Evaluation of Functional Dimensions of Macintosh Laryngoscope Blade During Direct Laryngoscopy in Patients With Normal Mouth Opening

NCT02639897 | Not Yet Recruiting DMC

• 1 other identifier: EC/10/15/901
• Study Type: observational
• Target: 100
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Submucous Fibrosis

Outcome Measures

Primary Outcomes (3)

• Macintosh Blade Length Measurement (in centimeters)

  Length of Macintosh blade size 3 and 4 as such (static) and during active direct laryngoscopy (active).

  0 to 5-minutes

• Macintosh Blade Width Measurement (in centimeters)

  Width of Macintosh blade size 3 and 4 as such (static) and during active direct laryngoscopy (active).

  0 to 5-minutes

• Inter-incisor Angle on Macintosh Blade Contact Point (in degrees)

  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

  0 to 5-minutes

Secondary Outcomes (2)

• Upper Airway Measurements (in centimeters)

  0 to 5-minutes

• Correlation Assessment

  0 to 5-minutes

Interventions

Direct Laryngoscopy OTHER

Tracheal intubation with direct laryngoscopy using Macintosh laryngoscope blade

Eligibility Criteria

• Age: 20 Years - 65 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Patients scheduled for surgery under general anaesthesia with airway control by direct laryngoscopy and tracheal intubation

You may qualify if:

• 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

You may not qualify if:

• 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

Sponsors & Collaborators

• Sir Ganga Ram Hospital: lead

Study Sites (1)

Sir Ganga Ram Hospital

New Delhi, 110060, India

Location

Study Officials

• Amitabh Dutta, MD

  Sir Ganga Ram Hospital, New Delhi, INDIA

  STUDY DIRECTOR

• Ameya Pappu, MBBS

  Sir Ganga Ram Hospital, New Delhi, INDIA

  STUDY CHAIR

• Nitin Sethi, DNB

  Sir Ganga Ram Hospital, New Delhi, INDIA

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Nitin Sethi, DNB

CONTACT

00919717494498; nitinsethi77@yahoo.co.in

Amitabh Dutta, MD

CONTACT

00919810848064; duttaamitabh@yahoo.co.in

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Consultant

Study Record Dates

• First Submitted: December 13, 2015
• First Posted: December 28, 2015
• Study Start (Estimated): October 1, 2026
• Primary Completion (Estimated): June 1, 2030
• Study Completion (Estimated): July 1, 2030
• Last Updated: April 27, 2026

Record last verified: 2026-04

Locations

IN (1)