Glottic Visualization & Ease of Intubation With Different Laryngoscope Blades

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01352299
Recruitment Status : Completed
First Posted : May 11, 2011
Last Update Posted : May 11, 2011
Information provided by:
Tata Memorial Hospital

Brief Summary:

Orotracheal intubation the commonest method used to secure and maintain airway during anaesthesia. A variety of methods are available for orotracheal intubation such as digital or tactile method, use of lighted orotracheal intubating stylet, use of intubating LMA (which is becoming increasing popular, particularly in cased of anticipated difficult intubation), fibreoptic endoscopic orotracheal intubation (also used when a difficulty is predicted), and conventional and most common method, direct laryngoscopy. Orotracheal intubation is most commonly achieved after visualization of laryngeal inlet with direct laryngoscopy following induction of general anaesthesia and muscle relaxation achieved by administration of a muscle relaxant.

Due to the hazards seen with failed intubation, anaesthetists are also on the lookout for techniques which will improve visualization of the laryngeal inlet, i.e. glottis. View obtained during laryngoscopy can be classified in a variety of ways such as Cormack Lehane grading, the percentage of glottic opening (POGO Score)Literature suggests that straight blade gives better glottic visualization while tracheal intubation is easier with the curved blade. We therefore wanted to compare the Macintosh and Miller laryngoscope blades in terms of visualization of Laryngeal inlet and ease of intubation in patients with normal predicted intubation. We also compared the McCoy blade, a modified curved blade, and the Trueview Laryngoscope, which incorporates a prism in a straight blade, for glottic view and ease of intubation.

Condition or disease Intervention/treatment Phase
Tracheal Intubation Morbidity Device: Macintosh Laryngoscope blade Device: MacCoy Device: Miller Device: TrueView Not Applicable

  Show Detailed Description

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 120 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Official Title: Comparison of Visualisation of Laryngeal Inlet and Ease of Intubation With Different Laryngoscope Blades.
Study Start Date : August 2008
Actual Primary Completion Date : October 2008
Actual Study Completion Date : October 2008

Arm Intervention/treatment
Active Comparator: Macintosh
Laryngoscopy performed with Macintosh Laryngoscope
Device: Macintosh Laryngoscope blade
Laryngoscopy performed with Macintosh Laryngoscope
Other Name: Conventional Curved laryngoscope blade

Active Comparator: McCoy
Laryngoscopy performed with MacCoy Laryngoscope
Device: MacCoy
Laryngoscopy performed with MacCoy Laryngoscope
Other Name: Curved laryngoscope blade with a hinged tip

Active Comparator: Miller
Laryngoscopy performed with Miller Laryngoscope
Device: Miller
Laryngoscopy performed with Miller Laryngoscope
Other Name: Conventional Straight laryngoscope blade

Active Comparator: TrueView
Laryngoscopy performed with TrueView Laryngoscope
Device: TrueView
Laryngoscopy performed with TrueView laryngoscope
Other Name: Straight blade with prism

Primary Outcome Measures :
  1. Visualization of glottis and Ease of Intubation [ Time Frame: During Laryngoscopy and intubation average time 1 minute ]

    Visualization of laryngeal inlet:

    Grade 1: complete glottis visible Grade 2: anterior glottis not seen Grade 3: epiglottis seen but not glottis Grade 4: epiglottis not seen

    Ease of intubation:

    Grade 1: Intubation easy Grade 2: Intubation requiring an increased anterior lifting force and assistance to pull the right corner of the mouth upwards to increase space Grade 3: Intubation requiring multiple attempts and a curved stylet Grade 4: Failure to intubate with the assigned laryngoscope

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Ages Eligible for Study:   18 Years to 70 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Patients in the age group of 18-70 yrs
  • Patients with ASA grade I and II
  • Undergoing surgery under general anaesthesia requiring endotracheal intubation.

Exclusion Criteria:

  • Patient's refusal for consent for study.
  • Patients less than 18 years and more than 70years of age.
  • Pregnant patients
  • Patients with difficult mask ventilation and /or anticipated difficult intubation
  • Patients with pathology in neck, upper respiratory tract and upper alimentary tract.

Information from the National Library of Medicine

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 identifier (NCT number): NCT01352299

Tata Memorial Hopsital
Mumbai, Maharashtra, India, 400012
Sponsors and Collaborators
Tata Memorial Hospital
Principal Investigator: Atul P Kulkarni, MD Anaes Professor Tata Memorial Hospital

Responsible Party: Dr Atul P Kulkarni, Tata Memorial Hospital Identifier: NCT01352299     History of Changes
Other Study ID Numbers: Akulkarni2
First Posted: May 11, 2011    Key Record Dates
Last Update Posted: May 11, 2011
Last Verified: May 2011

Keywords provided by Tata Memorial Hospital:
Macintosh laryngoscope blade
MacCoy laryngoscope blade
Miller laryngoscope blade
TrueView laryngoscope