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Sevoflurane AnesthesiaPhase 4NCT02054143

The Effect of Sevoflurane on Cerebral CO2 Sensitivity and Systemic Arteries

A Phase 4 study testing Partial pressure of CO2 at the end of an exhaled breath and Sevoflurane in people with Sevoflurane Anesthesia, run by University of Debrecen at 1 site in Hungary.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

Purpose: The purpose of this study is to examine the effect of different carbon-dioxide concentrations on cerebral CO2 sensitivity and the resistance and stiffness of systemic arteries during anesthesia with sevoflurane. Read more about this study

Who is it for?
Ages 18 to 60 years
Conditions the study is for
Sevoflurane Anesthesia
What is being tested?
Partial pressure of CO2 at the end of an exhaled breath and Sevoflurane
Type of treatment
Surgery or procedure
Could I receive a placebo?
No, everyone receives an active treatment
How many people
24 participants
Where
1 siteHungary
Study dates
Nov 2012to Apr 2013
Phase
Phase 4
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 18 to 60 years
  • All sexes
  • No healthy volunteers
  • Adult

Who may be able to join

  • Above the age 18
  • American Society of Anesthesiologists (ASA) physical classification I. or II.
  • Patients undergoing elective varicotomy or inguinal hernioplasty in general anesthesia

Who cannot join

  • Patients with cerebral, cardiac or systemic vascular disorders (hypertension, diabetes)
  • Patients receiving medication that affects the blood vessels (antihypertensive, antidiabetic, antiarrhythmic medications)

Trial locations and contacts

1 site in 1 country.

Hungary1 site
  • University of Debrecen Medical and Health Science Center Department of Anesthesiology and Intensive Care

    Debrecen, 4032

Other trials in Hungary

About this study

Official title: The Effect of Sevoflurane on Cerebral Vasoreactivity Ans Systemic Arteries

Purpose:

  • The purpose of this study is to examine the effect of different carbon-dioxide concentrations on cerebral CO2 sensitivity and the resistance and stiffness of systemic arteries during anesthesia with sevoflurane. Sevoflurane is a widely and commonly used inhalational anaesthetic, that is mainly used for the maintenance of general anesthesia.
  • Changes in the velocity of cerebral blood flow and arterial stiffness due to the different exhaled carbon-dioxide concentrations will allow us to conclude how sevoflurane affects these parameters during the course of the narcosis.
Read more

Instruments:

  • An ultrasound device called transcranial doppler (TCD) is used to measure the velocity of blood flow within a main artery located inside the skull.
  • A tonometry device named SphygmoCor is used to assess the pressure wave proceeding in the radial artery, from which the stiffness of the systemic vessels can be concluded.

Measurements:

  • Examinations with the ultrasound and tonometry devices are carried out once before the operation, three times during the intervention, with different exhaled CO2 values and once after the operation is completed.

Hypothesis:

  • Sevoflurane alters cerebral carbon-dioxide sensitivity and the stiffness of systemic arteries.
Read the detailed description

Study protocol:

  • The study is conducted in four stages: in the first stage, measurements are performed preoperatively in awake patients. Patients are placed in supine position and mean arterial blood pressure (MAP), heart rate, oxygen saturation are measured. The transcranial doppler (TCD) probe is fixed in place by applying a headband to maintain a constant angle of insonation. Mean blood flow velocity (MBFV) and pulsatility index (PI) in the middle cerebral artery (MCA) are obtained. MCA is insonated through the right temporal window by using pulsed 2 megahertz TCD ultrasound probe. Identification of the MCA is confirmed by using standard criteria, at a depth of 45-55 mm. Cerebral CO2 vasoreactivity is calculated as the percentage change in MBFV or PI for mmHg change in end-tidal CO2 (ETCO2).

SphygmoCor is placed on the left radial artery to obtain data about the central aortic blood pressure, augmentation pressure (AP) and augmentation index normalised to a 75 beat per minute heart rate (Alx75). From the derived aortic pulse, calculations can be made, using the area under the systolic and diastolic part of the curve, to determine the heart's ratio of oxygen supply and demand, it is called the subendocardial viability ratio (SEVR).

As part of the premedication each patient receives 7.5 mg midazolam. Anaesthesia is induced using 2 mcg/kg fentanyl followed by 2 mg/kg propofol. Afterwards 0.6mg/kg rocuronium is given for muscle paralysis and subsequently patients were intubated with a suitable intratracheal tube.

After induction of anaesthesia, the patients are placed on a mechanical ventilation system, using a volume-controlled setting with an air and oxygen mixture set to 0.4 fraction of inspired oxygen (FiO2) , the fresh gas flow rate to 2 l/min and sevoflurane is adjusted to reach a constant 1minimal alveolar concentration (MAC) during examination. Anesthesia is maintained with sevoflurane and on demand fentanyl boluses.

Differences in the depth of anesthesia could influence cerebral activity, thereby cerebral metabolism and blood flow. Bispectral index is placed onto every patient in order to assure constant depth of anaesthesia during the intervention.

The second series of TCD and SphygmoCor measurements are performed 20 minutes after the respiratory rate is set to maintain end-tidal CO2 at 40 mmHg in order to allow sufficient time for equilibrium to be reached and the effect of drugs used for the induction of anesthesia to be terminated. Subsequently the examinations are repeated twice again at 35 and 30 mmHg ETCO2. The measurements were carried out 5-5 minutes after adjusting the minute ventilation to reach target ETCO2 values.

Statistical methods:

  • Comparisons between the preoperative and three intraoperative stages of the study are made using repeated measures ANOVA with the Bonferroni post hoc correction. The relationship between MBFV, PI and ETCO2 is assessed using linear regression, while the connection between SEVR, pulse and Alx75 is calculated with bivariate correlation.
Being tested
Partial pressure of CO2 at the end of an exhaled breath, Sevoflurane
Keywords
sevoflurane, cerebral vasoreactivity, arterial stiffness, Transcranial Doppler, SphygmoCor

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Partial pressure of CO2 at the end of an exhaled breathProcedure or surgery

    Also called EtCO2

    Three previously defined EtCO2 levels (partial pressure of CO2 at the end of an exhaled breath) were adjusted during anesthesia.

  • SevofluraneDrug

    Also called Sevorane

    Sevoflurane was administered to all patients at 1 minimal alveolar concentration (MAC) during the whole operation.

Study groups in NCT02054143
Study groupRoleWhat they receive
SevofluraneExperimentalSevoflurane was administered to all patients at 1 minimal alveolar concentration (MAC) after the intubation occured until the patient was extubated.
Receives: Procedure: Partial pressure of CO2 at the end of an exhaled breath; Drug: Sevoflurane

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Blood flow velocity in the middle cerebral artery

    Systolic, diastolic and mean blood flow velocities are measured with transcranial doppler device.

    Measured: Changes from baseline in blood flow velocity at the 15th, 20th and 25th minutes of the operation

Secondary outcomes (2)
  1. Arterial wall stiffness of the radial artery

    The stiffness of the radial artery is assessed. Stiffness rate is concluded from the augmentation pressure and augmentation index, from which both values are provided by the tonometry device.

    Measured: Changes from baseline in arterial stiffness at the 15th, 20th and 25th minutes of the operation

  2. Changes in the central systolic and diastolic blood pressure

    CEntral blood pressure values are measured by means of tonometry device on the radial artery.

    Measured: Changes from baseline in central blood pressure at the 15th, 20th and 25th minutes of the operation

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted4 Feb 2014 (estimated)
  2. Study startNov 2012
  3. Primary completionApr 2013
  4. Study completionApr 2013

Resources

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 4
Primary purpose
Basic science
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrolment
24 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT02054143
Sponsor's protocol ID
17637-1/2012/EKU
Other IDs
DEOEC RKEB/IKEB:3584-2012
Status last verified
Feb 2014
First submitted
31 Jan 2014
Last updated
4 Feb 2014
Results posted
No
Data monitoring committee
Yes

Publications

  • Juhasz M, Molnar L, Fulesdi B, Vegh T, Pall D, Molnar C. Effect of sevoflurane on systemic and cerebral circulation, cerebral autoregulation and CO2 reactivity. BMC Anesthesiol. 2019 Jun 19;19(1):109. doi: 10.1186/s12871-019-0784-9.

    PubMed 31215448

Questions about this trial

What is this clinical trial studying?

A Phase 4 study testing Partial pressure of CO2 at the end of an exhaled breath and Sevoflurane in people with Sevoflurane Anesthesia, run by University of Debrecen at 1 site in Hungary.

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 3 inclusion and 2 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 4 Feb 2014. 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 Hungary. 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.

What does this phase mean?

Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

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?

Blood flow velocity in the middle cerebral artery (time frame: Changes from baseline in blood flow velocity at the 15th, 20th and 25th minutes of the operation). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT02054143, which also lists 1 linked publication.

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 4 Feb 2014.

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