TMHT - Difficult Intubation Prediction Using Videolaryngoscopy

Thyromental Height Test as a New Method for Prediction of Difficult Intubation Using Videolaryngoscopy

The purpose of this study is to assess the usefulness of the Thyromental Height Test in prediction of difficult intubation using videolaryngoscopy and double lumen endotracheal tubes in patients scheduled for elective thoracic procedures.

Study Overview

• Status: Completed
• Conditions: Predictive Value of Tests; Intubation
• Intervention / Treatment: Procedure: Macintosh laryngoscopy; Procedure: McGrath MAC video laryngoscopy

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.

There is a number of anthropometric scales and tests used for predicting difficult intubation. 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 the trial is to assess the clinical usefulness of TMHT in prediction of difficult intubation using videolaryngoscopy and double lumen endotracheal tubes in patients scheduled for elective thoracic surgical procedures. The secondary aim is to evaluate usefulness of other commonly used predictive tests associated with difficult intubation.

During routine, preoperative anaesthetic visit thyromental height, thyromental distance, sternomental distance and Mallampati scale score are assessed. Then, during videolaryngoscopy and intubation, score in Cormack-Lehane scale and occurrence of difficult intubation are noted.

• Study Type: Interventional
• Enrollment (Actual): 200
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Poland
  • Silesia
    • Zabrze, Silesia, Poland, 41-800
      • Samodzielny Publiczny Szpital Kliniczny nr 1

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• patients scheduled for elective thoracic procedures, requiring general anaesthesia, videolaryngoscopy and intubation with a Robert-Shaw type double lumen endotracheal tubes
• written, informed consent for participation in the trail
• older than 18 years

Exclusion Criteria:

• emergency procedures
• visible anatomic abnormalities
• patients scheduled for awake fibre optic intubation
• lack of consent for participation in the trail

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: Macintosh laryngoscope; direct laryngoscope - laryngoscope with Macintosh blade	Procedure: Macintosh laryngoscopy; intubation with MAcintosh laryngoscopy after anesthetic induction
Other: McGrath videolaryngoscope; McGrath Videolaryngoscope	Procedure: McGrath MAC video laryngoscopy; intubation with McGrath MAC videolaryngoscopy after anesthetic induction

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Thyromental height	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), in supine position with mouth closed, measured with a depth gauge during routine preoperative anaesthetic visit.	From August 6 2018 to August 5 2019.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
score in Cormack-Lehane scale	During videolaryngoscopy 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.	From August 6 2018 to August 5 2019.
Thyromental distance	The distance between the thyroid prominence and the most anterior part of the mental prominence of the mandible, measured with a standard centigrade ruler as the distance in centimetres with the patient in supine position, head fully extended, mouth closed, during routine preoperative anaesthetic visit.	From August 6 2018 to August 5 2019.
Sternomental distance	The distance in centimetres between the superior border of the manubrium sterni and the bony point of the mentum, with the patient in supine position, head fully extended, mouth closed, measured with a standard centigrade ruler, during routine preoperative anaesthetic visit.	From August 6 2018 to August 5 2019.
core in modified Mallampati test	The oropharyngeal view is assessed in sitting position, mouth maximally opened, tongue protruded, without phonation, measured during routine preoperative anaesthetic visit.	From August 6 2018 to August 5 2019.
distance of mouth opening	Measured as a distance between the lower and upper incisors with a tape measure (Standard, Hoechstmas, Sulzbach, Germany) as a distance in centimetres. Patients are in sitting position with mouth maximally opened, tongue retracted and without phonation.	From August 6 2018 to August 5 2019.

Collaborators and Investigators

• Sponsor: Medical University of Silesia
• Investigators: Study Director: Hanna Misiołek, MD PhD, Medical University of Silesia; Study Chair: Szymon Białka, MD, Medical University of Silesia

Study record dates

Study Major Dates

• Study Start (Actual): August 6, 2018
• Primary Completion (Actual): November 5, 2019
• Study Completion (Actual): November 5, 2019

Study Registration Dates

• First Submitted: August 5, 2018
• First Submitted That Met QC Criteria: August 23, 2018
• First Posted (Actual): August 27, 2018

Study Record Updates

• Last Update Posted (Actual): April 14, 2020
• Last Update Submitted That Met QC Criteria: April 12, 2020
• Last Verified: April 1, 2020

More Information

Terms related to this study

• Keywords: Difficult Intubation; Thyromental Height Test; Videolaryngoscopy
• Other Study ID Numbers: TMHT-03

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No