Miller Blade for Intubation in Adults

January 2, 2026 updated by: Medical University of Lodz

Comparison of the Miller Laryngoscope and the Macintosh Laryngoscope During Endotracheal Intubation in Adult Patients

The study compares laryngeal view obtained with standard Macintosh blade laryngoscope and Miller blade laryngoscope in adult patients. After introduction to general anesthesia anesthesiologist will perform laryngoscopy with one chosen blade and after evaluation of visualisation of entrance to larynx will change blade to second one and repeat evaluation.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Tracheal intubation is the gold standard of the airway in the operating theater in patients undergoing general anesthesia for surgery, in intensive care and emergency medicine, in patients with severe respiratory failure, which is life-threatening. The laryngoscope is a device used to visualize the entrance to the airway and the subsequent insertion of the tracheal tube into the trachea and main bronchus. Macintosh and Miller laryngoscopes have been used in clinical practice for several decades. The Macintosh laryngoscope is most commonly used for the intubation of adult patients, and the Miller laryngoscope for the intubation of newborns, including premature babies and pediatric patients. Currently, when we are dealing with the sars covid-19 virus epidemic and a large number of patients with respiratory failure requiring endotracheal intubation and replacement ventilation, searching for a device that facilitates endotracheal intubation, especially by people with little experience in using it, in the absence of anesthesiologists, seems to be justified. The aim of the study will be to assess the possibility of using the Miller's laryngoscope for intubation of adult patients and to compare it with the most frequently used Macintosh laryngoscope in this group of patients. The study will include patients scheduled for elective surgery under general endotracheal anesthesia. After a typical induction of anesthesia with the use of short-term intravenous anesthetics, opioids and muscle relaxants, appropriate for the planned surgery and a specific patient, after obtaining complete neuromuscular blockade, a Macintosh laryngoscope will be inserted to perform direct laryngoscopy and assess the exit to the respiratory tract with the help of the Cormack scale. Then the laryngoscope will be removed, the patient will receive active oxygen therapy to increase blood oxygenation to the value of 99-100%, and then an additional dose of intravenous anesthetic will be administered and a second direct laryngoscopy will be performed with the Miller's laryngoscope with a subsequent assessment of airway entry using the scale Cormack. The patient will then be intubated and connected to an anesthesia machine.

Study Type

Interventional

Enrollment (Actual)

1130

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Poland
      • Lodz, Poland, 90-153
        • Medical University of Lodz, Poland

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 90 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • all patients scheduled for elective procedures under general anesthesia with endotracheal intubation

Exclusion Criteria:

  • patients with expected difficutl intubation requiring advanced intubation techniques
  • with injuries of the cervical spine, or for surgery in the cervical spine
  • patients with increased intracranial and intraocular pressure, with vascular changes in the CNS and other parts of the body
  • patients with ASA III and above
  • patients who do not consent to participate in the study

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Diagnostic
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
No Intervention: Macintosh blade
laryngoscopy with Macintosh blade
Active Comparator: Miller blade
laryngoscopy with Miller blade in the same patient
Device: Miller blade
After laryngoscopy with Macintosh blade patient will be evaluated in laryngoscopy with Miller blade

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Number of Grade of view of entrance to larynx
Time Frame: immediate
Laryngoscopy with Macintosh blade and then with Miller blade in the same patient, grade of view estimated in Cormack-lehane scale and POGO - percentage of glottis opening
immediate

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Medical University of Lodz

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

May 20, 2022

Primary Completion (Actual)

December 1, 2022

Study Completion (Actual)

February 1, 2023

Study Registration Dates

First Submitted

August 8, 2022

First Submitted That Met QC Criteria

August 8, 2022

First Posted (Actual)

August 10, 2022

Study Record Updates

Last Update Posted (Estimated)

January 6, 2026

Last Update Submitted That Met QC Criteria

January 2, 2026

Last Verified

July 1, 2022

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • RNN/103/22/KE

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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