HypotensionNCT00884026
Can Augmentation Index (AIx) be Used to Predict Hypotension After Spinal Anesthesia?
A study testing AIx measurement with a Sphygmacor TM in people with Hypotension and Cesarean Delivery, run by University of British Columbia at 1 site in Canada.
Trial summary
A fall in blood pressure (hypotension) occurs in one third of spinal anesthetics administered to pregnant patients undergoing cesarean delivery. However, predicting which patients will experience hypotension following spinal anesthesia has proven difficult. Read more about this study
- Who is it for?
- Ages 19 to 45 years, women onlyHealthy volunteers can take part
- Conditions the study is for
- Hypotension, Cesarean Delivery
- What is being tested?
- AIx measurement with a Sphygmacor TM
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 56 participants
- Where
- 1 siteCanada
- Study dates
- Mar 2009to Mar 2010
- Phase
- Interventional
- 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 19 to 45 years
- Women only
- Healthy volunteers accepted
- Adult
Who may be able to join
- All women undergoing elective or urgent cesarean delivery under spinal anesthesia
- Singleton Pregnancy
- Greater than 37 weeks gestation
- Healthy subjects with ASA 1 \& 2 classification of health
- Potential subjects need to be able to read and understand English unless independent (non-partner) translator available
Who cannot join
- ASA 3 or above
- Emergency cesarean delivery for fetal heart rate abnormalities
- Cesarean delivery under general, epidural, or combined spinal epidural anesthesia
- Maternal age <19 years
- Maternal infection
- Mothers with vascular disease - including hypertension/pre-eclampsia
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- Mothers with Diabetes Mellitus
- Polyhdramnios
- Multiple Pregnancy
- Height < 150cm or > 180cm
- BMI > 40
Trial locations and contacts
1 site in 1 country.
Canada1 site
BC Women's Hospital Dept of Anesthesia
Vancouver, British Columbia
About this study
Official title: Pulse Wave Analysis and Augmentation Index Changes Associated With Neuraxial Anesthesia in the Parturient
A fall in blood pressure (hypotension) occurs in one third of spinal anesthetics administered to pregnant patients undergoing cesarean delivery. However, predicting which patients will experience hypotension following spinal anesthesia has proven difficult. Pulse wave analysis is a repeatable and reproducible method for investigation of cardiovascular function. A device called a SphygmacorTM can be used to measure pulse. The pulse measurement is called the Augmentation Index (AIx). AIx has been useful in detecting risks associated with blood pressure changes after complex surgery in patients with heart and blood vessel disease. In this study the investigators wish to see if it is possible to predict if a subject will experience hypotension based on her AIx measurement preoperatively.
Read the detailed description
At BC Women's Hospital (BCWH), anesthesiologists give spinal anesthesia for most elective cesarean deliveries. When the spinal medication is given, blood vessels expand in reaction to the spinal medication causing blood pressure to fall. If a patient experiences this common reaction, the anesthesiologist would administer some medications to restore blood pressure to normal. They do this to protect the blood supply to the placenta and to the baby.
It is not known why this happens in some people and not in others. The way blood circulates through the body can provide information about changes occurring in the body. Pulse measurements are a simple way of providing physicians with important clinical information about patient health.
A device called a SphygmacorTM can be used to measure a pulse. The pulse measurement is called the Augmentation Index (AIx). AIx has been useful in detecting risks associated with blood pressure changes after complex surgery in patients with heart and blood vessel disease. In our study we wish to see if AIx can predict a normal patient's risk of hypotension after spinal anesthesia. If a trend between AIx and the onset of hypotension after spinal anesthesia can be found, anesthesiologists can more effectively prevent and treat hypotension by being able to predict whether it will occur.
Consenting subjects will have their blood pressure and AIx measurement taken prior to surgery.
Surgery will commence as per usual practice at BCWH. If hypotension occurs after the spinal anesthesia, anesthesiologist will treat as per usual practice.
Following recruitment and data collection on the first 30 subjects we will review their anesthetic records to assess whether they became hypotensive or not (systolic BP > 20% from baseline). This will give us two groups. Group 1 will be those subjects who developed hypotension, and Group 2 will be those subjects who did not develop hypotension. We will then look at the preoperative measured AIx to determine whether there is a baseline difference between the two groups. A threshold value of the AIx with the best sensitivity and specificity for prediction of hypotension will then be determined.
The second part of the study will then use the threshold AIx value found from the subjects who developed hypotension from the first 30 subjects to prospectively predict hypotension after spinal anesthesia in another 60 subjects.
- Conditions
- Hypotension, Cesarean Delivery
- Being tested
- AIx measurement with a Sphygmacor TM
- Keywords
- Cesarean delivery, hypotension, Augmentation Index, Pulse Wave analysis, spinal anesthesia, Hypotension following spinal anesthesia for cesarean delivery
- Medical subject headings
- Hypotension
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
AIx measurement with a Sphygmacor TMDevice
All subjects will have their AIx measured prior to surgery. After 30 subjects are recruited, they will be split into 2 groups. Group 1 will be those subjects who developed hypotension, and Group 2 will be those subjects who did not develop hypotension. We will then look at the preoperative measured AIx to determine whether there is a baseline difference between the two groups. A threshold value of the AIx with the best sensitivity and specificity for prediction of hypotension will then be determined.
AIx measurement with a Sphygmacor TMDevice
The second part of the study will then use the threshold AIx value found from the subjects who developed hypotension from the first 30 subjects to prospectively predict hypotension after spinal anesthesia in another 60 subjects
| Study group | Role | What they receive |
|---|---|---|
| 1 | Active comparator | Subjects that experience hypotension after spinal anesthesia. Receives: Device: AIx measurement with a Sphygmacor TM |
| 2 | Active comparator | Subjects that do not experience hypotension after spinal anesthesia. Receives: Device: AIx measurement with a Sphygmacor TM |
What is being measured
The primary outcome is the main question the study is designed to answer.
Occurrence of hypotension following spinal anesthesia. Defined as systolic BP > 20% from baseline.
Measured: 1 week
Secondary outcomes (1)
Augmentation Index as measured by the SphygmacorTM preoperatively; Bradycardia requiring pharmacological treatment; Ephedrine requirement; Phenylephrine requirement; Block Height; Nausea/vomiting
Measured: 1 week
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Apr 2009 (estimated)
- Study startMar 2009
- Primary completionMar 2010
- Study completionMar 2010
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HypotensionStudies of the same condition, open and under way.
- More trials run by University of British ColumbiaThe 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 56 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of British Columbia
- Sponsor type
- University, hospital or other
- Collaborators
- Children's & Women's Health Centre of British Columbia
- Responsible party
- Sponsor
- Investigators
- Vit Gunka, MD, FRCPC, Principal investigator, University of British ColumbiaJames Shannon, FCARSCI MSc, Study director, University of British ColumbiaJoanne Douglas, MD, FRCPC, Study director, University of British ColumbiaJessica Tyler, BSc, Study director, University of British Columbia
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00884026
- Sponsor's protocol ID
- H08-03019
- Status last verified
- Jan 2013
- First submitted
- 3 Apr 2009
- Last updated
- 23 Jan 2013
- Results posted
- No
- Data monitoring committee
- No
Study at a glance
From the registry record, last updated by the sponsor on 23 Jan 2013. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Pulse Wave Analysis and Augmentation Index Changes Associated With Neuraxial Anesthesia in the Parturient
- ClinicalTrials.gov ID
- NCT00884026
- Acronym / sponsor ID
- H08-03019
- Conditions
- Hypotension, Cesarean Delivery
- Keywords
- Cesarean delivery, hypotension, Augmentation Index, Pulse Wave analysis, spinal anesthesia, Hypotension following spinal anesthesia for cesarean delivery
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 56 participants (actual)
- Lead sponsor
- University of British ColumbiaUniversity, hospital or other
- Collaborators
- Children's & Women's Health Centre of British Columbia
- Study start
- Mar 2009
- Primary completion
- Mar 2010 (actual)
- Study completion
- Mar 2010 (actual)
- First posted
- 20 Apr 2009 (estimated)
- 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.
A fall in blood pressure (hypotension) occurs in one third of spinal anesthetics administered to pregnant patients undergoing cesarean delivery. However, predicting which patients will experience hypotension following spinal anesthesia has proven difficult. Pulse wave analysis is a repeatable and reproducible method for investigation of cardiovascular function. A device called a SphygmacorTM can be used to measure pulse. The pulse measurement is called the Augmentation Index (AIx). AIx has been useful in detecting risks associated with blood pressure changes after complex surgery in patients with heart and blood vessel disease. In this study the investigators wish to see if it is possible to predict if a subject will experience hypotension based on her AIx measurement preoperatively.
Detailed description
At BC Women's Hospital (BCWH), anesthesiologists give spinal anesthesia for most elective cesarean deliveries. When the spinal medication is given, blood vessels expand in reaction to the spinal medication causing blood pressure to fall. If a patient experiences this common reaction, the anesthesiologist would administer some medications to restore blood pressure to normal. They do this to protect the blood supply to the placenta and to the baby.
It is not known why this happens in some people and not in others. The way blood circulates through the body can provide information about changes occurring in the body. Pulse measurements are a simple way of providing physicians with important clinical information about patient health.
A device called a SphygmacorTM can be used to measure a pulse. The pulse measurement is called the Augmentation Index (AIx). AIx has been useful in detecting risks associated with blood pressure changes after complex surgery in patients with heart and blood vessel disease. In our study we wish to see if AIx can predict a normal patient's risk of hypotension after spinal anesthesia. If a trend between AIx and the onset of hypotension after spinal anesthesia can be found, anesthesiologists can more effectively prevent and treat hypotension by being able to predict whether it will occur.
Consenting subjects will have their blood pressure and AIx measurement taken prior to surgery.
Surgery will commence as per usual practice at BCWH. If hypotension occurs after the spinal anesthesia, anesthesiologist will treat as per usual practice.
Following recruitment and data collection on the first 30 subjects we will review their anesthetic records to assess whether they became hypotensive or not (systolic BP > 20% from baseline). This will give us two groups. Group 1 will be those subjects who developed hypotension, and Group 2 will be those subjects who did not develop hypotension. We will then look at the preoperative measured AIx to determine whether there is a baseline difference between the two groups. A threshold value of the AIx with the best sensitivity and specificity for prediction of hypotension will then be determined.
The second part of the study will then use the threshold AIx value found from the subjects who developed hypotension from the first 30 subjects to prospectively predict hypotension after spinal anesthesia in another 60 subjects.
Study design
- Primary purpose
- Prevention
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| 1 | Active comparator | Device: AIx measurement with a Sphygmacor TMSubjects that experience hypotension after spinal anesthesia. |
| 2 | Active comparator | Device: AIx measurement with a Sphygmacor TMSubjects that do not experience hypotension after spinal anesthesia. |
Who may qualify
- Ages
- 19 to 45 years
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- All women undergoing elective or urgent cesarean delivery under spinal anesthesia
- Singleton Pregnancy
- Greater than 37 weeks gestation
- Healthy subjects with ASA 1 \& 2 classification of health
- Potential subjects need to be able to read and understand English unless independent (non-partner) translator available
Key exclusion criteria (11 listed)
- ASA 3 or above
- Emergency cesarean delivery for fetal heart rate abnormalities
- Cesarean delivery under general, epidural, or combined spinal epidural anesthesia
- Maternal age <19 years
- Maternal infection
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 |
|---|---|---|
| AIx measurement with a Sphygmacor TMAll subjects will have their AIx measured prior to surgery. After 30 subjects are recruited, they will be split into 2 groups. Group 1 will be those subjects who developed hypotension, and Group 2 will be those subjects who did not develop hypotension. We will then look at the preoperative measured AIx to determine whether there is a baseline difference between the two groups. A threshold value of the AIx with the best sensitivity and specificity for prediction of hypotension will then be determined. | Device | 1 |
| AIx measurement with a Sphygmacor TMThe second part of the study will then use the threshold AIx value found from the subjects who developed hypotension from the first 30 subjects to prospectively predict hypotension after spinal anesthesia in another 60 subjects | Device | 2 |
Primary outcome
Occurrence of hypotension following spinal anesthesia. Defined as systolic BP > 20% from baseline.
Time frame: 1 week
1 secondary outcome
Augmentation Index as measured by the SphygmacorTM preoperatively; Bradycardia requiring pharmacological treatment; Ephedrine requirement; Phenylephrine requirement; Block Height; Nausea/vomiting
Time frame: 1 week
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 Jan 2013.
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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.
Vit Gunka, MD, FRCPC principal investigator
University of British Columbia
James Shannon, FCARSCI MSc study director
University of British Columbia
Joanne Douglas, MD, FRCPC study director
University of British Columbia
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing AIx measurement with a Sphygmacor TM in people with Hypotension and Cesarean Delivery, run by University of British Columbia 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 5 inclusion and 11 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: finished, as of the sponsor's last update on 23 Jan 2013. 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 is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
Occurrence of hypotension following spinal anesthesia. Defined as systolic BP > 20% from baseline. (time frame: 1 week). 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 23 Jan 2013.