<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/NCT04439487</url>
  </required_header>
  <id_info>
    <org_study_id>TMHT-02</org_study_id>
    <nct_id>NCT04439487</nct_id>
  </id_info>
  <brief_title>Thyromental Height Test as a New Method for Prediction of Difficult Intubation in Obese Patients</brief_title>
  <official_title>Thyromental Height Test as a New Method for Prediction of Difficult Intubation in Obese Patients</official_title>
  <sponsors>
    <lead_sponsor>
      <agency>Medical University of Silesia</agency>
      <agency_class>Other</agency_class>
    </lead_sponsor>
  </sponsors>
  <source>Medical University of Silesia</source>
  <oversight_info>
    <is_fda_regulated_drug>No</is_fda_regulated_drug>
    <is_fda_regulated_device>No</is_fda_regulated_device>
  </oversight_info>
  <brief_summary>
    <textblock>
      The main objective of this trial is to assess the clinical usefulness of thyromental height&#xD;
      test (TMHT) in prediction of difficult intubation in obese patients scheduled for elective&#xD;
      surgical procedures. The secondary aim is to evaluate usefulness of other commonly used&#xD;
      predictive tests associated with difficult intubation in obese patients.&#xD;
    </textblock>
  </brief_summary>
  <detailed_description>
    <textblock>
      Successful and fast intubation are crucial for the safety of general anaesthesia. Failed&#xD;
      intubation and acute hypoxia remain among the major contributing factors of anaesthesia&#xD;
      related deaths. Difficult intubation prevalence in literature is very inconsistent and varies&#xD;
      between 1.5-20% of cases in general population, to even 50% in obese Thai population.&#xD;
&#xD;
      Obesity remains a challenging problem in perioperative care. It is assumed that the airway&#xD;
      access may be restricted due to anatomic changes resulting from excess body weight. There are&#xD;
      factors like diagnosed obstructive sleep apnoea or large neck circumference that also relate&#xD;
      to occurrence of difficult intubation in obese patients.&#xD;
&#xD;
      There is a number of anthropometric scales and tests used for predicting difficult intubation&#xD;
      in obese patients. However, none of them appears to be sensitive and specific enough to&#xD;
      effectively predict difficult intubation.&#xD;
&#xD;
      Recently, simple and non-invasive test predicting difficult intubation was&#xD;
      introduced-thyromental height test (TMHT). It shows promise as a more effective substitution&#xD;
      for frequently cited anthropometric measures. It is based on the height between the anterior&#xD;
      border of the thyroid cartilage and the anterior border of the mentum, measured while the&#xD;
      patient lies in the supine position with closed mouth.&#xD;
&#xD;
      The main objective of this trial is to assess the clinical usefulness of TMHT in prediction&#xD;
      of difficult intubation in obese patients scheduled for elective surgical procedures. The&#xD;
      secondary aim is to evaluate usefulness of other commonly used predictive tests associated&#xD;
      with difficult intubation in obese patients.&#xD;
    </textblock>
  </detailed_description>
  <overall_status>Unknown status</overall_status>
  <last_known_status>Active, not recruiting</last_known_status>
  <start_date type="Actual">June 1, 2020</start_date>
  <completion_date type="Anticipated">June 1, 2021</completion_date>
  <primary_completion_date type="Anticipated">June 1, 2021</primary_completion_date>
  <study_type>Observational</study_type>
  <has_expanded_access>No</has_expanded_access>
  <study_design_info>
    <observational_model>Cohort</observational_model>
    <time_perspective>Prospective</time_perspective>
  </study_design_info>
  <primary_outcome>
    <measure>Score in Cormack-Lehane scale (CL).</measure>
    <time_frame>Intraoperatively (an average of 5 minutes)</time_frame>
    <description>During direct laryngoscopy after the induction of general anesthesia the laryngeal view is graded in Cormack-Lehane Scale by the laryngoscopist. Grade I is assigned when the glottis is fully visible, grade II when the glottis is partially visible, grade III when only the epiglottis is visible and grade IV when neither glottis nor epiglottis is visible.</description>
  </primary_outcome>
  <primary_outcome>
    <measure>Thyromental height (TMH). [mm]</measure>
    <time_frame>Preoperatively (an average of 24 hours)</time_frame>
    <description>Thyromental height is defined as the height between the anterior border of the thyroid cartilage (on the thyroid notch just between the 2 thyroid laminae) and the anterior border of the mentum (on the mental protuberance of the mandible). It is measured with a depth gauge during routine preoperative anaesthetic visit in supine position and closed mouth.</description>
  </primary_outcome>
  <secondary_outcome>
    <measure>Thyromental distance (TMD). [cm]</measure>
    <time_frame>Preoperatively (an average of 24 hours)</time_frame>
    <description>Thyromental distance is measured during routine preoperative visit as a height between the anterior border of the thyroid cartilage (on the thyroid notch just between the 2 thyroid laminae) and the anterior border of the mentum (on the mental protuberance of the mandible) with a depth gauge (21460605, Limit, Alingsås, Sweden) in millimetres, with the patient in supine position and closed mouth.</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Sternomental distance (SMD). [cm]</measure>
    <time_frame>Preoperatively (an average of 24 hours)</time_frame>
    <description>Sternomental distance is measured during routine preoperative visit between the superior border of the manubrium sterni and the most anterior part of the mental prominence of the mandible with a tape measure (Standard, Hoechstmas, Sulzbach, Germany) as a distance in centimetres, with the patient in supine position, head fully extended, mouth closed.</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Score in modified Mallampati test (MMT).</measure>
    <time_frame>Preoperatively (an average of 24 hours)</time_frame>
    <description>The oropharyngeal view is assessed according to modified Mallampati scale in sitting position, mouth maximally opened, tongue protruded, without phonation during routine preoperative anaesthetic visit. Grade I is assigned when the soft palate, uvula, fauces and pillars are fully visible, grade II when the soft palate, major part of uvula and fauces are visible, grade III when soft palate and base of uvula are visible and grade IV when only hard palate is visible.</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Mouth opening (MO). [cm]</measure>
    <time_frame>Preoperatively (an average of 24 hours)</time_frame>
    <description>Mouth opening is measured as a distance between the lower and upper incisors with a tape measure (Standard, Hoechstmas, Sulzbach, Germany) in centimetres. Patients are in sitting position with mouth maximally opened, tongue retracted and without phonation.</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Neck circumference (NC). [cm]</measure>
    <time_frame>Preoperatively (an average of 24 hours)</time_frame>
    <description>Neck circumference is measured at the level of the cricoid cartilage horizontally with a tape measure (Standard, Hoechstmas, Sulzbach, Germany) as a circumference in centimetres in the sitting position during routine preoperative visit.</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Intubation time. [s]</measure>
    <time_frame>Intraoperatively (an average of 5 minutes)</time_frame>
    <description>Intubation time is defined as a time from direct laryngoscopy commencement to confirmation of endotracheal tube placement and noted during induction of general anaesthesia.</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Intubation difficulty.</measure>
    <time_frame>Intraoperatively (an average of 5 minutes)</time_frame>
    <description>Subjective evaluation of intubation difficulty is noted during induction of general anaesthesia. Grade I is defined as an easy intubation, grade II a moderate intubation and grade III as a difficult intubation.</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Number of intubation attempts.</measure>
    <time_frame>Intraoperatively (an average of 5 minutes)</time_frame>
    <description>Number of intubation attempts defined as a failed direct laryngoscopy without the use of endotracheal tube or insertion of endotracheal tube beyond the teeth line is noted during induction of general anaesthesia.</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Use of bougie.</measure>
    <time_frame>Intraoperatively (an average of 5 minutes)</time_frame>
    <description>Necessity to use bougie during induction of general anaesthesia is noted.</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Technique modification.</measure>
    <time_frame>Intraoperatively (an average of 5 minutes)</time_frame>
    <description>Necessity to modify technique of laryngoscopy or intubation is noted.</description>
  </secondary_outcome>
  <number_of_groups>1</number_of_groups>
  <enrollment type="Anticipated">300</enrollment>
  <condition>Intubation, Intratracheal</condition>
  <condition>Obesity</condition>
  <condition>Predictive Value of Tests</condition>
  <arm_group>
    <arm_group_label>Obese patients requiring general anesthesia</arm_group_label>
    <description>Group consists of consecutive, adult, obese patients undergoing elective surgical procedures requiring general anaesthesia, direct laryngoscopy and intubation. All patients undergo general anesthesia according to a standardised protocol. They are preoxygenated with 100% oxygen breathed through a face mask for 3-5 minutes. Induction of general anaesthesia is achieved with propofol 1,5-2 mg·kg-1 (of Ideal Body Weight) and 0,1mg fentanyl or sufentanil 10µg. Muscle relaxation is accomplished with rocuronium 0.6 mg ·kg-1 (of Ideal Body Weight). Depth of muscular blockade is monitored using Train of Four (TOF) method. The first laryngoscopy attempt is performed at TOF 0. The patient is placed in an optimal, sniffing or ramped position as appropriate and a #3 or #4 Macintosh blade is used. Successful intubation is confirmed with bilateral auscultation and capnography.</description>
  </arm_group>
  <intervention>
    <intervention_type>Diagnostic Test</intervention_type>
    <intervention_name>Anthropometric measurements during routine preoperative visit</intervention_name>
    <description>During routine preoperative anaesthetic visit and physical examination the following predictive test measurements are obtained by a research team member not involved in the further assessment of laryngoscopy: score in modified Mallampati test, Thyromental height, Sternomental distance, Thyromental distance, Neck circumference, Mouth opening distance</description>
    <arm_group_label>Obese patients requiring general anesthesia</arm_group_label>
  </intervention>
  <intervention>
    <intervention_type>Other</intervention_type>
    <intervention_name>Assesment of intubation parameters during induction of general anaesthesia</intervention_name>
    <description>During induction of general anaesthesia and intubation research team member not involved in obtaining anthropometric measurements notes Number of intubation attempts, Intubation time, Subjective intubation difficulty, Use of bougie and Need of technique modification.</description>
    <arm_group_label>Obese patients requiring general anesthesia</arm_group_label>
  </intervention>
  <eligibility>
    <study_pop>
      <textblock>
        Studied population will consist of consecutive obese, adult patients (BMI ≥30 kg/m2)&#xD;
        qualified for elective surgical procedures, requiring general anaesthesia, direct&#xD;
        laryngoscopy and intubation.&#xD;
      </textblock>
    </study_pop>
    <sampling_method>Probability Sample</sampling_method>
    <criteria>
      <textblock>
        Inclusion Criteria:&#xD;
&#xD;
          -  qualification for elective surgical procedures, requiring general anaesthesia, direct&#xD;
             laryngoscopy and intubation&#xD;
&#xD;
          -  consent for participation in the trail&#xD;
&#xD;
          -  age ≥18 years&#xD;
&#xD;
          -  BMI ≥30 kg/m2&#xD;
&#xD;
        Exclusion Criteria:&#xD;
&#xD;
          -  BMI ≤30 kg/m2&#xD;
&#xD;
          -  patients overweight due to ascites or tumor&#xD;
&#xD;
          -  emergency procedures&#xD;
&#xD;
          -  visible anatomic abnormalities&#xD;
&#xD;
          -  patients scheduled for awake fibreoptic intubation&#xD;
&#xD;
          -  intubation failure&#xD;
&#xD;
          -  lack of consent for participation in the trail&#xD;
      </textblock>
    </criteria>
    <gender>All</gender>
    <minimum_age>18 Years</minimum_age>
    <maximum_age>N/A</maximum_age>
    <healthy_volunteers>No</healthy_volunteers>
  </eligibility>
  <location>
    <facility>
      <name>Medical University of Gdansk</name>
      <address>
        <city>Gdańsk</city>
        <state>Pomerania</state>
        <zip>80-214</zip>
        <country>Poland</country>
      </address>
    </facility>
  </location>
  <location>
    <facility>
      <name>Samodzielny Publiczny Szpital Kliniczny nr 1</name>
      <address>
        <city>Zabrze</city>
        <state>Silesia</state>
        <zip>41-800</zip>
        <country>Poland</country>
      </address>
    </facility>
  </location>
  <location_countries>
    <country>Poland</country>
  </location_countries>
  <verification_date>June 2020</verification_date>
  <study_first_submitted>June 4, 2020</study_first_submitted>
  <study_first_submitted_qc>June 18, 2020</study_first_submitted_qc>
  <study_first_posted type="Actual">June 19, 2020</study_first_posted>
  <last_update_submitted>June 18, 2020</last_update_submitted>
  <last_update_submitted_qc>June 18, 2020</last_update_submitted_qc>
  <last_update_posted type="Actual">June 19, 2020</last_update_posted>
  <responsible_party>
    <responsible_party_type>Principal Investigator</responsible_party_type>
    <investigator_affiliation>Medical University of Silesia</investigator_affiliation>
    <investigator_full_name>Piotr Palaczyński</investigator_full_name>
    <investigator_title>Principal Investigator</investigator_title>
  </responsible_party>
  <keyword>Difficult Intubation</keyword>
  <keyword>Obesity</keyword>
  <keyword>Thyromental Height Test</keyword>
  <condition_browse>
    <!-- CAUTION:  The following MeSH terms are assigned with an imperfect algorithm            -->
    <mesh_term>Obesity</mesh_term>
  </condition_browse>
  <intervention_browse>
    <!-- CAUTION:  The following MeSH terms are assigned with an imperfect algorithm            -->
    <mesh_term>Anesthetics</mesh_term>
  </intervention_browse>
  <!-- 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/NCT04439487
org study id: TMHT-02
nct id: NCT04439487
lead sponsor: 
is fda regulated drug: No
is fda regulated device: No
The main objective of this trial is to assess the clinical usefulness of thyromental height
      test (TMHT) in prediction of difficult intubation in obese patients scheduled for elective
      surgical procedures. The secondary aim is to evaluate usefulness of other commonly used
      predictive tests associated with difficult intubation in obese patients.
Successful and fast intubation are crucial for the safety of general anaesthesia. Failed
      intubation and acute hypoxia remain among the major contributing factors of anaesthesia
      related deaths. Difficult intubation prevalence in literature is very inconsistent and varies
      between 1.5-20% of cases in general population, to even 50% in obese Thai population.

      Obesity remains a challenging problem in perioperative care. It is assumed that the airway
      access may be restricted due to anatomic changes resulting from excess body weight. There are
      factors like diagnosed obstructive sleep apnoea or large neck circumference that also relate
      to occurrence of difficult intubation in obese patients.

      There is a number of anthropometric scales and tests used for predicting difficult intubation
      in obese patients. However, none of them appears to be sensitive and specific enough to
      effectively predict difficult intubation.

      Recently, simple and non-invasive test predicting difficult intubation was
      introduced-thyromental height test (TMHT). It shows promise as a more effective substitution
      for frequently cited anthropometric measures. It is based on the height between the anterior
      border of the thyroid cartilage and the anterior border of the mentum, measured while the
      patient lies in the supine position with closed mouth.

      The main objective of this trial is to assess the clinical usefulness of TMHT in prediction
      of difficult intubation in obese patients scheduled for elective surgical procedures. The
      secondary aim is to evaluate usefulness of other commonly used predictive tests associated
      with difficult intubation in obese patients.
observational model: Cohort
time perspective: Prospective
measure: Score in Cormack-Lehane scale (CL).
time frame: Intraoperatively (an average of 5 minutes)
description: During direct laryngoscopy after the induction of general anesthesia the laryngeal view is graded in Cormack-Lehane Scale by the laryngoscopist. Grade I is assigned when the glottis is fully visible, grade II when the glottis is partially visible, grade III when only the epiglottis is visible and grade IV when neither glottis nor epiglottis is visible.
measure: Thyromental height (TMH). [mm]
time frame: Preoperatively (an average of 24 hours)
description: Thyromental height is defined as the height between the anterior border of the thyroid cartilage (on the thyroid notch just between the 2 thyroid laminae) and the anterior border of the mentum (on the mental protuberance of the mandible). It is measured with a depth gauge during routine preoperative anaesthetic visit in supine position and closed mouth.
measure: Thyromental distance (TMD). [cm]
time frame: Preoperatively (an average of 24 hours)
description: Thyromental distance is measured during routine preoperative visit as a height between the anterior border of the thyroid cartilage (on the thyroid notch just between the 2 thyroid laminae) and the anterior border of the mentum (on the mental protuberance of the mandible) with a depth gauge (21460605, Limit, Alingsås, Sweden) in millimetres, with the patient in supine position and closed mouth.
measure: Sternomental distance (SMD). [cm]
time frame: Preoperatively (an average of 24 hours)
description: Sternomental distance is measured during routine preoperative visit between the superior border of the manubrium sterni and the most anterior part of the mental prominence of the mandible with a tape measure (Standard, Hoechstmas, Sulzbach, Germany) as a distance in centimetres, with the patient in supine position, head fully extended, mouth closed.
measure: Score in modified Mallampati test (MMT).
time frame: Preoperatively (an average of 24 hours)
description: The oropharyngeal view is assessed according to modified Mallampati scale in sitting position, mouth maximally opened, tongue protruded, without phonation during routine preoperative anaesthetic visit. Grade I is assigned when the soft palate, uvula, fauces and pillars are fully visible, grade II when the soft palate, major part of uvula and fauces are visible, grade III when soft palate and base of uvula are visible and grade IV when only hard palate is visible.
measure: Mouth opening (MO). [cm]
time frame: Preoperatively (an average of 24 hours)
description: Mouth opening is measured as a distance between the lower and upper incisors with a tape measure (Standard, Hoechstmas, Sulzbach, Germany) in centimetres. Patients are in sitting position with mouth maximally opened, tongue retracted and without phonation.
measure: Neck circumference (NC). [cm]
time frame: Preoperatively (an average of 24 hours)
description: Neck circumference is measured at the level of the cricoid cartilage horizontally with a tape measure (Standard, Hoechstmas, Sulzbach, Germany) as a circumference in centimetres in the sitting position during routine preoperative visit.
measure: Intubation time. [s]
time frame: Intraoperatively (an average of 5 minutes)
description: Intubation time is defined as a time from direct laryngoscopy commencement to confirmation of endotracheal tube placement and noted during induction of general anaesthesia.
measure: Intubation difficulty.
time frame: Intraoperatively (an average of 5 minutes)
description: Subjective evaluation of intubation difficulty is noted during induction of general anaesthesia. Grade I is defined as an easy intubation, grade II a moderate intubation and grade III as a difficult intubation.
measure: Number of intubation attempts.
time frame: Intraoperatively (an average of 5 minutes)
description: Number of intubation attempts defined as a failed direct laryngoscopy without the use of endotracheal tube or insertion of endotracheal tube beyond the teeth line is noted during induction of general anaesthesia.
measure: Use of bougie.
time frame: Intraoperatively (an average of 5 minutes)
description: Necessity to use bougie during induction of general anaesthesia is noted.
measure: Technique modification.
time frame: Intraoperatively (an average of 5 minutes)
description: Necessity to modify technique of laryngoscopy or intubation is noted.
arm group label: Obese patients requiring general anesthesia
description: Group consists of consecutive, adult, obese patients undergoing elective surgical procedures requiring general anaesthesia, direct laryngoscopy and intubation. All patients undergo general anesthesia according to a standardised protocol. They are preoxygenated with 100% oxygen breathed through a face mask for 3-5 minutes. Induction of general anaesthesia is achieved with propofol 1,5-2 mg·kg-1 (of Ideal Body Weight) and 0,1mg fentanyl or sufentanil 10µg. Muscle relaxation is accomplished with rocuronium 0.6 mg ·kg-1 (of Ideal Body Weight). Depth of muscular blockade is monitored using Train of Four (TOF) method. The first laryngoscopy attempt is performed at TOF 0. The patient is placed in an optimal, sniffing or ramped position as appropriate and a #3 or #4 Macintosh blade is used. Successful intubation is confirmed with bilateral auscultation and capnography.
intervention type: Diagnostic Test
intervention name: Anthropometric measurements during routine preoperative visit
description: During routine preoperative anaesthetic visit and physical examination the following predictive test measurements are obtained by a research team member not involved in the further assessment of laryngoscopy: score in modified Mallampati test, Thyromental height, Sternomental distance, Thyromental distance, Neck circumference, Mouth opening distance
arm group label: Obese patients requiring general anesthesia
intervention type: Other
intervention name: Assesment of intubation parameters during induction of general anaesthesia
description: During induction of general anaesthesia and intubation research team member not involved in obtaining anthropometric measurements notes Number of intubation attempts, Intubation time, Subjective intubation difficulty, Use of bougie and Need of technique modification.
arm group label: Obese patients requiring general anesthesia
study pop: 
sampling method: Probability Sample
criteria: 
gender: All
minimum age: 18 Years
maximum age: N/A
healthy volunteers: No
facility: 
facility: 
country: Poland
responsible party type: Principal Investigator
investigator affiliation: Medical University of Silesia
investigator full name: Piotr Palaczyński
investigator title: Principal Investigator
mesh term: Obesity
mesh term: Anesthetics