Evaluation of Functional Dimensions of Macintosh Laryngoscope Blade During Direct Laryngoscopy in Patients With Normal Mouth Opening
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ClinicalTrials.gov Identifier: NCT02639897 |
Recruitment Status :
Recruiting
First Posted : December 28, 2015
Last Update Posted : October 30, 2020
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Direct laryngoscopy and intubation is an essential initial aspect of airway access during general anesthesia. To perform the procedure effectively, it requires adequate mouth opening, head and neck movement, and a normal temporo-mandibular joint mobility. Any issue with the above three results in a compromised upper airway at the outset and the condition is known as anticipated difficult airway, i.e. an airway that is difficult to access with conventional laryngoscopy and intubation methods. To overcome the difficulty, either one has to resort to newer advanced technique and equipment or the available conventional technique needs to be refined and modified to suit the requirement. While the former requires extraordinary expertise and finances, an option difficult to achieve in developing countries; the latter warrants focused interest to develop alternative approach with the same set of equipments.
Since submucous fibrosis and the associated restricted mouth opening have taken the proposition of an epidemic owing to widespread use of betel nut and tobacco; these patients, when requiring surgery, are difficult candidates for GA and airway control. The fact that, when they arrive as pre-surgical candidates, they have variable degree of mouth opening restriction, which if approached with a strategy, may be amenable to conventional control of airway. If investigators paint all the patients with mouth restriction as difficult airway, it will result in uncalled surgical, economic, health system and psychological burden. Therefore, it is prudent to undertake research relating to refinement of airway access techniques with the easily available, cheap and user- friendly equipment (conventional laryngoscope), such that a proportion of above stated burden can be reduced.
In view of the above, investigators plan to undertake a study to enhance our working knowledge with a conventional laryngoscope (Macintosh) to facilitate ways to control the airway difficulty secondary to mouth opening restriction. Investigators believe that the prospective knowledge thus generated would help us identify whether there is a feasibility of conventional airway management or an alternative advanced access technique is needed in the first place. This will prevent undue cancellations, delayed surgeries, and patient morbidity.
Condition or disease | Intervention/treatment |
---|---|
Submucous Fibrosis | Other: Direct Laryngoscopy |

Study Type : | Observational |
Estimated Enrollment : | 100 participants |
Observational Model: | Cohort |
Time Perspective: | Prospective |
Official Title: | Evaluation of Functional Dimensions of Macintosh Blade During Laryngoscopy in Patients With Normal Mouth Opening: Development of a Feasibility Model for Facilitation of Laryngoscopy in Cases of Mouth Opening Restriction Due to Submucous Fibrosis |
Study Start Date : | October 2016 |
Estimated Primary Completion Date : | June 2022 |
Estimated Study Completion Date : | July 2022 |
- Other: Direct Laryngoscopy
Tracheal intubation with direct laryngoscopy using Macintosh laryngoscope blade
- Macintosh Blade Length Measurement (in centimeters) [ Time Frame: 0 to 5-minutes ]Length of Macintosh blade size 3 and 4 as such (static) and during active direct laryngoscopy (active).
- Macintosh Blade Width Measurement (in centimeters) [ Time Frame: 0 to 5-minutes ]Width of Macintosh blade size 3 and 4 as such (static) and during active direct laryngoscopy (active).
- Inter-incisor Angle on Macintosh Blade Contact Point (in degrees) [ Time Frame: 0 to 5-minutes ]The angle formed by the line between the two contact points, viz. a point formed by upper incisor contact of upper flange curve (convex) of the Macintosh laryngoscope blade, and a point of contact between the lower incisor contact with lower flange curve (concave curve) of the Macintosh laryngoscope blade. The line formed by joining these two contact points with the baseline of the laryngoscope will form an angle. This angle will be noted as functional separation of eugnathic, retrognathic or prognathic maxilo-mandibular orientation
- Upper Airway Measurements (in centimeters) [ Time Frame: 0 to 5-minutes ]Mento-hyoid, mento-thyroid distance, and the length of sub-mandibular triangle perpendicular
- Correlation Assessment [ Time Frame: 0 to 5-minutes ]The functional laryngoscope length will be tested for correlation with the linear neck (Mento-hyoid distance, menlo-thyroid distance ) and mandibular distances (perpendicular to sub-mandibular triangle) and the most consistent one will be taken

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Ages Eligible for Study: | 20 Years to 65 Years (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Sampling Method: | Non-Probability Sample |
Inclusion Criteria:
- Consenting adults
- Both gender
- Age: 20-65 years
- Normal preoperative upper airway evaluation and without the presence of anticipated airway access difficulty
- Patients scheduled for surgery under general anaesthesia with airway control by direct laryngoscopy and tracheal intubation
Exclusion Criteria:
- Patient refusal
- Anticipated airway access difficulty
- Edentulous patients
- Patients with dental problem (missing tooth, overlap, cosmetic treatment)
- Vulnerable Patients: High risk situation, major surgery, extremes of age, obstetric patients
- Previously difficult airway

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02639897
Contact: Nitin Sethi, DNB | 00919717494498 | nitinsethi77@yahoo.co.in | |
Contact: Amitabh Dutta, MD | 00919810848064 | duttaamitabh@yahoo.co.in |
India | |
Sir Ganga Ram Hospital | Recruiting |
New Delhi, India, 110060 | |
Contact: Amitabh Dutta, MD +919810848064 duttaamitabh@yahoo.co.in | |
Contact: Nitin Sethi, DNB +919717494498 nitinsethi77@yahoo.co.in | |
Principal Investigator: Amitabh Dutta, MD | |
Principal Investigator: Ameya Pappu, MBBS | |
Principal Investigator: Nitin Sethi, DNB | |
Sub-Investigator: Prabhat Choudhary, MD | |
Sub-Investigator: Manish Gupta, MD | |
Sub-Investigator: Savitar Malhotra, MD | |
Sub-Investigator: Bhuwan C Panday, MD | |
Sub-Investigator: Shvet Mahajan, DA, DNB | |
Sub-Investigator: Jayashree Sood, MD, FFARCS |
Study Director: | Amitabh Dutta, MD | Sir Ganga Ram Hospital, New Delhi, INDIA | |
Study Chair: | Ameya Pappu, MBBS | Sir Ganga Ram Hospital, New Delhi, INDIA | |
Principal Investigator: | Nitin Sethi, DNB | Sir Ganga Ram Hospital, New Delhi, INDIA |
Responsible Party: | Dr Nitin Sethi, Consultant, Sir Ganga Ram Hospital |
ClinicalTrials.gov Identifier: | NCT02639897 |
Other Study ID Numbers: |
EC/10/15/901 |
First Posted: | December 28, 2015 Key Record Dates |
Last Update Posted: | October 30, 2020 |
Last Verified: | October 2020 |
Fibrosis Pathologic Processes |