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LaryngospasmPhase 4NCT00665418

Sevoflurane and Laryngeal Reflex Responses in Pediatric Patients

A Phase 4 study testing sevoflurane in people with Laryngospasm, run by University Hospital, Basel, Switzerland.

Terminated

Stopped early. The study ended before it was planned to and will not resume.

Official record
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Trial summary

To describe laryngeal and respiratory reflex responses after controlled laryngeal stimulation in pediatric patients anesthetized with sevoflurane and to compare the evoked responses at two levels of anesthesia. Read more about this study

Who is it for?
Ages 25 to 84 months
Conditions the study is for
Laryngospasm
What is being tested?
sevoflurane
Could I receive a placebo?
No, everyone receives an active treatment
How many people
40 participants
Where
No sites listed yet
Study dates
Feb 2008to Aug 2008
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 25 to 84 months
  • All sexes
  • No healthy volunteers
  • Child

Who may be able to join

  • ASA I + II
  • Elective intervention under general anesthesia

Who cannot join

  • Reactive airway disease
  • Respiratory tract infection (previous 2 weeks)
  • Malignant hyperthermia
  • Neuromuscular disease
  • Cardiac disease

About this study

Official title: Impact of High Concentrations of Sevoflurane on Laryngeal Reflex Responses in Pediatric Patients

To describe laryngeal and respiratory reflex responses after controlled laryngeal stimulation in pediatric patients anesthetized with sevoflurane and to compare the evoked responses at two levels of anesthesia. To determine whether laryngeal and respiratory reflex responses after controlled laryngeal stimulation are completely suppressed in subjects when anesthetized with a MACEI95 (EI = endotracheal intubation) sevoflurane Hypothesis: The incidence of apnea with laryngospasm evoked by laryngeal stimulation will be reduced by 20% (from 25% to 5%) when the end-tidal concentration of sevoflurane is increased from 2.5% (MAC50) to 4.7% (MACEI95)

Read the detailed description

Induction of anesthesia inhaling sevoflurane is a very common practice in pediatric anesthesia.However, unwarranted exaggerated upper airway defensive reflexes that develop into apnea and laryngospasm with resultant hypoxemia is more common and also more severe.

Despite their obvious clinical significance, reflexes that involve the function of the upper airway are only minimally understood and information on such reflexes is scarce in anesthetized humans. Nonetheless, a model was developed by analyzing respiratory variables and endoscopic images after stimulating the laryngeal mucosa with a small amount of distilled water. Clinical experience suggests that laryngeal reflexes occur more frequently under light levels of anesthesia. However, in contrast to other inhalational agents such as halothan, available data for sevoflurane suggest that an inverse correlation of laryngeal responsiveness to depth of hypnosis or end-tidal concentrations of sevoflurane (in adults and children) is less obvious. However, in all previous studies assessing laryngeal reflex responses under sevoflurane only low concentrations of sevoflurane (range of 1.0 - 2.5 Vol%) were examined. This is an important limitation because in clinical practice higher concentrations of sevoflurane are used, especially during manipulation of the airway, while the risk of airway irritation is high. Thus, the proposed study aims to explore the question whether the occurrence of laryngospasm can be reliably suppressed when high concentrations of sevoflurane are used.

Based on results of experiments assessing conditions that facilitate tracheal intubation, it is clear, that increasing the end-tidal concentration of volatile agents obtunds airway reflexes. Regarding intubation conditions, the concept of MACEI 50% or 95% describes the minimum alveolar concentration (MAC) of a volatile anesthetic needed by 50 or 95% of the patients, respectively, to prevent all movement during and immediately after tracheal intubation. The proposed study aims to assess respiratory reflex responses at these levels of anesthesia by analyzing the respiratory variables and endoscopic images. The incidences of well-defined airway reflexes (cough reflex, spasmodic panting, expiration reflex, and apnea with laryngospasm, central apnea) will be examined. Apnea with laryngospasm will be of primary interest in our study and digital video analysis of the glottic opening will allow for a detailed analysis of laryngeal performance.

Conditions
Laryngospasm
Being tested
sevoflurane
Keywords
Anesthesia, children, Larynx
Medical subject headings
Laryngismus, Laryngeal Diseases

What participants receive

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

  • sevofluraneDrug

    Also called Ultane

    sevoflurane 2.5% versus 4.7% (inhaled concentration) 10min each

Study groups in NCT00665418
Study groupRoleWhat they receive
1ExperimentalNot described
Receives: Drug: sevoflurane

What is being measured

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

  1. Occurence of laryngospasm (defined as complete closure of the vocal or false cords with apnea lasting >10sec) after laryngeal stimulation

    Measured: 5min

Timeline

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

  1. First posted23 Apr 2008 (estimated)
  2. Study startFeb 2008
  3. Primary completionAug 2008
  4. Study completionAug 2008

Why it stopped: Recruitment finished earlier, because all 40 patients enrolled

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
Prevention
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrolment
40 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT00665418
Sponsor's protocol ID
UNIBAS_UKBB_ANE_LR4
Other IDs
SNF_3200B0-109322
Status last verified
Mar 2009
First submitted
23 Jan 2008
Last updated
12 Mar 2009
Results posted
No
Data monitoring committee
No

Publications

  • Oberer C, von Ungern-Sternberg BS, Frei FJ, Erb TO. Respiratory reflex responses of the larynx differ between sevoflurane and propofol in pediatric patients. Anesthesiology. 2005 Dec;103(6):1142-8. doi: 10.1097/00000542-200512000-00007.

    PubMed 16306725

Questions about this trial

What is this clinical trial studying?

A Phase 4 study testing sevoflurane in people with Laryngospasm, run by University Hospital, Basel, Switzerland.

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 5 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 12 Mar 2009. Status can change between updates, so confirm with the study contact before making plans.

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 was stopped early (reason given: Recruitment finished earlier, because all 40 patients enrolled). 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?

Occurence of laryngospasm (defined as complete closure of the vocal or false cords with apnea lasting >10sec) after laryngeal stimulation (time frame: 5min). 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 NCT00665418, 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 12 Mar 2009.

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