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Comparison of Video Laryngoscope Using Miller or Macintosh Approach During Endotracheal Intubation

Comparison of Video Laryngoscope Using Miller or Macintosh Approach During Endotracheal Intubation

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05545982
Enrollment
247
Registered
2022-09-19
Start date
2019-10-04
Completion date
2021-11-22
Last updated
2022-09-19

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Difficult Intubation

Keywords

difficult intubation, video laryngoscope

Brief summary

Video laryngoscope has become recommended option during difficult intubation. Guidelines of ASA at 2013 had suggested using video laryngoscope after failure intubation of direct laryngoscope. Varieties of video laryngoscope had been invented with different curves. We call the one which has the same curve of Macintosh laryngoscope as conventional video laryngoscope in this study. Mostly, the way of using conventional video laryngoscope is suggested as Macintosh method. However, with the front positioning camera, Miller method can theoretically improve the glottic opening. We intend to discuss whether using Miller approach with conventional video laryngoscope can improve glottic opening or not.

Detailed description

Video scope can provide better glottic opening by increase the tilting angle of the tip, and the position of camera can provide larger vision angle. However, while the angle increases, the endotracheal tube must fallow the curve, which may require learning curve of the operator. In Glidescope as example, increase the tilting angle can help with glottic exposure, however the steep curve will simultaneously increase the difficulty of inserting the tube or using Magill forceps, especially while intubating double lumen or nasal endotracheal tube. Conventional video laryngoscope in this study indicates the video laryngoscope blade which has the same curve as Macintosh laryngoscope. It mainly improves the glottic view by front positioning camera. Anesthesiologist usually place the tip of the blade at vallecula to expose the glottic which is the conventional ways of using Macintosh blade which we name it as Macintosh method. Placing the tip below the epiglottis and lift it up directly is the way of using Miller blade. Theoretically, the Miller method with conventional video laryngoscope may improve the scale of glottic exposure measured with Cormack-Lehane grade. This is a one-group pretest-posttest study to compare the Cormack-Lehane grade with two different methods in the same patient. This study tends to discuss whether this combination can improve the glottic exposure and preserve the advantage of direct laryngoscope.

Interventions

PROCEDUREVideo laryngoscope with Miller approach

Miller approach indicates lifting epiglottis during laryngoscopy, which is the way of using Miller laryngoscope

Sponsors

Kaohsiung Veterans General Hospital.
Lead SponsorOTHER

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE

Intervention model description

one-group pretest-posttest study

Eligibility

Sex/Gender
ALL
Age
20 Years to No maximum
Healthy volunteers
No

Inclusion criteria

1. Aged\>20 2. Scheduled to received operation that required general anesthesia with endotracheal tube \[3\] ASA I, II

Exclusion criteria

1. Emergent surgery 2. pregnant 3. Limited mouth opening 4. Poor dental condition 5. Airway obstruction (oral tumor, hypopharyngeal cancer….etc) 6. Deep neck infection 7. Allergic to any anesthetic

Design outcomes

Primary

MeasureTime frameDescription
Change of cormack lehane gradeMeasured from glottic exposed by Macintosh approach to Miller approach. Record the cormack lehane grade. The whole precess will be completed within 5 minutes if there are no difficult intubation.Compare the difference of cormack lehane grade using Macintosh ot Miller approach.(cormack lehane grade has four gradings. Grade 1 represent entire glottic opening. Grade 4 represent vocal cord cab not be seen)

Secondary

MeasureTime frameDescription
Post intubation adverse eventVisit the patient daily at post operation day 1 and record any adverse event until post operation day3 or the patient is discharged.Some adverse events are often seen after intubation, such as sore throat, hoarseness....etc.

Countries

Taiwan

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026