Elective Surgical PatientsNCT02934347
Comparison of Glottic Views and Intubation Times in the Supine and 25 Degree Back-up Positions
An observational study of Elective Surgical Patients, run by Betsi Cadwaladr University Health Board.
Trial summary
Our hypothesis is that the view of the glottis may be improved by putting all patients requiring intubation in the ramped or back up position while maintaining the classic sniffing position. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Elective Surgical Patients
- What is being tested?
- 25 degree back-up position
- Type of treatment
- Surgery or procedure
- How many people
- 781 participants
- Where
- No sites listed yet
- Study dates
- Feb 2012to Jan 2015
- Phase
- Observational
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
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 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Adult patients who required intubation as part of their routine anaesthesia
Who may be able to join
- Adult surgical patients who required intubation as part of their routine anaesthesia
Who cannot join
- Patients less than 18 years old,
- Patients recognised to have difficult airways where an alternative method of intubation (e.g. fibre optic) was the method of choice,
- Patients undergoing emergency surgery where patient positioning and data collection might cause delay (e.g. exsanguinating patients) or where the supine position is not optimal (e.g. brisk bleeding into the upper airway),
- Patients requiring rapid sequence induction of anaesthesia
About this study
Our hypothesis is that the view of the glottis may be improved by putting all patients requiring intubation in the ramped or back up position while maintaining the classic sniffing position.
Read the detailed description
The sniffing position has traditionally been considered the optimal head position for direct laryngoscopy and is the usual patient position preferred by most anaesthetists. In theory, neck flexion aligns the pharyngeal and laryngeal axes, and head extension at the atlanto-occipital joint aligns the oral axis with these two axes allowing the line of sight to fall on the glottis. It is recognized as the starting head position for direct laryngoscopy because it provides the best chance of adequate exposure.
However the sniffing position does not guarantee adequate exposure in all patients because many other anatomical factors control the final degree of visualization.
To achieve a proper sniffing position in obese patients, the "ramped" (or the back-up) position has been used as this produces better neck flexion and head extension in these patients when compared to the horizontal supine position. Also the forces required to elevate and move the tongue and other tissues out of the line of sight are less when the patients are ramped.
Our hypothesis is that the view of the glottis may be improved by putting all (ie not only obese) patients requiring intubation in the ramped or back up position while maintaining the classic sniffing position.
- Conditions
- Elective Surgical Patients
- Being tested
- 25 degree back-up position
- Keywords
- Intubation, Back-up position; Glottis, View
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
25 degree back-up positionProcedure or surgery
To test whether a 25 degree back-up position improves laryngeal views and makes intubation easier compared to the standard horizontal position
| Study group | Role | What they receive |
|---|---|---|
| Supine | A baseline group of adult patients who required intubation as part of their routine anaesthesia who were intubated in the standard horizontal sniffing position. | |
| Back-up | A subsequent group of similar the patients who had their anaesthesia induced and tracheas intubated in a 25 degree back-up position achieved by flexion of the operating table at the hips Receives: Procedure: 25 degree back-up position |
What is being measured
The primary outcome is the main question the study is designed to answer.
The Best Glottic View Obtained During Laryngoscopy
The best glottic view obtained during laryngoscopy was assessed using the Cormack and Lehane classification by the anaesthetist performing the laryngoscopy.
The Cormack and Lehane classifies glottic views as follows: Grade 1: Most of the glottis is visible, Grade 2: At best almost half of the glottis is seen, at worst only the posterior tip of the arytenoids is seen., Grade 3: Only the epiglottis is visible, Grade 4: No laryngeal structures are visible.
Measured: The view of the glottis was measured once while the patient was being intubated
Secondary outcomes (3)
The Number of Attempts at Both Laryngoscopy and Tracheal Intubation
The number of attempts at both laryngoscopy and tracheal intubation were recorded
Measured: Once at intubation
The Use of Ancillary Equipment
The use of ancillary equipment (e.g. bougie, alternative laryngoscope blades) and manoeuvres (e.g. laryngeal manipulation) were recorded but applied at the intubating anaesthetist's discretion
Measured: Once at intubation
The Time Between the Beginning of Laryngoscopy and Detection of Carbon Dioxide on the End-tidal Carbon Dioxide Monitor
The time between the beginning of laryngoscopy and detection of carbon dioxide on the end-tidal carbon dioxide monitor after the successful placement of the tracheal tube was recorded
Measured: Once at intubation
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 Oct 2016 (estimated)
- Study startFeb 2012
- Primary completionNov 2014
- Study completionJan 2015
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (12)Papers the sponsor has linked to this study.
- Other trials for Elective Surgical PatientsStudies 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
- Observational
- Observational model
- Case-control
- Time perspective
- Prospective
- Enrolment
- 781 participants (actual)
Sponsor and investigators
- Lead sponsor
- Betsi Cadwaladr University Health Board
- Sponsor type
- Other government
- Responsible party
- Principal investigator, Raj M Reddy, Betsi Cadwaladr University Health Board
- Investigators
- Raj M Reddy, FRCA, Principal investigator, Anaesthetic Department, Glan Clwyd Hospital, Betsi Cadwaladr University Health Board
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02934347
- Sponsor's protocol ID
- BetsiCUHB
- Status last verified
- Apr 2017
- First submitted
- 13 Oct 2016
- Last updated
- 11 May 2017
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- Individual data sharing
- Yes: Publish anonymised raw data as supplementary file
Publications
Adnet F, Baillard C, Borron SW, Denantes C, Lefebvre L, Galinski M, Martinez C, Cupa M, Lapostolle F. Randomized study comparing the "sniffing position" with simple head extension for laryngoscopic view in elective surgery patients. Anesthesiology. 2001 Oct;95(4):836-41. doi: 10.1097/00000542-200110000-00009.
PubMed 11605921Bannister FB, Macbeth RG. Direct laryngoscopy and tracheal intubation. Lancet 1944; 2: 651-4
Greenland KB, Edwards MJ, Hutton NJ, Challis VJ, Irwin MG, Sleigh JW. Changes in airway configuration with different head and neck positions using magnetic resonance imaging of normal airways: a new concept with possible clinical applications. Br J Anaesth. 2010 Nov;105(5):683-90. doi: 10.1093/bja/aeq239. Epub 2010 Sep 15.
PubMed 20846964Jackson C. Bronchoscopy and Esophagoscopy: A Manual of Peroral Endoscopy and Laryngeal Surgery. Philadelphia and London: WB Saunders; 1922
Lee BJ, Kang JM, Kim DO. Laryngeal exposure during laryngoscopy is better in the 25 degrees back-up position than in the supine position. Br J Anaesth. 2007 Oct;99(4):581-6. doi: 10.1093/bja/aem095. Epub 2007 Jul 4.
PubMed 17611252Lee HC, Yun MJ, Hwang JW, Na HS, Kim DH, Park JY. Higher operating tables provide better laryngeal views for tracheal intubation. Br J Anaesth. 2014 Apr;112(4):749-55. doi: 10.1093/bja/aet428. Epub 2013 Dec 18.
PubMed 24355831Rao SL, Kunselman AR, Schuler HG, DesHarnais S. Laryngoscopy and tracheal intubation in the head-elevated position in obese patients: a randomized, controlled, equivalence trial. Anesth Analg. 2008 Dec;107(6):1912-8. doi: 10.1213/ane.0b013e31818556ed.
PubMed 19020138Collins JS, Lemmens HJ, Brodsky JB, Brock-Utne JG, Levitan RM. Laryngoscopy and morbid obesity: a comparison of the "sniff" and "ramped" positions. Obes Surg. 2004 Oct;14(9):1171-5. doi: 10.1381/0960892042386869.
PubMed 15527629Lane S, Saunders D, Schofield A, Padmanabhan R, Hildreth A, Laws D. A prospective, randomised controlled trial comparing the efficacy of pre-oxygenation in the 20 degrees head-up vs supine position. Anaesthesia. 2005 Nov;60(11):1064-7. doi: 10.1111/j.1365-2044.2005.04374.x.
PubMed 16229689Dixon BJ, Dixon JB, Carden JR, Burn AJ, Schachter LM, Playfair JM, Laurie CP, O'Brien PE. Preoxygenation is more effective in the 25 degrees head-up position than in the supine position in severely obese patients: a randomized controlled study. Anesthesiology. 2005 Jun;102(6):1110-5; discussion 5A. doi: 10.1097/00000542-200506000-00009.
PubMed 15915022Lebowitz PW, Shay H, Straker T, Rubin D, Bodner S. Shoulder and head elevation improves laryngoscopic view for tracheal intubation in nonobese as well as obese individuals. J Clin Anesth. 2012 Mar;24(2):104-8. doi: 10.1016/j.jclinane.2011.06.015. Epub 2012 Feb 1.
PubMed 22301204Reddy RM, Adke M, Patil P, Kosheleva I, Ridley S; Anaesthetic Department at Glan Clwyd Hospital. Comparison of glottic views and intubation times in the supine and 25 degree back-up positions. BMC Anesthesiol. 2016 Nov 16;16(1):113. doi: 10.1186/s12871-016-0280-4.
PubMed 27852241
Study at a glance
From the registry record, last updated by the sponsor on 11 May 2017. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comparison of Glottic Views and Intubation Times in the Supine and 25 Degree Back-up Positions
- ClinicalTrials.gov ID
- NCT02934347
- Acronym / sponsor ID
- BetsiCUHB
- Conditions
- Elective Surgical Patients
- Keywords
- Intubation, Back-up position; Glottis, View
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 781 participants (actual)
- Lead sponsor
- Betsi Cadwaladr University Health BoardOther government
- Study start
- Feb 2012
- Primary completion
- Nov 2014 (actual)
- Study completion
- Jan 2015 (actual)
- First posted
- 17 Oct 2016 (estimated)
- Results
- Posted 30 Mar 2017
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Our hypothesis is that the view of the glottis may be improved by putting all patients requiring intubation in the ramped or back up position while maintaining the classic sniffing position.
Detailed description
The sniffing position has traditionally been considered the optimal head position for direct laryngoscopy and is the usual patient position preferred by most anaesthetists. In theory, neck flexion aligns the pharyngeal and laryngeal axes, and head extension at the atlanto-occipital joint aligns the oral axis with these two axes allowing the line of sight to fall on the glottis. It is recognized as the starting head position for direct laryngoscopy because it provides the best chance of adequate exposure.
However the sniffing position does not guarantee adequate exposure in all patients because many other anatomical factors control the final degree of visualization.
To achieve a proper sniffing position in obese patients, the "ramped" (or the back-up) position has been used as this produces better neck flexion and head extension in these patients when compared to the horizontal supine position. Also the forces required to elevate and move the tongue and other tissues out of the line of sight are less when the patients are ramped.
Our hypothesis is that the view of the glottis may be improved by putting all (ie not only obese) patients requiring intubation in the ramped or back up position while maintaining the classic sniffing position.
Study design
- Observational model
- Case-control
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Supine | – | –A baseline group of adult patients who required intubation as part of their routine anaesthesia who were intubated in the standard horizontal sniffing position. |
| Back-up | – | Procedure: 25 degree back-up positionA subsequent group of similar the patients who had their anaesthesia induced and tracheas intubated in a 25 degree back-up position achieved by flexion of the operating table at the hips |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Adult patients who required intubation as part of their routine anaesthesia
Key inclusion criteria (1 listed)
- Adult surgical patients who required intubation as part of their routine anaesthesia
Key exclusion criteria (4 listed)
- Patients less than 18 years old,
- Patients recognised to have difficult airways where an alternative method of intubation (e.g. fibre optic) was the method of choice,
- Patients undergoing emergency surgery where patient positioning and data collection might cause delay (e.g. exsanguinating patients) or where the supine position is not optimal (e.g. brisk bleeding into the upper airway),
- Patients requiring rapid sequence induction of anaesthesia
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 |
|---|---|---|
| 25 degree back-up positionTo test whether a 25 degree back-up position improves laryngeal views and makes intubation easier compared to the standard horizontal position | Procedure or surgery | Back-up |
Primary outcome
The Best Glottic View Obtained During Laryngoscopy
Time frame: The view of the glottis was measured once while the patient was being intubated
The best glottic view obtained during laryngoscopy was assessed using the Cormack and Lehane classification by the anaesthetist performing the laryngoscopy. The Cormack and Lehane classifies glottic views as follows: Grade 1: Most of the glottis is visible, Grade 2: At best almost half of the glottis is seen, at worst only the posterior tip of the arytenoids is seen., Grade 3: Only the epiglottis is visible, Grade 4: No laryngeal structures are visible.
3 secondary outcomes
The Number of Attempts at Both Laryngoscopy and Tracheal Intubation
Time frame: Once at intubation
The Use of Ancillary Equipment
Time frame: Once at intubation
The Time Between the Beginning of Laryngoscopy and Detection of Carbon Dioxide on the End-tidal Carbon Dioxide Monitor
Time frame: Once at intubation
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 May 2017.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Background: PubMed 11605921Adnet F, Baillard C, Borron SW, Denantes C, Lefebvre L, Galinski M, Martinez C, Cupa M, Lapostolle F. Randomized study comparing the "sniffing position" with simple head extension for laryngoscopic view in elective surgery patients. Anesthesiology. 2001 Oct;95(4):836-41. doi: 10.1097/00000542-200110000-00009.
- BackgroundBannister FB, Macbeth RG. Direct laryngoscopy and tracheal intubation. Lancet 1944; 2: 651-4
- Background: PubMed 20846964Greenland KB, Edwards MJ, Hutton NJ, Challis VJ, Irwin MG, Sleigh JW. Changes in airway configuration with different head and neck positions using magnetic resonance imaging of normal airways: a new concept with possible clinical applications. Br J Anaesth. 2010 Nov;105(5):683-90. doi: 10.1093/bja/aeq239. Epub 2010 Sep 15.
- BackgroundJackson C. Bronchoscopy and Esophagoscopy: A Manual of Peroral Endoscopy and Laryngeal Surgery. Philadelphia and London: WB Saunders; 1922
- Background: PubMed 17611252Lee BJ, Kang JM, Kim DO. Laryngeal exposure during laryngoscopy is better in the 25 degrees back-up position than in the supine position. Br J Anaesth. 2007 Oct;99(4):581-6. doi: 10.1093/bja/aem095. Epub 2007 Jul 4.
- Background: PubMed 24355831Lee HC, Yun MJ, Hwang JW, Na HS, Kim DH, Park JY. Higher operating tables provide better laryngeal views for tracheal intubation. Br J Anaesth. 2014 Apr;112(4):749-55. doi: 10.1093/bja/aet428. Epub 2013 Dec 18.
- Background: PubMed 19020138Rao SL, Kunselman AR, Schuler HG, DesHarnais S. Laryngoscopy and tracheal intubation in the head-elevated position in obese patients: a randomized, controlled, equivalence trial. Anesth Analg. 2008 Dec;107(6):1912-8. doi: 10.1213/ane.0b013e31818556ed.
- Background: PubMed 15527629Collins JS, Lemmens HJ, Brodsky JB, Brock-Utne JG, Levitan RM. Laryngoscopy and morbid obesity: a comparison of the "sniff" and "ramped" positions. Obes Surg. 2004 Oct;14(9):1171-5. doi: 10.1381/0960892042386869.
- Background: PubMed 16229689Lane S, Saunders D, Schofield A, Padmanabhan R, Hildreth A, Laws D. A prospective, randomised controlled trial comparing the efficacy of pre-oxygenation in the 20 degrees head-up vs supine position. Anaesthesia. 2005 Nov;60(11):1064-7. doi: 10.1111/j.1365-2044.2005.04374.x.
- Background: PubMed 15915022Dixon BJ, Dixon JB, Carden JR, Burn AJ, Schachter LM, Playfair JM, Laurie CP, O'Brien PE. Preoxygenation is more effective in the 25 degrees head-up position than in the supine position in severely obese patients: a randomized controlled study. Anesthesiology. 2005 Jun;102(6):1110-5; discussion 5A. doi: 10.1097/00000542-200506000-00009.
- Background: PubMed 22301204Lebowitz PW, Shay H, Straker T, Rubin D, Bodner S. Shoulder and head elevation improves laryngoscopic view for tracheal intubation in nonobese as well as obese individuals. J Clin Anesth. 2012 Mar;24(2):104-8. doi: 10.1016/j.jclinane.2011.06.015. Epub 2012 Feb 1.
- Derived from this study: PubMed 27852241Reddy RM, Adke M, Patil P, Kosheleva I, Ridley S; Anaesthetic Department at Glan Clwyd Hospital. Comparison of glottic views and intubation times in the supine and 25 degree back-up positions. BMC Anesthesiol. 2016 Nov 16;16(1):113. doi: 10.1186/s12871-016-0280-4.
- Individual participant dataSharing planned: Yes. Publish anonymised raw data as supplementary file
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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.
Raj M Reddy, FRCA principal investigator
Anaesthetic Department, Glan Clwyd Hospital, Betsi Cadwaladr University Health Board
Questions about this trial
What is this clinical trial studying?
An observational study of Elective Surgical Patients, run by Betsi Cadwaladr University Health Board.
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 4 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 11 May 2017. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. 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?
Yes. Results are posted in the registry (first posted 30 Mar 2017). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
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?
The Best Glottic View Obtained During Laryngoscopy (time frame: The view of the glottis was measured once while the patient was being intubated). 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 NCT02934347, which also lists 12 linked publications.
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 11 May 2017.