<clinical_study>
  <!-- This xml conforms to an XML Schema at:
    https://clinicaltrials.gov/ct2/html/images/info/public.xsd -->
  <required_header>
    <download_date>ClinicalTrials.gov processed this data on September 20, 2023</download_date>
    <link_text>Link to the current ClinicalTrials.gov record.</link_text>
    <url>https://clinicaltrials.gov/ct2/show/NCT02981511</url>
  </required_header>
  <id_info>
    <org_study_id>RHMCRI0333</org_study_id>
    <nct_id>NCT02981511</nct_id>
  </id_info>
  <brief_title>Optiflow Preoxygenation</brief_title>
  <official_title>Assessing the Potential Use of Optiflow as a Preoxygenation Method Prior to Anaesthesia.</official_title>
  <sponsors>
    <lead_sponsor>
      <agency>University Hospital Southampton NHS Foundation Trust</agency>
      <agency_class>Other</agency_class>
    </lead_sponsor>
  </sponsors>
  <source>University Hospital Southampton NHS Foundation Trust</source>
  <oversight_info>
    <has_dmc>No</has_dmc>
  </oversight_info>
  <brief_summary>
    <textblock>
      Optiflow can be used to prolong the apnoea period under anaesthesia without falls in blood&#xD;
      oxygen saturation. This study is designed to assess whether the Optiflow system can&#xD;
      efficiently replace conventional anaesthetic mask and circuit preoxygenation so that it could&#xD;
      be used in emergency anaesthesia. If so, it would be then be in place in the case of&#xD;
      difficult or failed intubation to maintain oxygenation ie: it could preoxygenate and then&#xD;
      maintain oxygenation seamlessly.&#xD;
    </textblock>
  </brief_summary>
  <detailed_description>
    <textblock>
      The Optiflow device is used to deliver high flow humidified oxygen/air via nasal cannulae to&#xD;
      patients who have respiratory problems. More recently it has been used in patients having&#xD;
      surgery on their larynx who are intentionally paralysed under anaesthesia where the surgeon&#xD;
      does not want any tubes in the airway. This makes access for surgery easier/possible. Perhaps&#xD;
      surprisingly, these patients can be left apnoeic for 30 minutes without falls in blood oxygen&#xD;
      levels. The lungs are oxygenated despite there being no in and out breathing/ventilation.&#xD;
&#xD;
      We propose that applying Optiflow at the start of an emergency anaesthetic may be beneficial&#xD;
      when an anaesthetist finds that tracheal intubation is impossible - a &quot;failed intubation&quot;&#xD;
      scenario. Optiflow might maintain oxygenation during further attempts at intubation or until&#xD;
      more skilled anaesthetists arrive.&#xD;
&#xD;
      Another alternative technique presently in common use is for the patient to breathe 100%&#xD;
      oxygen via a facemask and conventional anaesthetic circuit for 3 minutes before anaesthesia&#xD;
      starts (preoxygenation). This fills the functional residual capacity of the lungs to about&#xD;
      90% oxygen giving an oxygen reserve when the breathing stops until the anaesthetist breathes&#xD;
      for them after intubating the trachea. This can result in the maintenance of normal blood&#xD;
      oxygen saturation for several minutes longer than would be the case if the lungs had only&#xD;
      been exposed to air before anaesthesia.&#xD;
&#xD;
      The research question that we ask is whether we can just use Optiflow instead of the&#xD;
      conventional mask/circuit to preoxygenate patients to a similar extent and as quickly as&#xD;
      using a facemask so that, in emergency surgery, Optiflow could be used to preoxygenate and&#xD;
      then already be in place in case there is a failed intubation. This would enable Optiflow to&#xD;
      be used for both purposes seamlessly without the need to switch between the two methods of&#xD;
      oxygenation.&#xD;
&#xD;
      Research to date has not yet identified how long Optiflow needs to be in place before&#xD;
      anaesthesia for it to be able to produce adequate preoxygenation of the lungs before the&#xD;
      patient stops breathing. The 3 minute timing for preoxygenation is important in emergency&#xD;
      cases e.g. when there is an emergency caesarean section to be done and every minute before&#xD;
      the baby is delivered matters. If it were not possible to preoxygenate a patient's lungs&#xD;
      within 3 minutes using Optiflow we would suggest that it is inappropriate to replace&#xD;
      conventional mask pre-oxygenation and that its value in emergency anaesthesia might be&#xD;
      reduced (although it may still have potential for less urgent anaesthesia when it could be&#xD;
      applied for a longer duration before anaesthesia).&#xD;
&#xD;
      This will be a pilot study with 20 healthy volunteer students as subjects who will undergo an&#xD;
      up / down sequential analysis of Optiflow pre-oxygenation. They will be recruited from&#xD;
      posters inviting them to consider enrolling in the project. They will receive a subject&#xD;
      information sheet and will provide written informed consent.&#xD;
&#xD;
      On the study day an individual subject will lie supine on a trolley and the Optiflow device&#xD;
      will be fitted ready to administer humidified 100% oxygen at 45 l/min via the device's nasal&#xD;
      cannulae. The subject will be asked to breathe normally with a closed mouth and the device&#xD;
      will be switched on.&#xD;
&#xD;
      The initial test period will be for 3 minutes and at the end of that time the device will be&#xD;
      turned off with the subject holding their breath in inspiration and the subject will then&#xD;
      exhale and then breathe normally via a mouthpiece which has a side sampling port connected to&#xD;
      a standard gas monitor (as used during anaesthesia) which will measure and display the&#xD;
      expired oxygen percentage. This is known to equate very well to the alveolar oxygen fraction&#xD;
      in healthy subjects and the target value will be 85%.&#xD;
&#xD;
      After the initial test the subject will be asked to walk around breathing room air for at&#xD;
      least 15 minutes to return their lung gases to pre test normality.&#xD;
&#xD;
      The process will then be repeated as before but for a different duration:&#xD;
&#xD;
      If the target of 85% had not been reached within 3 minutes the 2nd test would be for 5&#xD;
      minutes.&#xD;
&#xD;
      If the 85% target had been reached the 2nd test would be reduced to 2.5 minutes.&#xD;
&#xD;
      The test runs would continue in the same up/down fashion until the minimum time required to&#xD;
      reach 85% had been identified (to the nearest 30 seconds) or the subject had done test runs&#xD;
      up to 10 minutes long without reaching the target.&#xD;
&#xD;
      If the subject wished to split the test runs over more than one session that would be&#xD;
      accommodated. They would also be free to leave the study at any time if they so desired.&#xD;
&#xD;
      Subsequent subjects will have an initial test duration adjusted to the average of the&#xD;
      previous subjects so that they may not be required to undergo as many tests (this presumes&#xD;
      that there is not too much variation within the population) and will be less inconvenienced.&#xD;
    </textblock>
  </detailed_description>
  <overall_status>Unknown status</overall_status>
  <last_known_status>Recruiting</last_known_status>
  <start_date>October 2016</start_date>
  <completion_date type="Anticipated">January 2017</completion_date>
  <primary_completion_date type="Anticipated">January 2017</primary_completion_date>
  <phase>N/A</phase>
  <study_type>Interventional</study_type>
  <has_expanded_access>No</has_expanded_access>
  <study_design_info>
    <allocation>N/A</allocation>
    <intervention_model>Single Group Assignment</intervention_model>
    <primary_purpose>Basic Science</primary_purpose>
    <masking>None (Open Label)</masking>
  </study_design_info>
  <primary_outcome>
    <measure>time to end tidal oxygen content of 0.85</measure>
    <time_frame>less than 10 minutes</time_frame>
    <description>time to this end point will be found by up/down sequential tests</description>
  </primary_outcome>
  <enrollment type="Anticipated">20</enrollment>
  <condition>Preoxygenation, Apnoea, Anaesthesia</condition>
  <intervention>
    <intervention_type>Device</intervention_type>
    <intervention_name>optiflow</intervention_name>
    <description>Optiflow device used for preoxygenation</description>
  </intervention>
  <eligibility>
    <criteria>
      <textblock>
        Inclusion Criteria:&#xD;
&#xD;
          -  healthy (ASA1or 2)&#xD;
&#xD;
        Exclusion Criteria:&#xD;
&#xD;
          -  respiratory disease&#xD;
      </textblock>
    </criteria>
    <gender>Female</gender>
    <minimum_age>20 Years</minimum_age>
    <maximum_age>35 Years</maximum_age>
    <healthy_volunteers>Accepts Healthy Volunteers</healthy_volunteers>
  </eligibility>
  <overall_contact>
    <last_name>patrick butler, MBChB</last_name>
    <phone>02380777222</phone>
    <phone_ext>6283</phone_ext>
    <email>patrick.butler@uhs.nhs.uk</email>
  </overall_contact>
  <location>
    <facility>
      <name>University Hospital Southampton</name>
      <address>
        <city>Southampton</city>
        <state>Hants</state>
        <zip>SO166YD</zip>
        <country>United Kingdom</country>
      </address>
    </facility>
    <status>Recruiting</status>
    <contact>
      <last_name>Patrick Butler, MBChB</last_name>
      <phone>02380777222</phone>
      <phone_ext>6283</phone_ext>
      <email>patrick.butler@uhs.nhs.uk</email>
    </contact>
  </location>
  <location_countries>
    <country>United Kingdom</country>
  </location_countries>
  <verification_date>December 2016</verification_date>
  <study_first_submitted>December 1, 2016</study_first_submitted>
  <study_first_submitted_qc>December 1, 2016</study_first_submitted_qc>
  <study_first_posted type="Estimate">December 5, 2016</study_first_posted>
  <last_update_submitted>December 1, 2016</last_update_submitted>
  <last_update_submitted_qc>December 1, 2016</last_update_submitted_qc>
  <last_update_posted type="Estimate">December 5, 2016</last_update_posted>
  <responsible_party>
    <responsible_party_type>Sponsor</responsible_party_type>
  </responsible_party>
  <patient_data>
    <sharing_ipd>No</sharing_ipd>
  </patient_data>
  <pending_results>
    <submitted>October 6, 2017</submitted>
    <returned>July 20, 2018</returned>
    <submitted>October 18, 2018</submitted>
    <returned>October 18, 2018</returned>
    <submitted>April 8, 2021</submitted>
    <returned>April 9, 2021</returned>
  </pending_results>
  <!-- Results have not yet been posted for this study                                          -->
</clinical_study>


download date: ClinicalTrials.gov processed this data on September 20, 2023
link text: Link to the current ClinicalTrials.gov record.
url: https://clinicaltrials.gov/ct2/show/NCT02981511
org study id: RHMCRI0333
nct id: NCT02981511
lead sponsor: 
has dmc: No
Optiflow can be used to prolong the apnoea period under anaesthesia without falls in blood
      oxygen saturation. This study is designed to assess whether the Optiflow system can
      efficiently replace conventional anaesthetic mask and circuit preoxygenation so that it could
      be used in emergency anaesthesia. If so, it would be then be in place in the case of
      difficult or failed intubation to maintain oxygenation ie: it could preoxygenate and then
      maintain oxygenation seamlessly.
The Optiflow device is used to deliver high flow humidified oxygen/air via nasal cannulae to
      patients who have respiratory problems. More recently it has been used in patients having
      surgery on their larynx who are intentionally paralysed under anaesthesia where the surgeon
      does not want any tubes in the airway. This makes access for surgery easier/possible. Perhaps
      surprisingly, these patients can be left apnoeic for 30 minutes without falls in blood oxygen
      levels. The lungs are oxygenated despite there being no in and out breathing/ventilation.

      We propose that applying Optiflow at the start of an emergency anaesthetic may be beneficial
      when an anaesthetist finds that tracheal intubation is impossible - a "failed intubation"
      scenario. Optiflow might maintain oxygenation during further attempts at intubation or until
      more skilled anaesthetists arrive.

      Another alternative technique presently in common use is for the patient to breathe 100%
      oxygen via a facemask and conventional anaesthetic circuit for 3 minutes before anaesthesia
      starts (preoxygenation). This fills the functional residual capacity of the lungs to about
      90% oxygen giving an oxygen reserve when the breathing stops until the anaesthetist breathes
      for them after intubating the trachea. This can result in the maintenance of normal blood
      oxygen saturation for several minutes longer than would be the case if the lungs had only
      been exposed to air before anaesthesia.

      The research question that we ask is whether we can just use Optiflow instead of the
      conventional mask/circuit to preoxygenate patients to a similar extent and as quickly as
      using a facemask so that, in emergency surgery, Optiflow could be used to preoxygenate and
      then already be in place in case there is a failed intubation. This would enable Optiflow to
      be used for both purposes seamlessly without the need to switch between the two methods of
      oxygenation.

      Research to date has not yet identified how long Optiflow needs to be in place before
      anaesthesia for it to be able to produce adequate preoxygenation of the lungs before the
      patient stops breathing. The 3 minute timing for preoxygenation is important in emergency
      cases e.g. when there is an emergency caesarean section to be done and every minute before
      the baby is delivered matters. If it were not possible to preoxygenate a patient's lungs
      within 3 minutes using Optiflow we would suggest that it is inappropriate to replace
      conventional mask pre-oxygenation and that its value in emergency anaesthesia might be
      reduced (although it may still have potential for less urgent anaesthesia when it could be
      applied for a longer duration before anaesthesia).

      This will be a pilot study with 20 healthy volunteer students as subjects who will undergo an
      up / down sequential analysis of Optiflow pre-oxygenation. They will be recruited from
      posters inviting them to consider enrolling in the project. They will receive a subject
      information sheet and will provide written informed consent.

      On the study day an individual subject will lie supine on a trolley and the Optiflow device
      will be fitted ready to administer humidified 100% oxygen at 45 l/min via the device's nasal
      cannulae. The subject will be asked to breathe normally with a closed mouth and the device
      will be switched on.

      The initial test period will be for 3 minutes and at the end of that time the device will be
      turned off with the subject holding their breath in inspiration and the subject will then
      exhale and then breathe normally via a mouthpiece which has a side sampling port connected to
      a standard gas monitor (as used during anaesthesia) which will measure and display the
      expired oxygen percentage. This is known to equate very well to the alveolar oxygen fraction
      in healthy subjects and the target value will be 85%.

      After the initial test the subject will be asked to walk around breathing room air for at
      least 15 minutes to return their lung gases to pre test normality.

      The process will then be repeated as before but for a different duration:

      If the target of 85% had not been reached within 3 minutes the 2nd test would be for 5
      minutes.

      If the 85% target had been reached the 2nd test would be reduced to 2.5 minutes.

      The test runs would continue in the same up/down fashion until the minimum time required to
      reach 85% had been identified (to the nearest 30 seconds) or the subject had done test runs
      up to 10 minutes long without reaching the target.

      If the subject wished to split the test runs over more than one session that would be
      accommodated. They would also be free to leave the study at any time if they so desired.

      Subsequent subjects will have an initial test duration adjusted to the average of the
      previous subjects so that they may not be required to undergo as many tests (this presumes
      that there is not too much variation within the population) and will be less inconvenienced.
allocation: N/A
intervention model: Single Group Assignment
primary purpose: Basic Science
masking: None (Open Label)
measure: time to end tidal oxygen content of 0.85
time frame: less than 10 minutes
description: time to this end point will be found by up/down sequential tests
intervention type: Device
intervention name: optiflow
description: Optiflow device used for preoxygenation
criteria: 
gender: Female
minimum age: 20 Years
maximum age: 35 Years
healthy volunteers: Accepts Healthy Volunteers
last name: patrick butler, MBChB
phone: 02380777222
phone ext: 6283
email: patrick.butler@uhs.nhs.uk
facility: 
status: Recruiting
contact: 
country: United Kingdom
responsible party type: Sponsor
sharing ipd: No
submitted: October 6, 2017
returned: July 20, 2018
submitted: October 18, 2018
returned: October 18, 2018
submitted: April 8, 2021
returned: April 9, 2021