Intubation;DifficultNCT04716218
Effect of Back up Head Elevated Position on Laryngeal Visualization.
A study testing back up head elevated position in people with Intubation;Difficult, run by Hallym University Kangnam Sacred Heart Hospital at 1 site in South Korea.
Trial summary
In patients with limited neck extension and mouth opening due to reasons including previous radiation therapy in the head and neck area or cervical spine pathology, tracheal intubation with direct laryngoscopy (DL) are challenging because of the difficulty in aligning the oral, pharyngeal, and laryngeal axes in order… Read more about this study
- Who is it for?
- Ages 18 to 80 yearsHealthy volunteers can take part
- Conditions the study is for
- Intubation;Difficult
- What is being tested?
- back up head elevated position
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 64 participants
- Where
- 1 siteSouth Korea
- Study dates
- 18 Jan 2021to 31 Mar 2021
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 80 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- patients of ASA physical status 1-2 who were scheduled for elective surgery under general anaesthesia requiring tracheal intubation
Who cannot join
- if they required rapid sequence induction; had a history of previous difficult direct laryngoscopy and required awake tracheal intubation; were unable or unwilling to provide informed consent; had uncontrolled hypertension; had a history of ischaemic heart disease without optimal control of symptoms; had a history of acute or recent stroke or myocardial infarction; had cervical spine instability or cervical myelopathy; had symptomatic asthma or reactive airway disease requiring daily pharmacological treatment for control of symptoms; or had a history of gastric reflux.
Trial locations and contacts
1 site in 1 country.
South Korea1 site
Kangnam Sacred Heart Hospital, Hallym University College of Medicine
Seoul
About this study
Official title: Effect of Back up Head Elevated Position on Laryngeal Visualization With the Video-laryngoscope in Patients With Simulated Difficult Airway.
In patients with limited neck extension and mouth opening due to reasons including previous radiation therapy in the head and neck area or cervical spine pathology, tracheal intubation with direct laryngoscopy (DL) are challenging because of the difficulty in aligning the oral, pharyngeal, and laryngeal axes in order to visualize the cords. In contrast, video-laryngoscopes (VL) only require alignment of the pharyngeal and laryngeal axes, which lie along much more similar angles when compared with the oral axis. Thus, VL make tracheal intubation easier to accomplish in these patients.
Good patient positioning also maximizes the chance of successful laryngoscopy and tracheal intubation. In difficult airway society 2015 guidelines, advantages of head-up positioning and ramping, which brings the patient's sternum onto the horizontal plane of the external auditory meatus (EAM), are highlighted. In the obese patient, the 'ramped' position should be used routinely because this improves the view during DL. This position is usually achieved by placing blankets or other devices under the patient's head and shoulders, but can also be achieved simply by configuring the operation room (OR) table into a back-up head elevated (BUHE) position. Significantly improved glottic views on DL have been reported with both obese and non-obese adult patients in BUHE position. However, the effect of this simple maneuver on laryngeal visualization with the VL in patients with limited neck extension and mouth opening has not been reported.
The investigators hypothesized that BUHE position might improve laryngeal views and make intubation easier compared to the supine position with the VL in patients with simulated difficult airway (application of a cervical collar to limit mouth opening and neck movement).The investigator investigated primarily the improvement in visualization of the glottis and, secondarily, the ease of tracheal intubation after alignment of the EAM and sternal notch.
- Conditions
- Intubation;Difficult
- Being tested
- back up head elevated position
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
back up head elevated positionProcedure or surgery
The patient was then placed in the back-up position to align the external auditory meatus and sternal notch, which was achieved by breaking the operating table at the hips to prevent patients from sliding off the table.
| Study group | Role | What they receive |
|---|---|---|
| neutral position | Placebo comparator | The initial percentage of glottic opening (POGO) by laryngoscopy was recorded in the ramped position. Thereafter, a second POGO (laryngeal view) was scored in the neutral position and then intubation was performed. Receives: Procedure: back up head elevated position |
| back up head elevated position | Experimental | The initial POGO was recorded in the neutral position. The second POGO was scored in the ramped position and then the trachea was intubated. Receives: Procedure: back up head elevated position |
What is being measured
The primary outcome is the main question the study is designed to answer.
POGO score
percentage of glottic opening
Measured: During laryngeal visualization by laryngoscope over 1 minute period
Secondary outcomes (2)
intubation time
time required for intubation
Measured: The time from the insertion of laryngoscope into oral cavity until its removal over 1 minute period
ease of tracheal intubation
number of optimization procedure to facilitate laryngeal visualization and tracheal intubation
Measured: The time from the insertion of laryngoscope into oral cavity until tracheal intubation over 1minute period
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Jan 2021
- Study start18 Jan 2021
- Primary completion31 Mar 2021
- Study completion31 Mar 2021
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Intubation;DifficultStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 64 participants (actual)
Sponsor and investigators
- Lead sponsor
- Hallym University Kangnam Sacred Heart Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Jun joohyun, Hallym University Kangnam Sacred Heart Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04716218
- Sponsor's protocol ID
- 2020-09-009
- Status last verified
- Jan 2026
- First submitted
- 12 Jan 2021
- Last updated
- 29 Jan 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Chun EH, Chung MH, Kim JE, Kim KM, Lee HS, Son JM, Park J, Jun JH. Effects of head-elevated position on tracheal intubation using a McGrath MAC videolaryngoscope in patients with a simulated difficult airway: a prospective randomized crossover study. BMC Anesthesiol. 2022 May 30;22(1):166. doi: 10.1186/s12871-022-01706-5.
PubMed 35637437
Study at a glance
From the registry record, last updated by the sponsor on 29 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Back up Head Elevated Position on Laryngeal Visualization With the Video-laryngoscope in Patients With Simulated Difficult Airway.
- ClinicalTrials.gov ID
- NCT04716218
- Acronym / sponsor ID
- 2020-09-009
- Conditions
- Intubation;Difficult
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 64 participants (actual)
- Lead sponsor
- Hallym University Kangnam Sacred Heart HospitalUniversity, hospital or other
- Study start
- 18 Jan 2021 (actual)
- Primary completion
- 31 Mar 2021 (actual)
- Study completion
- 31 Mar 2021 (actual)
- First posted
- 20 Jan 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
In patients with limited neck extension and mouth opening due to reasons including previous radiation therapy in the head and neck area or cervical spine pathology, tracheal intubation with direct laryngoscopy (DL) are challenging because of the difficulty in aligning the oral, pharyngeal, and laryngeal axes in order to visualize the cords. In contrast, video-laryngoscopes (VL) only require alignment of the pharyngeal and laryngeal axes, which lie along much more similar angles when compared with the oral axis. Thus, VL make tracheal intubation easier to accomplish in these patients.
Good patient positioning also maximizes the chance of successful laryngoscopy and tracheal intubation. In difficult airway society 2015 guidelines, advantages of head-up positioning and ramping, which brings the patient's sternum onto the horizontal plane of the external auditory meatus (EAM), are highlighted. In the obese patient, the 'ramped' position should be used routinely because this improves the view during DL. This position is usually achieved by placing blankets or other devices under the patient's head and shoulders, but can also be achieved simply by configuring the operation room (OR) table into a back-up head elevated (BUHE) position. Significantly improved glottic views on DL have been reported with both obese and non-obese adult patients in BUHE position. However, the effect of this simple maneuver on laryngeal visualization with the VL in patients with limited neck extension and mouth opening has not been reported.
The investigators hypothesized that BUHE position might improve laryngeal views and make intubation easier compared to the supine position with the VL in patients with simulated difficult airway (application of a cervical collar to limit mouth opening and neck movement).The investigator investigated primarily the improvement in visualization of the glottis and, secondarily, the ease of tracheal intubation after alignment of the EAM and sternal notch.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| neutral position | Placebo comparator | Procedure: back up head elevated positionThe initial percentage of glottic opening (POGO) by laryngoscopy was recorded in the ramped position. Thereafter, a second POGO (laryngeal view) was scored in the neutral position and then intubation was performed. |
| back up head elevated position | Experimental | Procedure: back up head elevated positionThe initial POGO was recorded in the neutral position. The second POGO was scored in the ramped position and then the trachea was intubated. |
Who may qualify
- Ages
- 18 to 80 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- patients of ASA physical status 1-2 who were scheduled for elective surgery under general anaesthesia requiring tracheal intubation
Key exclusion criteria (1 listed)
- if they required rapid sequence induction; had a history of previous difficult direct laryngoscopy and required awake tracheal intubation; were unable or unwilling to provide informed consent; had uncontrolled hypertension; had a history of ischaemic heart disease without optimal control of symptoms; had a history of acute or recent stroke or myocardial infarction; had cervical spine instability or cervical myelopathy; had symptomatic asthma or reactive airway disease requiring daily pharmacological treatment for control of symptoms; or had a history of gastric reflux.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| back up head elevated positionThe patient was then placed in the back-up position to align the external auditory meatus and sternal notch, which was achieved by breaking the operating table at the hips to prevent patients from sliding off the table. | Procedure or surgery | back up head elevated position, neutral position |
Primary outcome
POGO score
Time frame: During laryngeal visualization by laryngoscope over 1 minute period
percentage of glottic opening
2 secondary outcomes
intubation time
Time frame: The time from the insertion of laryngoscope into oral cavity until its removal over 1 minute period
ease of tracheal intubation
Time frame: The time from the insertion of laryngoscope into oral cavity until tracheal intubation over 1minute period
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 29 Jan 2026.
- Derived from this study: PubMed 35637437Chun EH, Chung MH, Kim JE, Kim KM, Lee HS, Son JM, Park J, Jun JH. Effects of head-elevated position on tracheal intubation using a McGrath MAC videolaryngoscope in patients with a simulated difficult airway: a prospective randomized crossover study. BMC Anesthesiol. 2022 May 30;22(1):166. doi: 10.1186/s12871-022-01706-5.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing back up head elevated position in people with Intubation;Difficult, run by Hallym University Kangnam Sacred Heart Hospital at 1 site in South Korea.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 29 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in South Korea. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
POGO score (time frame: During laryngeal visualization by laryngoscope over 1 minute period). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04716218, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 29 Jan 2026.