Clinical trial NCT04439487: Thyromental Height Test as a New Method for Prediction of Difficult Intubation in Obese Patients
Official title: Thyromental Height Test as a New Method for Prediction of Difficult Intubation in Obese Patients
Study type: OBSERVATIONAL
Overall status: UNKNOWN
Conditions: Intubation, Intratracheal
Obesity
Predictive Value of Tests
Keywords: Difficult Intubation
Obesity
Thyromental Height Test
Lead sponsor: Medical University of Silesia
Sponsor class: OTHER
First posted: 2020-06-19
Enrollment: 300
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: PROBABILITY_SAMPLE
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.

Brief 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. 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.

Eligibility criteria: Inclusion Criteria:

* 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

Exclusion Criteria:

* 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

Primary outcomes:
measure: Score in Cormack-Lehane scale (CL).
timeFrame: Intraoperatively (an average of 5 minutes)
measure: Thyromental height (TMH). [mm]
timeFrame: Preoperatively (an average of 24 hours)
Secondary outcomes:
measure: Thyromental distance (TMD). [cm]
timeFrame: Preoperatively (an average of 24 hours)
measure: Sternomental distance (SMD). [cm]
timeFrame: Preoperatively (an average of 24 hours)
measure: Score in modified Mallampati test (MMT).
timeFrame: Preoperatively (an average of 24 hours)
measure: Mouth opening (MO). [cm]
timeFrame: Preoperatively (an average of 24 hours)
measure: Neck circumference (NC). [cm]
timeFrame: Preoperatively (an average of 24 hours)
measure: Intubation time. [s]
timeFrame: Intraoperatively (an average of 5 minutes)
measure: Intubation difficulty.
timeFrame: Intraoperatively (an average of 5 minutes)
measure: Number of intubation attempts.
timeFrame: Intraoperatively (an average of 5 minutes)
measure: Use of bougie.
timeFrame: Intraoperatively (an average of 5 minutes)
measure: Technique modification.
timeFrame: Intraoperatively (an average of 5 minutes)
Other outcomes:
Locations:
city: Gdańsk
country: Poland
facility: Medical University of Gdansk
state: Pomerania
city: Zabrze
country: Poland
facility: Samodzielny Publiczny Szpital Kliniczny nr 1
state: Silesia
Study officials:
References: