmark-guided technique, in which the approximate location of the neuraxial midline, lumbar interspinous and interlaminar spaces are determined based on palpation of the intercristal line and the tips of the spinous processes. It is not surprising, therefore, that the technical difficulty of neuraxial blockade (usually measured in terms of the number of needle passes required for success) correlates with the quality of palpable surface landmarks.
Reducing the technical difficulty of neuraxial blockade is desirable as multiple needle insertion attempts may increase the risk of complications such as post-dural puncture headache, paresthesiae, and epidural hematoma. Ultrasound (US) imaging of the spine can help in this regard by more precisely identifying landmarks, determining the intervertebral level, and measuring the depth to the epidural space. It has been shown to facilitate the performance of neuraxial block in the obstetric population, and our group has also demonstrated similar benefits in the older non-obstetric population. In a feasibility study of US-guided spinal anesthesia for total joint replacement surgery, achieved successful spinal anesthesia with a single needle insertion attempt in 84% of these patients, despite the fact that nearly half of them had poorly palpable surface landmarks.This compares well with large prospective cohort studies which report successful neuraxial blockade on the first needle insertion attempt in 61-64% of all patients. Investigators recently completed a randomized controlled trial in which 120 patients with difficult anatomical landmarks (defined as poorly palpable surface landmarks and a BMI>35 kgm-2, significant spinal deformity, or spinal surgery resulting in distortion or absence of surface landmarks) received spinal anesthesia performed by experienced anesthesiologists using either a conventional surface landmark-guided technique or an US-guided technique. There was a two-fold difference between the US-guided group and the control group in the first-attempt success rate (62% vs 32%, P<0.001), and the median number of needle passes required for success (6 vs 13, P=0.003).
The main limitation of all clinical studies conducted to date on US-guided neuraxial block is that ultrasound imaging was performed solely by experienced operators; although in two studies the neuraxial block itself (but not the ultrasound scan) was performed by trainees.
Investigators believe that the benefits of the US-guided technique can be realized when it is performed in its entirety by novices, e.g. anesthesia trainees. Investigators therefore designed this study to establish if novices are able to use the US-guided technique to facilitate the performance of spinal anesthesia in obese patients with poorly-palpable landmarks.
- Conditions
- Regional Anesthesia
- Being tested
- Landmark Technique Control group, Neuroaxial block using Ultrasound Guidance
- Keywords
- Spinal Anesthetic,, Ultrasound guided Neuroaxial block,, Anesthesia Trainees
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Landmark Technique Control groupProcedure or surgery
Spinal Anesthetic
Neuroaxial block using Ultrasound GuidanceProcedure or surgery
Ultrasound guided Spinal Anesthetic
| Study group | Role | What they receive |
|---|---|---|
| Landmark Technique | Control group Receives: Procedure: Landmark Technique Control group | |
| Ultrasound guided technique | Neuroaxial block using Ultrasound guidance Receives: Procedure: Neuroaxial block using Ultrasound Guidance |
What is being measured
The primary outcome is the main question the study is designed to answer.
The rate of successful dural puncture on the first needle insertion attempt.
Insertion attempts are defined as complete withdrawal of the needle or introducer from the skin followed by re-insertion, and are distinguished from redirection attempts, which are defined as changes in needle trajectory that do not involve complete withdrawal of the needle from the skin. 1,2.14,15 This will be assessed by two blinded observers from an anonymized video recording of the operator's hands as they perform the spinal anesthetic.
Measured: 2012-2013
Secondary outcomes (3)
The total number of needle passes required for dural puncture.
Needle passes are defined as any forward advancement of the needle, including the first insertion and any subsequent insertion and redirection attempts. This will be assessed by two blinded observers from an anonymized video recording of the operator's hands as they perform the spinal anesthetic.
Measured: 2012-2013
Block performance time
Block performance time, defined as the sum of the following:
- Time taken to establish landmarks. In the US-guided technique, this is defined as the time between first placement of the ultrasound probe on the patient and completion of the last skin marking. In the surface landmark-guided technique, this is defined as the time between first placement of the operator's hands on the patient and completion of the last skin marking.
Measured: 2012-2013
Time taken to perform spinal anesthetic
Time taken to perform spinal anesthetic. This is defined as the period between insertion of the needle used for skin infiltration, and withdrawal of the spinal needle following injection of the
Measured: 2012-2013
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Dec 2017
- Study startAug 2011
- Primary completionMay 2014
- Study completionMay 2014
Why it stopped: The interim data analysis shows no significant difference between groups
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Regional AnesthesiaStudies of the same condition, open and under way.
- More trials run by University Health Network, TorontoThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case-control
- Time perspective
- Prospective
- Enrolment
- 48 participants (actual)
Sponsor and investigators
- Lead sponsor
- University Health Network, Toronto
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03377764
- Sponsor's protocol ID
- 11-0054-A
- Status last verified
- May 2011
- First submitted
- 31 Oct 2016
- Last updated
- 19 Dec 2017
- Results posted
- No
- Data monitoring committee
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 19 Dec 2017. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Can Anesthesia Trainees Effectively Use Ultrasound Imaging to Facilitate the Performance of Spinal Anesthesia in Patients With Poorly-palpable Surface Landmarks?
- ClinicalTrials.gov ID
- NCT03377764
- Acronym / sponsor ID
- 11-0054-A
- Conditions
- Regional Anesthesia
- Keywords
- Spinal Anesthetic,, Ultrasound guided Neuroaxial block,, Anesthesia Trainees
- Study type
- Observational
- Recruitment status
- TerminatedReason stopped: The interim data analysis shows no significant difference between groups
- Enrolment
- 48 participants (actual)
- Lead sponsor
- University Health Network, TorontoUniversity, hospital or other
- Study start
- Aug 2011 (actual)
- Primary completion
- May 2014 (actual)
- Study completion
- May 2014 (actual)
- First posted
- 19 Dec 2017 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Anesthesia trainees can perform spinal anesthesia in patients who have poorly-palpable surface landmarks with fewer needle passes using an ultrasound-guided technique compared to the conventional surface landmark-guided technique.
Detailed description
Neuraxial blockade has traditionally been accomplished using a surface landmark-guided technique, in which the approximate location of the neuraxial midline, lumbar interspinous and interlaminar spaces are determined based on palpation of the intercristal line and the tips of the spinous processes. It is not surprising, therefore, that the technical difficulty of neuraxial blockade (usually measured in terms of the number of needle passes required for success) correlates with the quality of palpable surface landmarks.
Reducing the technical difficulty of neuraxial blockade is desirable as multiple needle insertion attempts may increase the risk of complications such as post-dural puncture headache, paresthesiae, and epidural hematoma. Ultrasound (US) imaging of the spine can help in this regard by more precisely identifying landmarks, determining the intervertebral level, and measuring the depth to the epidural space. It has been shown to facilitate the performance of neuraxial block in the obstetric population, and our group has also demonstrated similar benefits in the older non-obstetric population. In a feasibility study of US-guided spinal anesthesia for total joint replacement surgery, achieved successful spinal anesthesia with a single needle insertion attempt in 84% of these patients, despite the fact that nearly half of them had poorly palpable surface landmarks.This compares well with large prospective cohort studies which report successful neuraxial blockade on the first needle insertion attempt in 61-64% of all patients. Investigators recently completed a randomized controlled trial in which 120 patients with difficult anatomical landmarks (defined as poorly palpable surface landmarks and a BMI>35 kgm-2, significant spinal deformity, or spinal surgery resulting in distortion or absence of surface landmarks) received spinal anesthesia performed by experienced anesthesiologists using either a conventional surface landmark-guided technique or an US-guided technique. There was a two-fold difference between the US-guided group and the control group in the first-attempt success rate (62% vs 32%, P<0.001), and the median number of needle passes required for success (6 vs 13, P=0.003).
The main limitation of all clinical studies conducted to date on US-guided neuraxial block is that ultrasound imaging was performed solely by experienced operators; although in two studies the neuraxial block itself (but not the ultrasound scan) was performed by trainees.
Investigators believe that the benefits of the US-guided technique can be realized when it is performed in its entirety by novices, e.g. anesthesia trainees. Investigators therefore designed this study to establish if novices are able to use the US-guided technique to facilitate the performance of spinal anesthesia in obese patients with poorly-palpable landmarks.
Study design
- Observational model
- Case-control
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Landmark Technique | – | Procedure: Landmark Technique Control groupControl group |
| Ultrasound guided technique | – | Procedure: Neuroaxial block using Ultrasound GuidanceNeuroaxial block using Ultrasound guidance |
Who may qualify
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
- Study population
- We will recruit patients presenting for elective total hip or knee replacement under spinal anesthesia, who have poorly palpable or impalpable spinous processes and a body mass index (BMI) ≥ 35 kgm-2. Exclusion criteria include inability or refusal to provide informed consent, bleeding diathesis, allergy to local anesthetics, or any other contra-indication to spinal anesthesia. Criteria for withdrawal after enrolment will include cancellation of surgery, unavailability of personnel with the requisite experience to perform the ultrasound-guided technique, and patient refusal to participate or continue with the study at any point up to completion of the US scan.
Key inclusion criteria (2 listed)
- Patients presenting for elective total hip or knee replacement under spinal anesthesia who have poorly palpable or impalpable spinous processes
- BMI ≥ 35 kgm-2
Key exclusion criteria (4 listed)
- Inability or refusal to provide informed consent,
- Bleeding diathesis,
- Allergy to local anesthetics
- Contra-indication to spinal anesthesia
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Landmark Technique Control groupSpinal Anesthetic | Procedure or surgery | Landmark Technique |
| Neuroaxial block using Ultrasound GuidanceUltrasound guided Spinal Anesthetic | Procedure or surgery | Ultrasound guided technique |
Primary outcome
The rate of successful dural puncture on the first needle insertion attempt.
Time frame: 2012-2013
Insertion attempts are defined as complete withdrawal of the needle or introducer from the skin followed by re-insertion, and are distinguished from redirection attempts, which are defined as changes in needle trajectory that do not involve complete withdrawal of the needle from the skin. 1,2.14,15 This will be assessed by two blinded observers from an anonymized video recording of the operator's hands as they perform the spinal anesthetic.
3 secondary outcomes
The total number of needle passes required for dural puncture.
Time frame: 2012-2013
Block performance time
Time frame: 2012-2013
Time taken to perform spinal anesthetic
Time frame: 2012-2013
Results and safety
The study was stopped early (reason given: The interim data analysis shows no significant difference between groups). Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 19 Dec 2017.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Regional Anesthesia, run by University Health Network, Toronto at 1 site in Canada.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: stopped early, as of the sponsor's last update on 19 Dec 2017. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study was stopped early (reason given: The interim data analysis shows no significant difference between groups). Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
The rate of successful dural puncture on the first needle insertion attempt. (time frame: 2012-2013). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 19 Dec 2017; AzTrials last refreshed its copy on 31 Oct 2026.