Comparing the Laryngoscopy View Using Miller and Macintosh Laryngoscopy Blades in Infants Under Two Years of Age

This study has been completed.
Sponsor:
Information provided by (Responsible Party):
Jerrold Lerman, State University of New York at Buffalo
ClinicalTrials.gov Identifier:
NCT01717872
First received: October 28, 2012
Last updated: August 1, 2013
Last verified: August 2013
  Purpose

To compare the laryngoscopy view using two standard clinical devices, the Macintosh and Miller laryngoscopy blades, in infants between one day and two years of age.

Miller blades (straight blades) are more commonly used than MacIntosh blades (curved) in pediatric clinical practice in some institutions especially in infants. The anatomy of infant airway has traditionally been considered to lend itself to advantages of the Miller blade. Some argue that the Miller blade offers a superior view of the laryngeal inlet because it lifts the epiglottis. However, others use the Miller blade to expose the larynx without lifting the epiglottis, supposedly to avoid traumatizing it. Despite the long-standing use of these blades, more than 50 years, no systematic study has ever compared the laryngoscopy views of the Miller and Macintosh blades in infants.


Condition Intervention
Vocal Cord View
Device: Laryngoscope blade

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Single Blind (Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Comparing the Laryngoscopy View Using Miller and Macintosh Laryngoscopy Blades in Infants Under Two Years of Age

Further study details as provided by State University of New York at Buffalo:

Primary Outcome Measures:
  • The view of the larynx (glottis opening) as determined by POGO score (percentage of glottic opening). [ Time Frame: 11/2012 to 07/2013 ] [ Designated as safety issue: No ]
    POGO score with the Miller blade lifting the epiglottis compared with the score with the Macintosh blade not lifting the epiglottis


Secondary Outcome Measures:
  • POGO score for the Miller or Miller blade with and without lifting the epiglottis [ Time Frame: 11/2012 to 07/2013 ] [ Designated as safety issue: No ]

Enrollment: 50
Study Start Date: October 2012
Study Completion Date: July 2013
Primary Completion Date: July 2013 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Macintosh laryngoscope blade
A photo of the larynx will be taken with the Macintosh laryngoscope blade lifting and not lifting the epiglottis. The view of the larynx will be assessed using the POGO score by a blinded assessor.
Device: Laryngoscope blade
The POGO score will be used to assess the percent of the glottis that can be seen with each of the blades while lifting or not lifting the epiglottis
Other Names:
  • Macintosh laryngoscope blade
  • Miller laryngoscope blade
Active Comparator: Miller laryngoscope blade
A photo of the larynx will be taken with the Miller laryngoscope blade lifting and not lifting the epiglottis. The view of the larynx will be assessed using the POGO score by a blinded assessor.
Device: Laryngoscope blade
The POGO score will be used to assess the percent of the glottis that can be seen with each of the blades while lifting or not lifting the epiglottis
Other Names:
  • Macintosh laryngoscope blade
  • Miller laryngoscope blade

Detailed Description:
  • After Institutional Review Board approval, the patients meeting inclusion criteria will be selected from the Operating room elective surgical list.
  • They will be randomized to one of the two groups: a #1 Miller or Macintosh blade.
  • After obtaining informed consent from the parent or the legal guardian, monitors (electrocardiogram, non-invasive blood pressure monitor and pulse oximeter) that are routine induction of anesthesia will be applied and anesthesia will be induced using an inhalation technique with sevoflurane, nitrous oxide and oxygen. An intravenous cannula will then be placed. The child will then receive a standard intubating dose of a muscle relaxant (rocuronium 0.5-1 mg/kg). The lungs will be mask ventilated using 100% oxygen in Sevoflurane for 3 minutes to allow appropriate time for the muscle relaxant to be fully effective. At that time, the randomized code for that child will be opened and laryngoscopy will be performed with either a Miller or MacIntosh blade as indicated by the code.
  • The best possible glottic view will be obtained by ensuring the following steps. The child's head will be positioned in the Magill position, muscle relaxant will be administered, firm forward traction will be applied to the laryngoscope handle, and if needed, external laryngeal manipulation will be applied.
  • During the same laryngoscopy, the best glottic visualization will be obtained with the blade lifting the epiglottis and not lifting the epiglottis, in random order (by flipping a coin). This difference is a matter of moving the position of the blade back without removing the blade from the larynx.
  • The two views will be recorded by a second doctor using a SONY camera at the mouth adjacent to the laryngoscope handle.
  • Photos of the glottic opening will be graded using the POGO scale (Ref1) by a third (blinded) anesthesiologist.
  • All of the intubations and image acquisition will be performed by Drs. Yuvesh Passi, Jerrold Lerman or Chris Heard.
  • The images obtained will not have patient identifiers included. They will be stored in a secure file once the study is completed that will be accessed only by investigators involved in the study.
  • No patient identifiers will be included on any documentation apart from the source documents.
  • The research data will be stored in a locked office of Dr. Lerman (Room 251) in Department of Anesthesia, Women and Children's Hospital of Buffalo during and after the study for security to protect subject privacy and confidentiality.
  • There will be no payments or compensation to the study subjects

The primary hypothesis of this study is to compare the view of the larynx with Miller blade while lifting the epiglottis to the Macintosh blade lifting the tongue, in infants and children <2 years of age. However, views will be obtained with the Miller and Macintosh blades both lifting and not lifting the epiglottis and comparisons between pairs of measurements will be performed. In order for to detect superiority of one technique over the other, we will need a difference in the POGO scores of 25 points with a standard deviation of 25 points, yielding a sample size of 15 children in each group. To account for photographic difficulties, unreadable photos as well as dropouts, we will enroll 25 children in each group. Therefore a total of 50 children will be enrolled.

  Eligibility

Ages Eligible for Study:   up to 2 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • ASA 1 and ASA 2 infants and children
  • Age <2 years of age
  • All racial and ethnic origin
  • Scheduled for elective surgery
  • Fasting patients who are unmedicated preoperatively

Exclusion Criteria:

  • History of difficult airway
  • Severe asthma
  • Premature birth
  • ICU stay for more than a week following delivery
  • Acute or chronic pulmonary or neuromuscular diseases
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01717872

Locations
United States, New York
Women and Childrens Hospital of Buffalo
Buffalo, New York, United States, 14222
Sponsors and Collaborators
State University of New York at Buffalo
Investigators
Principal Investigator: Jerrold Lerman, MD SUNY at Buffalo, Women and Children's Hospital of Buffalo
  More Information

No publications provided

Responsible Party: Jerrold Lerman, Clinical Professor of Anesthesiology, State University of New York at Buffalo
ClinicalTrials.gov Identifier: NCT01717872     History of Changes
Other Study ID Numbers: Lerman Blade study
Study First Received: October 28, 2012
Last Updated: August 1, 2013
Health Authority: United States: Institutional Review Board

Keywords provided by State University of New York at Buffalo:
glottis, laryngoscopy, laryngoscope blade

ClinicalTrials.gov processed this record on July 31, 2014