Intubation, IntratrachealNCT04439487
Thyromental Height Test as a New Method for Prediction of Difficult Intubation in Obese Patients
An observational study of Intubation, Intratracheal and Obesity, run by Medical University of Silesia at 2 sites in Poland.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Intubation, Intratracheal, Obesity, Predictive Value of Tests
- What is being tested?
- Anthropometric measurements during routine preoperative visit and Assesment of intubation parameters during induction of general anaesthesia
- How many people
- 300 participants
- Where
- 2 sitesPoland
- Study dates
- 1 Jun 2020to 1 Jun 2021
- Phase
- Observational
- 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 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Studied population will consist of consecutive obese, adult patients (BMI ≥30 kg/m2) qualified for elective surgical procedures, requiring general anaesthesia, direct laryngoscopy and intubation.
Who may be able to join
- qualification for elective surgical procedures, requiring general anaesthesia, direct laryngoscopy and intubation
- consent for participation in the trail
- age ≥18 years
- BMI ≥30 kg/m2
Who cannot join
- BMI ≤30 kg/m2
- patients overweight due to ascites or tumor
- emergency procedures
- visible anatomic abnormalities
- patients scheduled for awake fibreoptic intubation
- intubation failure
- lack of consent for participation in the trail
Trial locations and contacts
2 sites in 1 country.
Poland2 sites
Medical University of Gdansk
Gdansk, Pomeranian Voivodeship, 80-214
Samodzielny Publiczny Szpital Kliniczny nr 1
Zabrze, Silesian Voivodeship, 41-800
About this study
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.
Read the detailed description
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.
- Being tested
- Anthropometric measurements during routine preoperative visit, Assesment of intubation parameters during induction of general anaesthesia
- Keywords
- Difficult Intubation, Obesity, Thyromental Height Test
- Medical subject headings
- Obesity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Anthropometric measurements during routine preoperative visitDiagnostic test
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
Assesment of intubation parameters during induction of general anaesthesiaOther
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.
| Study group | Role | What they receive |
|---|---|---|
| Obese patients requiring general anesthesia | 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. Receives: Diagnostic Test: Anthropometric measurements during routine preoperative visit; Other: Assesment of intubation parameters during induction of general anaesthesia |
What is being measured
The primary outcome is the main question the study is designed to answer.
Score in Cormack-Lehane scale (CL).
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.
Measured: Intraoperatively (an average of 5 minutes)
Thyromental height (TMH). [mm]
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.
Measured: Preoperatively (an average of 24 hours)
Secondary outcomes (10)
Thyromental distance (TMD). [cm]
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.
Measured: Preoperatively (an average of 24 hours)
Sternomental distance (SMD). [cm]
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.
Measured: Preoperatively (an average of 24 hours)
Score in modified Mallampati test (MMT).
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.
Measured: Preoperatively (an average of 24 hours)
Mouth opening (MO). [cm]
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.
Measured: Preoperatively (an average of 24 hours)
Neck circumference (NC). [cm]
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.
Measured: Preoperatively (an average of 24 hours)
Intubation time. [s]
Intubation time is defined as a time from direct laryngoscopy commencement to confirmation of endotracheal tube placement and noted during induction of general anaesthesia.
Measured: Intraoperatively (an average of 5 minutes)
Intubation difficulty.
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.
Measured: Intraoperatively (an average of 5 minutes)
Number of intubation attempts.
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.
Measured: Intraoperatively (an average of 5 minutes)
Use of bougie.
Necessity to use bougie during induction of general anaesthesia is noted.
Measured: Intraoperatively (an average of 5 minutes)
Technique modification.
Necessity to modify technique of laryngoscopy or intubation is noted.
Measured: Intraoperatively (an average of 5 minutes)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Jun 2020
- Study start1 Jun 2020
- Primary completion1 Jun 2021 (estimated)
- Study completion1 Jun 2021 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Intubation, IntratrachealStudies of the same condition, open and under way.
- 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
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 300 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Medical University of Silesia
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Piotr Palaczyński, Medical University of Silesia
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04439487
- Sponsor's protocol ID
- TMHT-02
- Status last verified
- Jun 2020
- First submitted
- 4 Jun 2020
- Last updated
- 19 Jun 2020
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 19 Jun 2020. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Thyromental Height Test as a New Method for Prediction of Difficult Intubation in Obese Patients
- ClinicalTrials.gov ID
- NCT04439487
- Acronym / sponsor ID
- TMHT-02
- Keywords
- Difficult Intubation, Obesity, Thyromental Height Test
- Study type
- Observational
- Recruitment status
- Unknown status
- Enrolment
- 300 participants (estimated)
- Lead sponsor
- Medical University of SilesiaUniversity, hospital or other
- Study start
- 1 Jun 2020 (actual)
- Primary completion
- 1 Jun 2021 (estimated)
- Study completion
- 1 Jun 2021 (estimated)
- First posted
- 19 Jun 2020 (actual)
- 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.
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.
Detailed description
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.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Obese patients requiring general anesthesia | – | Diagnostic Test: Anthropometric measurements during routine preoperative visit, Other: Assesment of intubation parameters during induction of general anaesthesiaGroup 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. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Studied population will consist of consecutive obese, adult patients (BMI ≥30 kg/m2) qualified for elective surgical procedures, requiring general anaesthesia, direct laryngoscopy and intubation.
Key inclusion criteria (4 listed)
- qualification for elective surgical procedures, requiring general anaesthesia, direct laryngoscopy and intubation
- consent for participation in the trail
- age ≥18 years
- BMI ≥30 kg/m2
Key exclusion criteria (7 listed)
- BMI ≤30 kg/m2
- patients overweight due to ascites or tumor
- emergency procedures
- visible anatomic abnormalities
- patients scheduled for awake fibreoptic intubation
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 |
|---|---|---|
| Anthropometric measurements during routine preoperative visitDuring 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 | Diagnostic test | Obese patients requiring general anesthesia |
| Assesment of intubation parameters during induction of general anaesthesiaDuring 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. | Other | Obese patients requiring general anesthesia |
Primary outcome
Score in Cormack-Lehane scale (CL).
Time frame: Intraoperatively (an average of 5 minutes)
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.
Thyromental height (TMH). [mm]
Time frame: Preoperatively (an average of 24 hours)
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.
10 secondary outcomes
Thyromental distance (TMD). [cm]
Time frame: Preoperatively (an average of 24 hours)
Sternomental distance (SMD). [cm]
Time frame: Preoperatively (an average of 24 hours)
Score in modified Mallampati test (MMT).
Time frame: Preoperatively (an average of 24 hours)
Mouth opening (MO). [cm]
Time frame: Preoperatively (an average of 24 hours)
Neck circumference (NC). [cm]
Time frame: Preoperatively (an average of 24 hours)
Intubation time. [s]
Time frame: Intraoperatively (an average of 5 minutes)
Intubation difficulty.
Time frame: Intraoperatively (an average of 5 minutes)
Number of intubation attempts.
Time frame: Intraoperatively (an average of 5 minutes)
Use of bougie.
Time frame: Intraoperatively (an average of 5 minutes)
Technique modification.
Time frame: Intraoperatively (an average of 5 minutes)
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 19 Jun 2020.
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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.
The record lists no contact. Use the official record to reach the sponsor.
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Intubation, Intratracheal and Obesity, run by Medical University of Silesia at 2 sites in Poland.
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 4 inclusion and 7 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: status not confirmed, as of the sponsor's last update on 19 Jun 2020. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in Poland. 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?
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?
Score in Cormack-Lehane scale (CL). (time frame: Intraoperatively (an average of 5 minutes)). The study lists 2 primary outcomes in all. 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 19 Jun 2020.